Sup doods. I've been playing around with some logic lately. Kind of a fun little proof. Let me know what you think. I don't normally put formal logic stuff like this up here, but I figured I'd just see how it goes. Maybe you guys will appreciate this more than my prose type stuff. I dunno.
Some background information...
Classical free will is defined as "the ability to do otherwise." That is, if we have classical free will, then it means that when we do an action, it was possible that we could have made a different choice. For example, we could always just hold our breath and die instead of doing the action.
The classical free will thesis is just the thesis that says we have classical free will.
Hokay. So here it is:
Proof: The classical free will thesis is false.
If the classical free will thesis is correct, that is, if we have classical free will, then the following proposition is true:
Proposition (The classical definition of free will): If an agent did some action A, then it was possible for the agent to have done some contrary action B.
Definition: Two actions are contrary actions if an agent cannot perform both of them.
Contrapositive of the proposition: If it was not possible for the agent to have done B, then the agent did not do A.
We will attempt to disprove the proposition by showing that its logically equivalent contrapositive leads to a contradiction.
So we assume (for reductio) that it was not possible for the agent to have done B. If the proposition is true, then it should follow that the agent did not do A. We will show that this is not the case.
Let B* be the proposition that the agent performs action B, and let A* be the proposition that the agent performs action A.
Note that B is defined as an action contrary to A.
So by definition of B, we get the bi-conditional:
(1) B* <-> ~A*
This can be broken into the following:
(2) B* -> ~A* (3) ~A* -> B*
Recall that we have assumed that B is not possible. Since B is not possible, we deduce: (4) ~B*. Thus, (5) ~B* -> ~~A* by (3) Contraposition (6) ~B* -> A* by (4) Double Negative Elimination Therefore, (7) A* by (4)(6) Modus Ponens
Thus we have shown that if B was not possible, then the agent must have done A.
Therefore, it follows from our proposition:
(8) "If it was not possible for the agent to have done B, then the agent did not do A."
that it was possible for the agent to have done B. (By (7)(8) Modus Tollens)
Therefore we have the following contradiction: (P) It was not possible for the agent to have done B (assumed for reductio) (Q) It was possible for the agent to have done B (deduced from (P))
Since our proposition defending classical free will leads to a contradiction, the proposition must be false. Because the proposition is false, the classical free will thesis is thus false by Modus Tollens.
Indeed. Id even say free will as a concept can only be True if all human are equal (in all possible ways) and are not in need of essentials like food. As long as anyone has more power than me my will is not free. It may appear as though I have a free will. But since the goal for all is to live, I have very limited choice.
On May 29 2014 06:05 SamuelGreen wrote: Indeed. Id even say free will as a concept can only be True if all human are equal (in all possible ways) and are not in need of essentials like food. As long as anyone has more power than me my will is not free. It may appear as though I have a free will. But since the goal for all is to live, I have very limited choice.
Just sayin.
Ok so a few things:
The goal for all is not necessarily to live. Suicide is a thing. Self Sacrifice for greater causes is a thing.
The question of free will is not a question of power or obedience. One with more power than you might be able to force you to do an action, and impose his will upon you such that you are a means to his end. However, nobody can ever force you to will that his end become your own. Coercion is against the will. The will itself remains unmoved.
What we're really talking about here is more like,
"If God knows everything that I will ever do, how can I ever do anything other than that?"
Or,
"If everything in the world since the big bang is governed by natural laws (like the laws of physics and whatnot), then are all my choices not just the product of a chain of cause and effect? In which case, is it possible for me to freely make a choice at all? Or is it the case that I was always going to do what I did and I never could have made any other choice?"
Even though I don't believe in free will this isn't a very good argument. Basically you said that A and B=NOT A need to be both possible for free will to exist. And then (with some added unnecessary operations) concluded that it's impossible because A and NOT A can't simultaneously be true (something can't be both true and false).
So this is just the old argument that any proposition (even those about the future) must be either true or false right now. In other words you've concluded that free will doesn't exist by assuming that logical determinism is true.
On May 29 2014 05:21 MichaelDonovan wrote: ... Note that B is defined as an action contrary to A.
So by definition of B, we get the bi-conditional:
(1) B* <-> ~A*
...
I'm confused here. How can you make the statement that B is defined as contrary to A?
That's just what we defined B to be in the original proposition. B is some action contrary to A.
The way you are doing it, you are already negating free will in the premise itself.
The original proposition is A* -> B*. Saying B is contrary to A already contradicts this statement. That means, you can say B* IS NOT A*. But you cannot say, IF B* THEN NOT A*.
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On May 29 2014 06:17 spinesheath wrote: So you have a contradiction if you assume that there is some B that was not possible.
Then obviously everything is possible.
I don't think I understand what you're getting at.
If hes thinking the same thing i am, then this: You are offering 2 possibilities and for the sake of your "proof" and then you are beforehand excluding the B. It think your proof is wrong: first of all, you are not limited to 2 choices. The choices are virtually infinite, and the only boundary to them is exactly how they say your imagination. If you can imagine it, then it is possible, if it respects the laws of physics. In a situation where you are presented with 2 different choices, you have more than 2. Its just you are not able to imagine having more than 2. Therefore the rest of the theory is wrong
In my opinion Free will exists and it is simply not applied most of the time. What generally people think is free will is defiled by peoples thoughts, their dreams, there desire to appear a certain way. Many a time do people do act of of free will.
Also sorry to say your example of breathing is wrong. The act of breathing is carried out most of the time and while you sleep by the sub-counscious mind. While you and me and any human being do excerise an amount of control over it, like holding your breath underwater, i dare you to find me 1 example of someone who stopped breathing volontairly, WITHOUT external influeces like say a bag for suffocation or a moment of extreme shock.
I also think that the assumption that "if I don't do A, then I must have done B" seems like the weak point. Otherwise the deductions seems to hold. You know that there is a branch of modal logic that deals with possibilities and necessities right? Using them you could formalize the entire thing much more.
I do believe in free will, in the compatibilist sense, however it does nothing against your argumentation. Logic is about whether things can be deduced from assumptions or not, but it doesn't care about if we like the the assumptions or the conclusion. If the reasoning is sound, it is sound. Check out Gödel's ontological proof for crazy assumptions.
On May 29 2014 06:17 spinesheath wrote: So you have a contradiction if you assume that there is some B that was not possible.
Then obviously everything is possible.
I don't think I understand what you're getting at.
If hes thinking the same thing i am, then this: You are offering 2 possibilities and for the sake of your "proof" and then you are beforehand excluding the B. It think your proof is wrong: first of all, you are not limited to 2 choices. The choices are virtually infinite, and the only boundary to them is exactly how they say your imagination. If you can imagine it, then it is possible, if it respects the laws of physics. In a situation where you are presented with 2 different choices, you have more than 2. Its just you are not able to imagine having more than 2. Therefore the rest of the theory is wrong
In my opinion Free will exists and it is simply not applied most of the time. What generally people think is free will is defiled by peoples thoughts, their dreams, there desire to appear a certain way. Many a time do people do act of of free will.
Also sorry to say your example of breathing is wrong. The act of breathing is carried out most of the time and while you sleep by the sub-counscious mind. While you and me and any human being do excerise an amount of control over it, like holding your breath underwater, i dare you to find me 1 example of someone who stopped breathing volontairly, WITHOUT external influeces like say a bag for suffocation or a moment of extreme shock.
B is not any particular action. B can just be anything contrary to A. So A is one action, and B is everything else.
Whether or not there are infiinite options or just two is not relevant to the question. In fact it's probably easier and better to just imagine for the sake of argument that there are only two options to keep it simple. Let's say you ONLY have two options. If you have classical free will, and you choose to do the first option, then it must be true that the second option was possible (and that you weren't fated to do the first option). This whole business about "infinite possibilities" is beside the point.
We are excluding the B before hand merely as a logical consequence of contraposition. Basically what it's saying is that if there was no contrary action possible in a world with classical free will, then the only possible explanation for this is that there was no original action A for it to be contrary to.
That's kind of a hazy way to talk about it, so let's just stick to the logic:
(1) If P then Q. The contrapositive of (1) is: (2) If not Q then not P.
Statements (1) and two (2) are logically equivalent, so disproving the statement in either form works just the same. I put the original proposition in its contrapositive form so that it's easier to work with logically.
The breathing example was just a hasty one. Basically all I mean by that is that if classical free will exists, then it's always possible that you could have not done what you did. Even if it seems like your options are really narrow, it's always possible to just remain inactive and not do the action, at least, if there are no other options. Like, it might seem like the only choice I have is to walk the plank, since the pirate is pointing his sword at me, but I always have the option of making him stab me or push me off the plank instead of jumping myself. I dunno these examples are all non-formal ones so it's easy to poke holes in them, but they are kind of beside the point since they are just illustrative.
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
On May 29 2014 05:21 MichaelDonovan wrote: ... Note that B is defined as an action contrary to A.
So by definition of B, we get the bi-conditional:
(1) B* <-> ~A*
...
I'm confused here. How can you make the statement that B is defined as contrary to A?
That's just what we defined B to be in the original proposition. B is some action contrary to A.
The way you are doing it, you are already negating free will in the premise itself. I think you are mixing up the meaning of contrary.
The original proposition is A* -> B*. And B is contrary to A. That means, you can say B* IS NOT A*. But you cannot say, IF B* THEN NOT A*.
The original proposition is:
If an agent did some action A, then it was possible for him to have done some contrary action B.
So there it is. B is an action contrary to A. That's just what it's defined as.
Who has come up with this definition of free will? Is this how logic defines free will?
It says that A* -> B* and A* -> ~B*. This is in itself already a contradiction. There is no need to further prove or disprove it. The proposition itself returns already a false statement!
On May 29 2014 07:08 airen wrote: I also think that the assumption that "if I don't do A, then I must have done B" seems like the weak point. Otherwise the deductions seems to hold. You know that there is a branch of modal logic that deals with possibilities and necessities right? Using them you could formalize the entire thing much more.
I do believe in free will, in the compatibilist sense, however it does nothing against your argumentation. Logic is about whether things can be deduced from assumptions or not, but it doesn't care about if we like the the assumptions or the conclusion. If the reasoning is sound, it is sound. Check out Gödel's ontological proof for crazy assumptions.
Well since B is by definition any action contrary to A, then the action of not doing A (perhaps even the choice of remaining inactive and not doing anything) is contained in B by definition. Does that make sense?
Regarding the modal bit, I actually wrote this proof in such away as to do away with modality. I wrote it so that it doesn't need modal logic in order to be valid. The only part where I use modal logic is where I say:
"Since we assume B is not possible (or ~PB or something like that), we conclude ~B*."
That is, since we assume B isn't possible, it follows that the agent could not have done B.
On May 29 2014 05:21 MichaelDonovan wrote: ... Note that B is defined as an action contrary to A.
So by definition of B, we get the bi-conditional:
(1) B* <-> ~A*
...
I'm confused here. How can you make the statement that B is defined as contrary to A?
That's just what we defined B to be in the original proposition. B is some action contrary to A.
The way you are doing it, you are already negating free will in the premise itself. I think you are mixing up the meaning of contrary.
The original proposition is A* -> B*. And B is contrary to A. That means, you can say B* IS NOT A*. But you cannot say, IF B* THEN NOT A*.
The original proposition is:
If an agent did some action A, then it was possible for him to have done some contrary action B.
So there it is. B is an action contrary to A. That's just what it's defined as.
Who has come up with this definition of free will? Is this how logic defines free will?
It says that A* -> B* and A* -> ~B*. This is in itself already a contradiction. There is no need to further proof or disprove it. The proposition itself returns already a false statement!
Classical free will is the old definition of free will that philosophers had been using for a very long time. It just defines free will as the ability to do otherwise. Meaning, if you did something, then looking back you could have chosen to do something else. Basically meaning that you aren't pidgeon holed into one choice by fatalism.
There are no a few other definitions of free will that compete with the classical version. I'm just tackling the logical inconsistency of the classical view here. I'm not showing that free will doesn't exist. I'm just showing that the classical free will thesis is incoherent.
Also, I think you might be misunderstanding the logic a bit.
What we have is the biconditional: B* -> ~A* and ~A* -> B*.
This is just from that definition of contrary action which says that you can't do both of them. Like you can't both slap your girlfriend on the ass and also not slap her on the ass. You either slap her on the ass, or you do something else.
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
That's because philosophers love to argue. Until the real scientist comes along and puts the matter to rest with empiric evidence instead of pure thought .
Facetiousness aside, you should really watch the video. Sam makes a compelling argument on why the very concept of free will doesn't really make sense.
On May 29 2014 06:36 L3gendary wrote: Even though I don't believe in free will this isn't a very good argument. Basically you said that A and B=NOT A need to be both possible for free will to exist. And then (with some added unnecessary operations) concluded that it's impossible because A and NOT A can't simultaneously be true (something can't be both true and false).
So this is just the old argument that any proposition (even those about the future) must be either true or false right now. In other words you've concluded that free will doesn't exist by assuming that logical determinism is true.
Not quite...
First it's important to note that I'm not saying that free will doesn't exist. What I'm saying is that the classical free will thesis is incoherent. It's still perfectly possible that free will could exist (like the source view or something), but the classical free will thesis is logically incoherent.
The ability to do otherwise, or the retrospective possibility of having done something else is what I'm arguing against. All of my arguments come merely as a consequence of the classical definition of free will. Does that make sense?
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
That's because philosophers love to argue. Until the real scientist comes along and puts the matter to rest with empiric evidence instead of pure thought .
Facetiousness aside, you should really watch the video. Sam makes a compelling argument on why the very concept of free will doesn't really make sense.
Empirical evidence is hard to rely on when our sense perception is so limited
There are really two versions of the world: The world as we perceive it to be and the world as it actually is outside of our experience of it. Truth can be found in the world as it actually is. What we perceive is only contingent on the accuracy and completeness of our sense perception. The only way to get at the way the world actually is, it would seem, through rational thought and deductive reasoning. A fairly lofty task though, to be sure.
Started watching the video. So far it seems like a kind of "Free Will for Dummies" thing. He's just kind of going over the most well known arguments against free will. It also seems like he's relying pretty heavily relying on the classical definition of free will. There are other ways of defining free will besides "the ability to do otherwise."
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
That's because philosophers love to argue. Until the real scientist comes along and puts the matter to rest with empiric evidence instead of pure thought .
Facetiousness aside, you should really watch the video. Sam makes a compelling argument on why the very concept of free will doesn't really make sense.
Empirical evidence is hard to rely on when our sense perception is so limited
There are really two versions of the world: The world as we perceive it to be and the world as it actually is outside of our experience of it. Truth can be found in the world as it actually is. What we perceive is only contingent on the accuracy and completeness of our sense perception. The only way to get at the way the world actually is, it would seem, through rational thought and deductive reasoning. A fairly lofty task though, to be sure.
Empirical evidence is hard to rely on? Is that why science doesn't make any progress?
The best method that we have to find out truth about the world, an objective truth, is scientific method. Rational thought and deductive reasoning go out the window once we're confronted with something that doesn't seem rational, eg. quantum mechanics.
On May 29 2014 05:21 MichaelDonovan wrote: ... Note that B is defined as an action contrary to A.
So by definition of B, we get the bi-conditional:
(1) B* <-> ~A*
...
I'm confused here. How can you make the statement that B is defined as contrary to A?
That's just what we defined B to be in the original proposition. B is some action contrary to A.
The way you are doing it, you are already negating free will in the premise itself. I think you are mixing up the meaning of contrary.
The original proposition is A* -> B*. And B is contrary to A. That means, you can say B* IS NOT A*. But you cannot say, IF B* THEN NOT A*.
The original proposition is:
If an agent did some action A, then it was possible for him to have done some contrary action B.
So there it is. B is an action contrary to A. That's just what it's defined as.
Who has come up with this definition of free will? Is this how logic defines free will?
It says that A* -> B* and A* -> ~B*. This is in itself already a contradiction. There is no need to further proof or disprove it. The proposition itself returns already a false statement!
Classical free will is the old definition of free will that philosophers had been using for a very long time. It just defines free will as the ability to do otherwise. Meaning, if you did something, then looking back you could have chosen to do something else. Basically meaning that you aren't pidgeon holed into one choice by fatalism.
There are no a few other definitions of free will that compete with the classical version. I'm just tackling the logical inconsistency of the classical view here. I'm not showing that free will doesn't exist. I'm just showing that the classical free will thesis is incoherent.
Also, I think you might be misunderstanding the logic a bit.
What we have is the biconditional: B* -> ~A* and ~A* -> B*.
This is just from that definition of contrary action which says that you can't do both of them. Like you can't both slap your girlfriend on the ass and also not slap her on the ass. You either slap her on the ass, or you do something else.
I see, I'm not too familiar with logic, so maybe I'm misunderstanding something.
Can't you express the contrary action in a simpler way? Instead of writing it like this: B* -> ~A* and ~A* -> B* You can just write B* -> ~A and A* -> ~B*. Is this correct?
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
That's because philosophers love to argue. Until the real scientist comes along and puts the matter to rest with empiric evidence instead of pure thought .
Facetiousness aside, you should really watch the video. Sam makes a compelling argument on why the very concept of free will doesn't really make sense.
Empirical evidence is hard to rely on when our sense perception is so limited
There are really two versions of the world: The world as we perceive it to be and the world as it actually is outside of our experience of it. Truth can be found in the world as it actually is. What we perceive is only contingent on the accuracy and completeness of our sense perception. The only way to get at the way the world actually is, it would seem, through rational thought and deductive reasoning. A fairly lofty task though, to be sure.
Empirical evidence is hard to rely on? Is that why science doesn't make any progress?
The best method that we have to find out truth about the world, an objective truth, is scientific method. Rational thought and deductive reasoning go out the window once we're confronted with something that doesn't seem rational, eg. quantum mechanics.
Well the problem is that empirical evidence isn't foolproof. We can only gather evidence from what we can sense. How do we know we're not in the matrix world, for example? We don't really know that do we? No amount of empirical evidence can prove that we aren't dreaming or that we aren't just brains in vats being stimulated with the illusion of experience. This is because any empirical evidence we gather is contingent upon our trust for our ability to sense it.
Quantum mechanics is not irrational necessarily. It just defies some our previous assumptions about the world. It renders many statements false that were once though to be true. That doesn't mean it's logically incoherent. It just means we don't understand it based on our current assumptions.
Why not just say ~A instead of B, which makes clear immediately your line of thinking, and refocuses us on the real issue, which is what is the meaning exactly of saying "it was possible to do otherwise"?
On May 29 2014 05:21 MichaelDonovan wrote: ... Note that B is defined as an action contrary to A.
So by definition of B, we get the bi-conditional:
(1) B* <-> ~A*
...
I'm confused here. How can you make the statement that B is defined as contrary to A?
That's just what we defined B to be in the original proposition. B is some action contrary to A.
The way you are doing it, you are already negating free will in the premise itself. I think you are mixing up the meaning of contrary.
The original proposition is A* -> B*. And B is contrary to A. That means, you can say B* IS NOT A*. But you cannot say, IF B* THEN NOT A*.
The original proposition is:
If an agent did some action A, then it was possible for him to have done some contrary action B.
So there it is. B is an action contrary to A. That's just what it's defined as.
Who has come up with this definition of free will? Is this how logic defines free will?
It says that A* -> B* and A* -> ~B*. This is in itself already a contradiction. There is no need to further proof or disprove it. The proposition itself returns already a false statement!
Classical free will is the old definition of free will that philosophers had been using for a very long time. It just defines free will as the ability to do otherwise. Meaning, if you did something, then looking back you could have chosen to do something else. Basically meaning that you aren't pidgeon holed into one choice by fatalism.
There are no a few other definitions of free will that compete with the classical version. I'm just tackling the logical inconsistency of the classical view here. I'm not showing that free will doesn't exist. I'm just showing that the classical free will thesis is incoherent.
Also, I think you might be misunderstanding the logic a bit.
What we have is the biconditional: B* -> ~A* and ~A* -> B*.
This is just from that definition of contrary action which says that you can't do both of them. Like you can't both slap your girlfriend on the ass and also not slap her on the ass. You either slap her on the ass, or you do something else.
I see, I'm not too familiar with logic, so maybe I'm misunderstanding something.
Can't you express the contrary action in a simpler way? Instead of writing it like this: B* -> ~A* and ~A* -> B* You can just write B* -> ~A and A* -> ~B*. Is this correct?
It's correct, but there are intermediate steps to getting there.
You start with the biconditional: B <-> ~A
It goes both ways so you can break it up into two separate statements: B -> ~A (B implies not A) ~A -> B (not A implies B)
And then if you take the contrapostive of B -> ~A which is: ~~A -> ~B (not not A implies not B)
Then the two negatives cancel and you get ~B -> A (not B implies A)
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
That's because philosophers love to argue. Until the real scientist comes along and puts the matter to rest with empiric evidence instead of pure thought .
Facetiousness aside, you should really watch the video. Sam makes a compelling argument on why the very concept of free will doesn't really make sense.
Empirical evidence is hard to rely on when our sense perception is so limited
There are really two versions of the world: The world as we perceive it to be and the world as it actually is outside of our experience of it. Truth can be found in the world as it actually is. What we perceive is only contingent on the accuracy and completeness of our sense perception. The only way to get at the way the world actually is, it would seem, through rational thought and deductive reasoning. A fairly lofty task though, to be sure.
Empirical evidence is hard to rely on? Is that why science doesn't make any progress?
The best method that we have to find out truth about the world, an objective truth, is scientific method. Rational thought and deductive reasoning go out the window once we're confronted with something that doesn't seem rational, eg. quantum mechanics.
Well the problem is that empirical evidence isn't foolproof. We can only gather evidence from what we can sense. How do we know we're not in the matrix world, for example? We don't really know that do we? No amount of empirical evidence can prove that we aren't dreaming or that we aren't just brains in vats being stimulated with the illusion of experience. This is because any empirical evidence we gather is contingent upon our trust for our ability to sense it.
Quantum mechanics is not irrational necessarily. It just defies some our previous assumptions about the world. It renders many statements false that were once though to be true. That doesn't mean it's logically incoherent. It just means we don't understand it based on our current assumptions.
Were you arguing in a thread once with frogrubdown about the idea of the demon that tricks you into thinking your rational deduction is true when it really isn't? In other words, you are still relying on sense perception of a sort when you "know" that your rational thought process has delivered a truth. So you can't do better than "fuck it let's science", or so it is suggested. (And of course I'm saying science with some facetious looseness.)
Or maybe that wasn't you, but have you run into this demon idea before?
On May 29 2014 07:57 EatThePath wrote: Why not just say ~A instead of B, which makes clear immediately your line of thinking, and refocuses us on the real issue, which is what is the meaning exactly of saying "it was possible to do otherwise"?
But nevertheless it was a good exercise. ^^
I say B instead of ~A because saying ~A can cause people to misunderstand it to mean only one action (the action of not doing A).
If I say B is any action contrary to A, then it's clear that B contains many possibilities.
First a formal thing to point out: your quantifiers are mixed up at the start: you say that - not (it was possible for the agent to have done some contrary action B) is - it was not possible for the agent to have done B.
But the correct negation would be - it was not possible to do any action contrary to A. You are pulling a specific B out of nowhere; there might be a whole load of actions contrary to A
There is another problem (which is maybe bigger): you state that if A and B are contrary then not doing A implies doing B. This doesn't follow from your definition of contrary, you would need to change your definition of contrary to - A and B are contrary if one cannot do both and must do one of the two. Now I think all you are saying is that one must do one of A or not A.
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
That's because philosophers love to argue. Until the real scientist comes along and puts the matter to rest with empiric evidence instead of pure thought .
Facetiousness aside, you should really watch the video. Sam makes a compelling argument on why the very concept of free will doesn't really make sense.
Empirical evidence is hard to rely on when our sense perception is so limited
There are really two versions of the world: The world as we perceive it to be and the world as it actually is outside of our experience of it. Truth can be found in the world as it actually is. What we perceive is only contingent on the accuracy and completeness of our sense perception. The only way to get at the way the world actually is, it would seem, through rational thought and deductive reasoning. A fairly lofty task though, to be sure.
Empirical evidence is hard to rely on? Is that why science doesn't make any progress?
The best method that we have to find out truth about the world, an objective truth, is scientific method. Rational thought and deductive reasoning go out the window once we're confronted with something that doesn't seem rational, eg. quantum mechanics.
Well the problem is that empirical evidence isn't foolproof. We can only gather evidence from what we can sense. How do we know we're not in the matrix world, for example? We don't really know that do we? No amount of empirical evidence can prove that we aren't dreaming or that we aren't just brains in vats being stimulated with the illusion of experience. This is because any empirical evidence we gather is contingent upon our trust for our ability to sense it.
Quantum mechanics is not irrational necessarily. It just defies some our previous assumptions about the world. It renders many statements false that were once though to be true. That doesn't mean it's logically incoherent. It just means we don't understand it based on our current assumptions.
Were you arguing in a thread once with frogrubdown about the idea of the demon that tricks you into thinking your rational deduction is true when it really isn't? In other words, you are still relying on sense perception of a sort when you "know" that your rational thought process has delivered a truth. So you can't do better than "fuck it let's science", or so it is suggested. (And of course I'm saying science with some facetious looseness.)
Or maybe that wasn't you, but have you run into this demon idea before?
That was not me arguing. But I am familiar with this example as any philosopher should be. It is an old example from Descartes. It's a pretty strong skeptical example and it's not really clear how to get around it. There's no real way for me to know with certainty that I'm not being manipulated by an evil being in this way.
At this point, my answer for skepticism in general is that you can't really get around it. There will always be some kind of skeptical thesis that refutes your belief. So what we have to do in order to move on from this is just acknowledge that all of our conclusions are contingent on there not being a demon manipulating me. That is, anything I conclude with logic must be believed true only under the assumption that logic is a reliable method of deriving truth.
On May 29 2014 08:07 sOda~ wrote: First a formal thing to point out: your quantifiers are mixed up at the start: you say that - not (it was possible for the agent to have done some contrary action B) is - it was not possible for the agent to have done B.
But the correct negation would be - it was not possible to do any action contrary to A. You are pulling a specific B out of nowhere; there might be a whole load of actions contrary to A
There is another problem (which is maybe bigger): you state that if A and B are contrary then not doing A implies doing B. This doesn't follow from your definition of contrary, you would need to change your definition of contrary to - A and B are contrary if one cannot do both and must do one of the two. Now I think all you are saying is that one must do one of A or not A.
he already stated that B isnt a single action but everything not A
On May 29 2014 05:21 MichaelDonovan wrote: Proof: The classical free will thesis is false.
If the classical free will thesis is correct, that is, if we have classical free will, then the following proposition is true:
Proposition (The classical definition of free will):If an agent did some action A, then it was possible for the agent to have done some contrary action B.
Definition: Two actions are contrary actions if an agent cannot perform both of them.
Contrapositive of the proposition: If it was not possible for the agent to have done B, then the agent did not do A.
My issue is with the red above.
I don't think the statement actually says what you intend for it to say. Let me try rewording it:
Proposition: If an agent did some action (A), then there exists at least one contrary action that the agent could have done instead. Contrapositive: If no contrary action to action (A) exists, then an agent could not have taken action (A).
This of course assumes that every action has an alternative, which may or may not be too strong of a definition for free will. Even if this assumption is disproved, you haven't really accomplished much since free will, in general, can still exist. Regardless, I find the way I phrased the proposition less confusing and error-prone. Frankly, I'm not sure if I can follow your analysis beyond there without reading up on philosophical logic, but usually in these types of situations the phrasing of the initial statements is the most important part of avoiding weird or invalid conclusions.... or confusion from your readers.
On May 29 2014 08:07 sOda~ wrote: First a formal thing to point out: your quantifiers are mixed up at the start: you say that - not (it was possible for the agent to have done some contrary action B) is - it was not possible for the agent to have done B.
But the correct negation would be - it was not possible to do any action contrary to A. You are pulling a specific B out of nowhere; there might be a whole load of actions contrary to A
There is another problem (which is maybe bigger): you state that if A and B are contrary then not doing A implies doing B. This doesn't follow from your definition of contrary, you would need to change your definition of contrary to - A and B are contrary if one cannot do both and must do one of the two. Now I think all you are saying is that one must do one of A or not A.
My response to your first objection is that B is defined as some action contrary to A. When I say this, I am not saying that B is a particular action. I really mean the same thing as B is defined as any action contrary to A. So "some action" and "any action" are the same thing here. Doing B amounts to doing otherwise, basically. Does that make sense?
And to your second objection what I would say is that not doing A is an action in itself, and it is an action clearly contrary to A. So it is contained in B. If you don't do A, then that's a contrary choice to A. And yes, it is the case that you must either do A or not A. That's just a consequence of not being able to do both. They are mutually exclusive and exhaustive.
On May 29 2014 07:57 EatThePath wrote: Why not just say ~A instead of B, which makes clear immediately your line of thinking, and refocuses us on the real issue, which is what is the meaning exactly of saying "it was possible to do otherwise"?
But nevertheless it was a good exercise. ^^
I say B instead of ~A because saying ~A can cause people to misunderstand it to mean only one action (the action of not doing A).
If I say B is any action contrary to A, then it's clear that B contains many possibilities.
It's just for clarity's sake.
Yeah, but from the other perspective it just makes it seem like you are smuggling a problem into a non-issue (or at least a trivial one) by obfuscating the situation with an extra layer of description. I am sorry to sound belittling I don't mean it that way. Let me try and be constructive:
If you say "If you did A, then it was possible to do ~A [anything other than A]" and take the contrapositive "If ~A was precluded, then you did not do A", the only takeaway is that nothing is possible -- a silly state of affairs -- which I think is what that earlier poster was getting at.
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
That's because philosophers love to argue. Until the real scientist comes along and puts the matter to rest with empiric evidence instead of pure thought .
Facetiousness aside, you should really watch the video. Sam makes a compelling argument on why the very concept of free will doesn't really make sense.
Empirical evidence is hard to rely on when our sense perception is so limited
There are really two versions of the world: The world as we perceive it to be and the world as it actually is outside of our experience of it. Truth can be found in the world as it actually is. What we perceive is only contingent on the accuracy and completeness of our sense perception. The only way to get at the way the world actually is, it would seem, through rational thought and deductive reasoning. A fairly lofty task though, to be sure.
Empirical evidence is hard to rely on? Is that why science doesn't make any progress?
The best method that we have to find out truth about the world, an objective truth, is scientific method. Rational thought and deductive reasoning go out the window once we're confronted with something that doesn't seem rational, eg. quantum mechanics.
Well the problem is that empirical evidence isn't foolproof. We can only gather evidence from what we can sense. How do we know we're not in the matrix world, for example? We don't really know that do we? No amount of empirical evidence can prove that we aren't dreaming or that we aren't just brains in vats being stimulated with the illusion of experience. This is because any empirical evidence we gather is contingent upon our trust for our ability to sense it.
Quantum mechanics is not irrational necessarily. It just defies some our previous assumptions about the world. It renders many statements false that were once though to be true. That doesn't mean it's logically incoherent. It just means we don't understand it based on our current assumptions.
Were you arguing in a thread once with frogrubdown about the idea of the demon that tricks you into thinking your rational deduction is true when it really isn't? In other words, you are still relying on sense perception of a sort when you "know" that your rational thought process has delivered a truth. So you can't do better than "fuck it let's science", or so it is suggested. (And of course I'm saying science with some facetious looseness.)
Or maybe that wasn't you, but have you run into this demon idea before?
That was not me arguing. But I am familiar with this example as any philosopher should be. It is an old example from Descartes. It's a pretty strong skeptical example and it's not really clear how to get around it. There's no real way for me to know with certainty that I'm not being manipulated by an evil being in this way.
At this point, my answer for skepticism in general is that you can't really get around it. There will always be some kind of skeptical thesis that refutes your belief. So what we have to do in order to move on from this is just acknowledge that all of our conclusions are contingent on there not being a demon manipulating me. That is, anything I conclude with logic must be believed true only under the assumption that logic is a reliable method of deriving truth.
Ah okay. I wish I remembered these things instead of just referring to them vaguely, so thanks for understanding. /armchair philosophy
On May 29 2014 05:21 MichaelDonovan wrote: Proof: The classical free will thesis is false.
If the classical free will thesis is correct, that is, if we have classical free will, then the following proposition is true:
Proposition (The classical definition of free will):If an agent did some action A, then it was possible for the agent to have done some contrary action B.
Definition: Two actions are contrary actions if an agent cannot perform both of them.
Contrapositive of the proposition: If it was not possible for the agent to have done B, then the agent did not do A.
My issue is with the red above.
I don't think the statement actually says what you intend for it to say. Let me try rewording it:
Proposition: If an agent did some action (A), then there exists at least one contrary action that the agent could have done instead. Contrapositive: If no contrary action to action (A) exists, then an agent could not have taken action A.
This of course assumes that every action has an alternative, which may or may not be too strong of a definition for free will. Even if this assumption is disproved, you haven't really accomplished much since free will, in general, can still exist. Regardless, I find the way I phrased the proposition less confusing and error-prone. Frankly, I'm not sure if I can follow your analysis beyond there without reading up on philosophical logic, but usually in these types of situations the phrasing of the initial statements is the most important part of avoiding weird or invalid conclusions.
I think I like your phrasing of the proposition more than mine as well, thank you. But the argument following from it remains the same. Be sure to understand that I am not attempting to disprove free will in general. I'm just trying to show that the classical definition of free will (the ability to do otherwise) is incoherent. There are definitions of free will (like the source definition of free will) which are unaffected by my argument.
On May 29 2014 05:21 MichaelDonovan wrote: Proof: The classical free will thesis is false.
If the classical free will thesis is correct, that is, if we have classical free will, then the following proposition is true:
Proposition (The classical definition of free will):If an agent did some action A, then it was possible for the agent to have done some contrary action B.
Definition: Two actions are contrary actions if an agent cannot perform both of them.
Contrapositive of the proposition: If it was not possible for the agent to have done B, then the agent did not do A.
My issue is with the red above.
I don't think the statement actually says what you intend for it to say. Let me try rewording it:
Proposition: If an agent did some action (A), then there exists at least one contrary action that the agent could have done instead. Contrapositive: If no contrary action to action (A) exists, then an agent could not have taken action (A).
This of course assumes that every action has an alternative, which may or may not be too strong of a definition for free will. Even if this assumption is disproved, you haven't really accomplished much since free will, in general, can still exist. Regardless, I find the way I phrased the proposition less confusing and error-prone. Frankly, I'm not sure if I can follow your analysis beyond there without reading up on philosophical logic, but usually in these types of situations the phrasing of the initial statements is the most important part of avoiding weird or invalid conclusions.... or confusion from your readers.
I like this rewording much better as well, nice.
On May 29 2014 08:20 micronesia wrote: It's unfortunate that I don't remember the mathematical rules of logic that well, but I don't see how you can use logic alone to prove the following:
It is not possible for every action to have at least one alternative, mutually exclusive action.
I don't think there are enough tools to work with. Putting technical lines of math aside, what is the reason why the above statement is true?
You could start by investigating the definition of action, which might expand into considerations of quite a bit more than you at first assume. As usual it comes back to unpacking what the language is holding, which generally leads to messes and tears and bloodshed.
If you say "If you did A, then it was possible to do ~A [anything other than A]" and take the contrapositive "If ~A was precluded, then you did not do A", the only takeaway is that nothing is possible -- a silly state of affairs -- which I think is what that earlier poster was getting at.
Ok so two things:
First, what I am actually trying to show is that classical free will is in fact a silly state of affairs. So the fact that it seems to be a silly state of affairs is only a consequence of its silliness to begin with.
Second, the way I interpret the contrapositve (since it's not really intuitive to think about when you first look at it) is just that if there is no contrary action B possible, then there was no action A to begin with for it to be contrary to. It's not to say that nothing is possible, but just that nothing happened.
Does that make sense? Maybe still a little hairy..
On May 29 2014 08:22 Paljas wrote: people in this thread need to realise that the proof is correct. the only way to attack it is to dismiss the proposition.
however, id agree with the OP that the classic definition is problematic
No its not: the equivalence in (i) does not follow from the definition of B being contrary to A.
On May 29 2014 08:15 NewEyes wrote: You do know that your assumption already contains what you were trying to proof right?
So far you havent said anything but 'I'll assume the concepts of + and - and i'll assume that 1+1=3, therefore 3-1=1.'
I'm not sure I understand what you're trying to say.
Your assumption is 'B is not possbile' which is equal to A. And then you use this to contradict the statement of 'either A or B is possible'. So basically you just said 'always A' -> 'always A'. While this isnt mathmatically wrong you also havent proven anything because your assumption and your conclusion are both the same. You just phrased them a little differently.
On May 29 2014 08:20 micronesia wrote: It's unfortunate that I don't remember the mathematical rules of logic that well, but I don't see how you can use logic alone to prove the following:
It is not possible for every action to have at least one alternative, mutually exclusive action.
I don't think there are enough tools to work with. Putting technical lines of math aside, what is the reason why the above statement is true?
What you're getting at is the only non-formal assumption that I feel can be poked at in my proof.
My reasoning is as follows:
Recall that we are assuming for reductio that the classical free will thesis is true (we are then showing that a contradiction arises from this).
So since we are assuming classical free will exists, it would seem like no matter how pidgeon-holed into a line of action a person may seem to be, he always has the option of not doing that action, which is a contrary action in itself.
Here's why I say this:
Completing an action requires a break in inertia of sorts. That is, in order to execute an action, one must go from a state of inaction to a state of action and this requires some kind of effort, or at least a willing. If one does not will that the action be executed, they can choose not to act.
The way I think of it is like this: Imagine you are walking on a narrow path over an abyss. You cannot jump off the sides of the path because there is an invisible wall or something. And as you walk, the path behind you gets deleted such that you cannot go the other way. So it would seem as though you have only one choice, which is to continue walking forward. But it turns out that you still have the option of standing still.
I dunno. Maybe this is a weird example. But I think as long as we are assuming free will to exist (for reductio) we can assume that an action that you will should also have an alternative option if you were not to will it. It's easy to imagine a case were you are tide up with a sock in your mouth and you can't move, and say well, there seems to be no other option... But you have the option of willingly accepting your immobility or at least trying to escape (pointless as it may be). The action of accepting your captivity and the action of fighting it (regardless of the effectiveness of your struggle, which may be zero) are contrary actions.
I happily accept that B can represent every possible action that A was not.
This thread was definitely a fun exercise, and the deduction is very interesting. I did some logic a couple of years ago, but never tried to actually apply it to any actual philosophy.
And now I'm kind of bumping my head into the fundamentals of it: you assumed that "it was not possible for the agent to have done B", then you deduce a contradiction from that. But doesn't this just say that the assumption is impossible given the proposition? How does this extend to that "it WAS possible for the agent to have done B" will result in a contradiction along with the proposition? I honestly believe that I'm the one missing something here.
On May 29 2014 08:15 NewEyes wrote: You do know that your assumption already contains what you were trying to proof right?
So far you havent said anything but 'I'll assume the concepts of + and - and i'll assume that 1+1=3, therefore 3-1=1.'
I'm not sure I understand what you're trying to say.
Your assumption is 'B is not possbile' which is equal to A. And then you use this to contradict the statement of 'either A or B is possible'. So basically you just said 'always A' -> 'always A'. While this isnt mathmatically wrong you also havent proven anything because your assumption and your conclusion are both the same. You just phrased them a little differently.
"either A or B is possible" isn't exactly what I'm saying. My assumption isn't that "B is not possible", it's that "if B is not possible, then the agent did not do A". There's more to this proposition than you're including.
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
So the length of time by which we argue something determines how obvious it may or may not be?
On May 29 2014 08:35 airen wrote: I happily accept that B can represent every possible action that A was not.
This thread was definitely a fun exercise, and the deduction is very interesting. I did some logic a couple of years ago, but never tried to actually apply it to any actual philosophy.
And now I'm kind of bumping my head into the fundamentals of it: you assumed that "it was not possible for the agent to have done B", then you deduce a contradiction from that. But doesn't this just say that the assumption is impossible given the proposition? How does this extend to that "it WAS possible for the agent to have done B" will result in a contradiction along with the proposition? I honestly believe that I'm the one missing something here.
Well basically, we assume that B isn't possible. Then logic tells that as a result of B not being possible, that B is possible. This is a logical inconsistency. If you deduce from a statement its opposite, then you have a contradiction and the statement can't be true.
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
So the length of time by which we argue something determines how obvious it may or may not be?
Determines is a wrong word. Indicates is might be better. What I'm saying is that if the guy in this video actually came up with a solution so obvious that you couldn't argue with it, then I would have heard about it by now, and there would be nothing more to argue. But since people are still arguing, his solution can't be all that obvious.
a) You're using classical propositional logic to discuss possibilities, you'd need modal logic for a better representation. "Recall that we have assumed that B is not possible. Since B is not possible, we deduce: (4) ~B*." You can't do this formally without modal logic. And if you use modal logic, make sure you pick a system in which ~Diamond B* entails ~B*.
b) If you do adopt a modal logic, the original thesis would be better described as "at some point (world, time, etc.) where Diamond A holds, Diamond B holds as well."
c) I'm assuming you're utilizing material implication for "->" which has many known puzzles and problems. I don't think we can say much about free will or other concepts in a system in which B makes true A->B, i.e., where sitting in your office, makes true the statement: if you were blown up by a bomb this morning, then you're sitting in your office.
d) To attain (5) you make use of contraposition, but this rule doesn't correspond to our view of rational reasoning with probabilities. Consider Grice's Yog and Zog puzzle:
Yog and Zog are playing chess with special rules. Yog gets white 9/10 times and there are no draws. They have already played around 100 games, and Yog emerged victorious in 80 out of 90 of the games in which Yog had white, but Zog won all the remaining games. Now, the following two sentences have different probabilities.
a. If Yog had white, Yog won. b. If Yog lost, Yog had black.
The probability that the sentence (a) holds is 8/9 but it is only 1/2 for sentence (b). The problem with this situation is that (a) and (b) are equivalent if analyzed as material implication. This is because when you play chess, you use either the white or black pieces. So, playing with not white pieces is the same as playing with black pieces. And losing is the same as not winning when draws are taken out of the rules of chess. So if (a) is represented by p -> q then its contraposition ~q -> ~p is (b). But equivalent sentences should not have different probabilities, 8/9 and 1/2, respectively.
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
So the length of time by which we argue something determines how obvious it may or may not be?
On May 29 2014 08:22 Paljas wrote: people in this thread need to realise that the proof is correct. the only way to attack it is to dismiss the proposition.
however, id agree with the OP that the classic definition is problematic
No its not: the equivalence in (i) does not follow from the definition of B being contrary to A.
If it is the case that you cannot both do A and B (definition of contrary action), and B is any action contrary to A, then the following statements must be true:
If you did B, then you could not have done A. If you did not do A, then you did an action contrary to A, which is contained in B by the proposition. So you did some B.
On May 29 2014 08:20 micronesia wrote: It's unfortunate that I don't remember the mathematical rules of logic that well, but I don't see how you can use logic alone to prove the following:
It is not possible for every action to have at least one alternative, mutually exclusive action.
I don't think there are enough tools to work with. Putting technical lines of math aside, what is the reason why the above statement is true?
What you're getting at is the only non-formal assumption that I feel can be poked at in my proof.
My reasoning is as follows:
Recall that we are assuming for reductio that the classical free will thesis is true (we are then showing that a contradiction arises from this).
So since we are assuming classical free will exists, it would seem like no matter how pidgeon-holed into a line of action a person may seem to be, he always has the option of not doing that action, which is a contrary action in itself.
Here's why I say this:
Completing an action requires a break in inertia of sorts. That is, in order to execute an action, one must go from a state of inaction to a state of action and this requires some kind of effort, or at least a willing. If one does not will that the action be executed, they can choose not to act.
The way I think of it is like this: Imagine you are walking on a narrow path over an abyss. You cannot jump off the sides of the path because there is an invisible wall or something. And as you walk, the path behind you gets deleted such that you cannot go the other way. So it would seem as though you have only one choice, which is to continue walking forward. But it turns out that you still have the option of standing still.
I dunno. Maybe this is a weird example. But I think as long as we are assuming free will to exist (for reductio) we can assume that an action that you will should also have an alternative option if you were not to will it. It's easy to imagine a case were you are tide up with a sock in your mouth and you can't move, and say well, there seems to be no other option... But you have the option of willingly accepting your immobility or at least trying to escape (pointless as it may be). The action of accepting your captivity and the action of fighting it (regardless of the effectiveness of your struggle, which may be zero) are contrary actions.
Everything above seems to be an explanation supporting this classical free will thesis... following along using this plain-English approach, what is the contradiction?
On May 29 2014 08:20 micronesia wrote: It's unfortunate that I don't remember the mathematical rules of logic that well, but I don't see how you can use logic alone to prove the following:
It is not possible for every action to have at least one alternative, mutually exclusive action.
I don't think there are enough tools to work with. Putting technical lines of math aside, what is the reason why the above statement is true?
What you're getting at is the only non-formal assumption that I feel can be poked at in my proof.
My reasoning is as follows:
Recall that we are assuming for reductio that the classical free will thesis is true (we are then showing that a contradiction arises from this).
So since we are assuming classical free will exists, it would seem like no matter how pidgeon-holed into a line of action a person may seem to be, he always has the option of not doing that action, which is a contrary action in itself.
Here's why I say this:
Completing an action requires a break in inertia of sorts. That is, in order to execute an action, one must go from a state of inaction to a state of action and this requires some kind of effort, or at least a willing. If one does not will that the action be executed, they can choose not to act.
The way I think of it is like this: Imagine you are walking on a narrow path over an abyss. You cannot jump off the sides of the path because there is an invisible wall or something. And as you walk, the path behind you gets deleted such that you cannot go the other way. So it would seem as though you have only one choice, which is to continue walking forward. But it turns out that you still have the option of standing still.
I dunno. Maybe this is a weird example. But I think as long as we are assuming free will to exist (for reductio) we can assume that an action that you will should also have an alternative option if you were not to will it. It's easy to imagine a case were you are tide up with a sock in your mouth and you can't move, and say well, there seems to be no other option... But you have the option of willingly accepting your immobility or at least trying to escape (pointless as it may be). The action of accepting your captivity and the action of fighting it (regardless of the effectiveness of your struggle, which may be zero) are contrary actions.
Everything above seems to be an explanation supporting this classical free will thesis... following along using this plain-English approach, what is the contradiction?
The contradiction is probably something like this:
Taking a step forward is a sufficient condition for not having stood still. Not having stood still is a necessary condition for having stepped forward. Having stood still is a sufficient condition for not having stepped forward. Not having stepped forward is a necessary condition for having stood still.
So if I chose to step forward, this makes it the case that I did not choose to stand still. But not having chosen to stand still is the only way that it could have been possible to step forward. Thus, if you stepped forward, it must be the case that standing still was not possible.
On May 29 2014 05:21 MichaelDonovan wrote: Sup doods. I've been playing around with some logic lately. Kind of a fun little proof. Let me know what you think. I don't normally put formal logic stuff like this up here, but I figured I'd just see how it goes. Maybe you guys will appreciate this more than my prose type stuff. I dunno.
Some background information...
Classical free will is defined as "the ability to do otherwise." That is, if we have classical free will, then it means that when we do an action, it was possible that we could have made a different choice. For example, we could always just hold our breath and die instead of doing the action.
The classical free will thesis is just the thesis that says we have classical free will.
Hokay. So here it is:
Proof: The classical free will thesis is false.
If the classical free will thesis is correct, that is, if we have classical free will, then the following proposition is true:
Proposition (The classical definition of free will): If an agent did some action A, then it was possible for the agent to have done some contrary action B.
Definition: Two actions are contrary actions if an agent cannot perform both of them.
Contrapositive of the proposition: If it was not possible for the agent to have done B, then the agent did not do A.
We will attempt to disprove the proposition by showing that its logically equivalent contrapositive leads to a contradiction.
So we assume (for reductio) that it was not possible for the agent to have done B. If the proposition is true, then it should follow that the agent did not do A. We will show that this is not the case.
Let B* be the proposition that the agent performs action B, and let A* be the proposition that the agent performs action A.
Note that B is defined as an action contrary to A.
So by definition of B, we get the bi-conditional:
(1) B* <-> ~A*
This can be broken into the following:
(2) B* -> ~A* (3) ~A* -> B*
Recall that we have assumed that B is not possible. Since B is not possible, we deduce: (4) ~B*. Thus, (5) ~B* -> ~~A* by (3) Contraposition (6) ~B* -> A* by (4) Double Negative Elimination Therefore, (7) A* by (4)(6) Modus Ponens
Thus we have shown that if B was not possible, then the agent must have done A.
Therefore, it follows from our proposition:
(8) "If it was not possible for the agent to have done B, then the agent did not do A."
that it was possible for the agent to have done B. (By (7)(8) Modus Tollens)
Therefore we have the following contradiction: (P) It was not possible for the agent to have done B (assumed for reductio) (Q) It was possible for the agent to have done B (deduced from (P))
Since our proposition defending classical free will leads to a contradiction, the proposition must be false. Because the proposition is false, the classical free will thesis is thus false by Modus Tollens.
TL;DR of the following: for your reductio, you assume that the antecedent of the conditional is true. but the conditional can be true without the antecedent being true. if we assume, as we logically ought to, that our conditional as a whole is true, no contradiction follows. you have simply proven that the antecedent must be false (viz. that B could not be impossible)
let's fix your formalization somewhat: instead of using B, we'll just use ~A. we'll also introduce quantificational and modal symbols
so classical free will is: a -> ◇~a or more properly, since classical free will only says that some of our actions are freely willed: Ǝa (a -> ◇~a)
the contrapositive (for our assumed a) is now ~◇~a -> ~a or □a -> ~a
we can conclude a few things from this, but first let's run through your logical proof with our new symbols.
our assumption, in attempt of the reductio, is that ~a was not possible, or rather that □a.
from □a -> ~a we conclude both (this is trivially true) a ~a and obviously this is a contradiction.
well, what went wrong? this: in attempt to prove that your conditional led to a contradiction, you assumed that the antecedent was true. but we don't assume the truth of our antecedent in order to prove that our conditional was false. we assume that our conditional was true! and there are three ways for our conditional to be true. they are, as follows □a ^ ~a (which leads to a contradiction) ~□a ^ ~a ~□a ^ a
now our second set of truth values would lead to a contradiction, since we already assumed that a (we assumed there was some action such that we could have not done it). we are forced to conclude that ~□a ^ a. unfortunately for your proof, these two values do not lead to a contradiction.
On May 29 2014 08:20 micronesia wrote: It's unfortunate that I don't remember the mathematical rules of logic that well, but I don't see how you can use logic alone to prove the following:
It is not possible for every action to have at least one alternative, mutually exclusive action.
I don't think there are enough tools to work with. Putting technical lines of math aside, what is the reason why the above statement is true?
What you're getting at is the only non-formal assumption that I feel can be poked at in my proof.
My reasoning is as follows:
Recall that we are assuming for reductio that the classical free will thesis is true (we are then showing that a contradiction arises from this).
So since we are assuming classical free will exists, it would seem like no matter how pidgeon-holed into a line of action a person may seem to be, he always has the option of not doing that action, which is a contrary action in itself.
Here's why I say this:
Completing an action requires a break in inertia of sorts. That is, in order to execute an action, one must go from a state of inaction to a state of action and this requires some kind of effort, or at least a willing. If one does not will that the action be executed, they can choose not to act.
The way I think of it is like this: Imagine you are walking on a narrow path over an abyss. You cannot jump off the sides of the path because there is an invisible wall or something. And as you walk, the path behind you gets deleted such that you cannot go the other way. So it would seem as though you have only one choice, which is to continue walking forward. But it turns out that you still have the option of standing still.
I dunno. Maybe this is a weird example. But I think as long as we are assuming free will to exist (for reductio) we can assume that an action that you will should also have an alternative option if you were not to will it. It's easy to imagine a case were you are tide up with a sock in your mouth and you can't move, and say well, there seems to be no other option... But you have the option of willingly accepting your immobility or at least trying to escape (pointless as it may be). The action of accepting your captivity and the action of fighting it (regardless of the effectiveness of your struggle, which may be zero) are contrary actions.
Everything above seems to be an explanation supporting this classical free will thesis... following along using this plain-English approach, what is the contradiction?
The contradiction is probably something like this:
Taking a step forward is a sufficient condition for not having stood still. Not having stood still is a necessary condition for having stepped forward. Having stood still is a sufficient condition for not having stepped forward. Not having stepped forward is a necessary condition for having stood still.
So if I chose to step forward, this makes it the case that I did not choose to stand still. But not having chosen to stand still is the only way that it could have been possible to step forward. Thus, if you stepped forward, it must be the case that standing still was not possible.
Something like that.
Hm, when you put the 'contradiction' in plain English like this, it seems like your argument is teleological. As others have said, you are using your conclusion as evidence of your conclusion in a somewhat circular manner. Once again, I will not point to logical inaccuracies in your 'proof' as I do not have the necessarily knowledge to do so, but it seems a bit ridiculous to me to say:
"In order to choose an action, I had to not choose other actions, but it was necessary for me to not choose those other actions in order to choose the first action, so really I didn't have a choice," which is, in essence, what your contradiction is. It's almost a semantic argument rather than a logical one, when looked at in words rather than proofs.
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
That's because philosophers love to argue. Until the real scientist comes along and puts the matter to rest with empiric evidence instead of pure thought .
Facetiousness aside, you should really watch the video. Sam makes a compelling argument on why the very concept of free will doesn't really make sense.
Empirical evidence is hard to rely on when our sense perception is so limited
There are really two versions of the world: The world as we perceive it to be and the world as it actually is outside of our experience of it. Truth can be found in the world as it actually is. What we perceive is only contingent on the accuracy and completeness of our sense perception. The only way to get at the way the world actually is, it would seem, through rational thought and deductive reasoning. A fairly lofty task though, to be sure.
Empirical evidence is hard to rely on? Is that why science doesn't make any progress?
The best method that we have to find out truth about the world, an objective truth, is scientific method. Rational thought and deductive reasoning go out the window once we're confronted with something that doesn't seem rational, eg. quantum mechanics.
Well the problem is that empirical evidence isn't foolproof. We can only gather evidence from what we can sense. How do we know we're not in the matrix world, for example? We don't really know that do we? No amount of empirical evidence can prove that we aren't dreaming or that we aren't just brains in vats being stimulated with the illusion of experience. This is because any empirical evidence we gather is contingent upon our trust for our ability to sense it.
Quantum mechanics is not irrational necessarily. It just defies some our previous assumptions about the world. It renders many statements false that were once though to be true. That doesn't mean it's logically incoherent. It just means we don't understand it based on our current assumptions.
We can't disprove that we're not living in the matrix world. We can't disprove an infinite number of things. That's why we don't pay attention to things unless there's some evidence for them (well, except religion). It wouldn't be very reasonable to start thinking about things that we have no shred of evidence for (like if there's a teapot orbiting around Jupiter). Sure, you can lock yourself up in a room and try to use deductive reasoning all you want, but until you actually go outside of the room and look at what the world is telling you, you won't make any progress and in fact, most of your deductions will be simply wrong.
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
So the length of time by which we argue something determines how obvious it may or may not be?
Determines is a wrong word. Indicates is might be better. What I'm saying is that if the guy in this video actually came up with a solution so obvious that you couldn't argue with it, then I would have heard about it by now, and there would be nothing more to argue. But since people are still arguing, his solution can't be all that obvious.
I did write it became obvious to *me*. This was not a formal scientific theory that Sam proposed, but rather a compelling argument that "makes sense" once you think about it. There are people who challenges his argument though, like philosopher Dan Dennett, but from what I've read it doesn't look like a very good challenge.
Also, people are still arguing about creation vs evolution so you can't possibly take the length of the arguing as an indicator to one's side validity. Perhaps just watch the video or read about Sam's arguments on free will.
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
So the length of time by which we argue something determines how obvious it may or may not be?
Determines is a wrong word. Indicates is might be better. What I'm saying is that if the guy in this video actually came up with a solution so obvious that you couldn't argue with it, then I would have heard about it by now, and there would be nothing more to argue. But since people are still arguing, his solution can't be all that obvious.
Why is "determine" the wrong word? You're the one who said "If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years." which sounds fairly definitive. It also surprises me that you hadn't heard of Sam Harris. I think you should check out some of his debates or lectures, they're very entertaining at times.
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
So the length of time by which we argue something determines how obvious it may or may not be?
Determines is a wrong word. Indicates is might be better. What I'm saying is that if the guy in this video actually came up with a solution so obvious that you couldn't argue with it, then I would have heard about it by now, and there would be nothing more to argue. But since people are still arguing, his solution can't be all that obvious.
Why is "determine" the wrong word? You're the one who said "If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years." which sounds fairly definitive. It also surprises me that you hadn't heard of Sam Harris. I think you should check out some of his debates or lectures, they're very entertaining at times.
Sam Harris mainly deals with the kind of philosophy that I'm not interested in, so his name doesn't really come up.
On May 29 2014 08:39 Ghanburighan wrote: Interesting stuff, but here are a few issues:
a) You're using classical propositional logic to discuss possibilities, you'd need modal logic for a better representation. "Recall that we have assumed that B is not possible. Since B is not possible, we deduce: (4) ~B*." You can't do this formally without modal logic. And if you use modal logic, make sure you pick a system in which ~Diamond B* entails ~B*.
b) If you do adopt a modal logic, the original thesis would be better described as "at some point (world, time, etc.) where Diamond A holds, Diamond B holds as well."
c) I'm assuming you're utilizing material implication for "->" which has many known puzzles and problems. I don't think we can say much about free will or other concepts in a system in which B makes true A->B, i.e., where sitting in your office, makes true the statement: if you were blown up by a bomb this morning, then you're sitting in your office.
d) To attain (5) you make use of contraposition, but this rule doesn't correspond to our view of rational reasoning with probabilities. Consider Grice's Yog and Zog puzzle:
Yog and Zog are playing chess with special rules. Yog gets white 9/10 times and there are no draws. They have already played around 100 games, and Yog emerged victorious in 80 out of 90 of the games in which Yog had white, but Zog won all the remaining games. Now, the following two sentences have different probabilities.
a. If Yog had white, Yog won. b. If Yog lost, Yog had black.
The probability that the sentence (a) holds is 8/9 but it is only 1/2 for sentence (b). The problem with this situation is that (a) and (b) are equivalent if analyzed as material implication. This is because when you play chess, you use either the white or black pieces. So, playing with not white pieces is the same as playing with black pieces. And losing is the same as not winning when draws are taken out of the rules of chess. So if (a) is represented by p -> q then its contraposition ~q -> ~p is (b). But equivalent sentences should not have different probabilities, 8/9 and 1/2, respectively.
a) It is at this point in the proof where I am able to get rid of the need for any modal operators. I only need ~<>B* to show ~B*. And yes, I should have included that somewhere in my proof, but I am assuming that B being impossible entails that B* cannot be true.
b) Sure, I don't see any problem with saying it like that. Modal logic gets kind of messy though sometimes, so I wanted to try to do away with it.
c) This objection would be problematic if it were not for the fact that all of my statements in this arguments are based only on the logical structure of the proposition. That is, we don't really care if it makes sense empirically. What we're showing is that the classical free will thesis is logically incoherent. This doesn't say much about free will. It just says that the way the classical thesis is written leads to contradictions.
So, the fact that being blown up this morning makes it impossible for me to be sitting in my office isn't really important. If it were, we would include that statement in our argument, and the contradiction would be clear. I'm not sure if this a sufficient response to your objection though, so hammer it a bit more if you're dissatisfied.
d) That's a fun example. I'll have to think about that for a bit. But I don't think it's a problem for my argument because we either have free will or we don't. We either do action A or we do action not A. It's not like If you do action B, then you probably didn't do A. Or something like that. When you have mutually exclusive sets, the probability of their intersection is zero since their intersection is the empty set. I dunno if that addresses the problem completely, so again, hammer it some more if you're not satisfied.
On May 29 2014 08:39 Ghanburighan wrote: Interesting stuff, but here are a few issues:
a) You're using classical propositional logic to discuss possibilities, you'd need modal logic for a better representation. "Recall that we have assumed that B is not possible. Since B is not possible, we deduce: (4) ~B*." You can't do this formally without modal logic. And if you use modal logic, make sure you pick a system in which ~Diamond B* entails ~B*.
b) If you do adopt a modal logic, the original thesis would be better described as "at some point (world, time, etc.) where Diamond A holds, Diamond B holds as well."
c) I'm assuming you're utilizing material implication for "->" which has many known puzzles and problems. I don't think we can say much about free will or other concepts in a system in which B makes true A->B, i.e., where sitting in your office, makes true the statement: if you were blown up by a bomb this morning, then you're sitting in your office.
d) To attain (5) you make use of contraposition, but this rule doesn't correspond to our view of rational reasoning with probabilities. Consider Grice's Yog and Zog puzzle:
Yog and Zog are playing chess with special rules. Yog gets white 9/10 times and there are no draws. They have already played around 100 games, and Yog emerged victorious in 80 out of 90 of the games in which Yog had white, but Zog won all the remaining games. Now, the following two sentences have different probabilities.
a. If Yog had white, Yog won. b. If Yog lost, Yog had black.
The probability that the sentence (a) holds is 8/9 but it is only 1/2 for sentence (b). The problem with this situation is that (a) and (b) are equivalent if analyzed as material implication. This is because when you play chess, you use either the white or black pieces. So, playing with not white pieces is the same as playing with black pieces. And losing is the same as not winning when draws are taken out of the rules of chess. So if (a) is represented by p -> q then its contraposition ~q -> ~p is (b). But equivalent sentences should not have different probabilities, 8/9 and 1/2, respectively.
that example in d looks funny. so let's get everything straight. there are 80 games where Yog is white and Yog wins. there are 10 games where Yog is white and Yog loses. there are 10 games where Yog is black and Yog loses.
let's look at our conditionals and count up how many times they hold.
a. If Yog had white, Yog won. so there are 80 times when Yog had white and won. but our conditional is also (vacuously) true whenever Yog had black, whether he won or not (we might want to think about possible worlds instead of chess games following each other in time, but whatever). so there are 10 more times where our conditional is true, viz. the 10 times Yog is black and loses. so there are 90/100 times where this conditional is true, or 9/10.
b. If Yog lost, Yog had black. now there are 10 times where both of these are true. but the conditional is also (vacuously) true whenever the antecedent is false. and the antecendent is false exactly the number of times Yog wins - 80 times. so there are 90/100 times where this conditional is true, or 9/10.
our conditionals have equal possibility, so i don't see any contradiction. i'd have to read what grice actually wrote in order to deal with the problem more exactly, though. i anticipate that he either conflates material implication and probabilistic thinking or uses the distinction to deflate the problem.
On May 29 2014 08:20 micronesia wrote: It's unfortunate that I don't remember the mathematical rules of logic that well, but I don't see how you can use logic alone to prove the following:
It is not possible for every action to have at least one alternative, mutually exclusive action.
I don't think there are enough tools to work with. Putting technical lines of math aside, what is the reason why the above statement is true?
What you're getting at is the only non-formal assumption that I feel can be poked at in my proof.
My reasoning is as follows:
Recall that we are assuming for reductio that the classical free will thesis is true (we are then showing that a contradiction arises from this).
So since we are assuming classical free will exists, it would seem like no matter how pidgeon-holed into a line of action a person may seem to be, he always has the option of not doing that action, which is a contrary action in itself.
Here's why I say this:
Completing an action requires a break in inertia of sorts. That is, in order to execute an action, one must go from a state of inaction to a state of action and this requires some kind of effort, or at least a willing. If one does not will that the action be executed, they can choose not to act.
The way I think of it is like this: Imagine you are walking on a narrow path over an abyss. You cannot jump off the sides of the path because there is an invisible wall or something. And as you walk, the path behind you gets deleted such that you cannot go the other way. So it would seem as though you have only one choice, which is to continue walking forward. But it turns out that you still have the option of standing still.
I dunno. Maybe this is a weird example. But I think as long as we are assuming free will to exist (for reductio) we can assume that an action that you will should also have an alternative option if you were not to will it. It's easy to imagine a case were you are tide up with a sock in your mouth and you can't move, and say well, there seems to be no other option... But you have the option of willingly accepting your immobility or at least trying to escape (pointless as it may be). The action of accepting your captivity and the action of fighting it (regardless of the effectiveness of your struggle, which may be zero) are contrary actions.
Everything above seems to be an explanation supporting this classical free will thesis... following along using this plain-English approach, what is the contradiction?
The contradiction is probably something like this:
Taking a step forward is a sufficient condition for not having stood still. Not having stood still is a necessary condition for having stepped forward. Having stood still is a sufficient condition for not having stepped forward. Not having stepped forward is a necessary condition for having stood still.
So if I chose to step forward, this makes it the case that I did not choose to stand still. But not having chosen to stand still is the only way that it could have been possible to step forward. Thus, if you stepped forward, it must be the case that standing still was not possible.
Something like that.
Hm, when you put the 'contradiction' in plain English like this, it seems like your argument is teleological. As others have said, you are using your conclusion as evidence of your conclusion in a somewhat circular manner. Once again, I will not point to logical inaccuracies in your 'proof' as I do not have the necessarily knowledge to do so, but it seems a bit ridiculous to me to say:
"In order to choose an action, I had to not choose other actions, but it was necessary for me to not choose those other actions in order to choose the first action, so really I didn't have a choice," which is, in essence, what your contradiction is. It's almost a semantic argument rather than a logical one, when looked at in words rather than proofs.
Well... I'm not really satisfied with the way I worded it in plain English. It's kind of hard to say it properly because it's not all intuitive. Trying to explain why 1 + 1 = 2 in English without using formal logic to derive this truth from definitions leads to an explanation that won't really be satisfying and is probably full of holes. And I'm not sure I put the logic into words correctly there either...
Not having stepped forward is a necessary condition for having stood still. Was it possible for you to have stood still given that you stepped forward? No, because not having stepped forward is a necessary condition for having stood still. So given that you have stepped forward, it is impossible that you could have stood still.
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
That's because philosophers love to argue. Until the real scientist comes along and puts the matter to rest with empiric evidence instead of pure thought .
Facetiousness aside, you should really watch the video. Sam makes a compelling argument on why the very concept of free will doesn't really make sense.
Empirical evidence is hard to rely on when our sense perception is so limited
There are really two versions of the world: The world as we perceive it to be and the world as it actually is outside of our experience of it. Truth can be found in the world as it actually is. What we perceive is only contingent on the accuracy and completeness of our sense perception. The only way to get at the way the world actually is, it would seem, through rational thought and deductive reasoning. A fairly lofty task though, to be sure.
Empirical evidence is hard to rely on? Is that why science doesn't make any progress?
The best method that we have to find out truth about the world, an objective truth, is scientific method. Rational thought and deductive reasoning go out the window once we're confronted with something that doesn't seem rational, eg. quantum mechanics.
Well the problem is that empirical evidence isn't foolproof. We can only gather evidence from what we can sense. How do we know we're not in the matrix world, for example? We don't really know that do we? No amount of empirical evidence can prove that we aren't dreaming or that we aren't just brains in vats being stimulated with the illusion of experience. This is because any empirical evidence we gather is contingent upon our trust for our ability to sense it.
Quantum mechanics is not irrational necessarily. It just defies some our previous assumptions about the world. It renders many statements false that were once though to be true. That doesn't mean it's logically incoherent. It just means we don't understand it based on our current assumptions.
We can't disprove that we're not living in the matrix world. We can't disprove an infinite number of things. That's why we don't pay attention to things unless there's some evidence for them (well, except religion). It wouldn't be very reasonable to start thinking about things that we have no shred of evidence for (like if there's a teapot orbiting around Jupiter). Sure, you can lock yourself up in a room and try to use deductive reasoning all you want, but until you actually go outside of the room and look at what the world is telling you, you won't make any progress and in fact, most of your deductions will be simply wrong.
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
So the length of time by which we argue something determines how obvious it may or may not be?
Determines is a wrong word. Indicates is might be better. What I'm saying is that if the guy in this video actually came up with a solution so obvious that you couldn't argue with it, then I would have heard about it by now, and there would be nothing more to argue. But since people are still arguing, his solution can't be all that obvious.
I did write it became obvious to *me*. This was not a formal scientific theory that Sam proposed, but rather a compelling argument that "makes sense" once you think about it. There are people who challenges his argument though, like philosopher Dan Dennett, but from what I've read it doesn't look like a very good challenge.
Also, people are still arguing about creation vs evolution so you can't possibly take the length of the arguing as an indicator to one's side validity. Perhaps just watch the video or read about Sam's arguments on free will.
I'm not saying that empirical endeavors are pointless. I'm just saying that you can't really value empirical evidence too highly and trust it too much.
And the only way of getting past the limits of our sense perception is probably to use logical deductions. You can't just go by empirical evidence for answers to your questions because your evidence is so very limited. That's not to say that logic alone can answer all your questions. Logic is merely a formal way of thinking. You have to fill the propositions with empirical assumptions on your own. And then any truth you derive is contingent upon those assumptions, which are contingent upon your sense perception.
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
That's because philosophers love to argue. Until the real scientist comes along and puts the matter to rest with empiric evidence instead of pure thought .
Facetiousness aside, you should really watch the video. Sam makes a compelling argument on why the very concept of free will doesn't really make sense.
Empirical evidence is hard to rely on when our sense perception is so limited
There are really two versions of the world: The world as we perceive it to be and the world as it actually is outside of our experience of it. Truth can be found in the world as it actually is. What we perceive is only contingent on the accuracy and completeness of our sense perception. The only way to get at the way the world actually is, it would seem, through rational thought and deductive reasoning. A fairly lofty task though, to be sure.
Empirical evidence is hard to rely on? Is that why science doesn't make any progress?
The best method that we have to find out truth about the world, an objective truth, is scientific method. Rational thought and deductive reasoning go out the window once we're confronted with something that doesn't seem rational, eg. quantum mechanics.
Well the problem is that empirical evidence isn't foolproof. We can only gather evidence from what we can sense. How do we know we're not in the matrix world, for example? We don't really know that do we? No amount of empirical evidence can prove that we aren't dreaming or that we aren't just brains in vats being stimulated with the illusion of experience. This is because any empirical evidence we gather is contingent upon our trust for our ability to sense it.
Quantum mechanics is not irrational necessarily. It just defies some our previous assumptions about the world. It renders many statements false that were once though to be true. That doesn't mean it's logically incoherent. It just means we don't understand it based on our current assumptions.
We can't disprove that we're not living in the matrix world. We can't disprove an infinite number of things. That's why we don't pay attention to things unless there's some evidence for them (well, except religion). It wouldn't be very reasonable to start thinking about things that we have no shred of evidence for (like if there's a teapot orbiting around Jupiter). Sure, you can lock yourself up in a room and try to use deductive reasoning all you want, but until you actually go outside of the room and look at what the world is telling you, you won't make any progress and in fact, most of your deductions will be simply wrong.
On May 29 2014 08:38 MichaelDonovan wrote:
On May 29 2014 08:36 ninazerg wrote:
On May 29 2014 07:14 MichaelDonovan wrote:
On May 29 2014 07:09 2Pacalypse- wrote: A good video on free will by Sam Harris that made it painfully obvious (to me) that free will is an illusion:
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
So the length of time by which we argue something determines how obvious it may or may not be?
Determines is a wrong word. Indicates is might be better. What I'm saying is that if the guy in this video actually came up with a solution so obvious that you couldn't argue with it, then I would have heard about it by now, and there would be nothing more to argue. But since people are still arguing, his solution can't be all that obvious.
I did write it became obvious to *me*. This was not a formal scientific theory that Sam proposed, but rather a compelling argument that "makes sense" once you think about it. There are people who challenges his argument though, like philosopher Dan Dennett, but from what I've read it doesn't look like a very good challenge.
Also, people are still arguing about creation vs evolution so you can't possibly take the length of the arguing as an indicator to one's side validity. Perhaps just watch the video or read about Sam's arguments on free will.
I'm not saying that empirical endeavors are pointless. I'm just saying that you can't really value empirical evidence too highly and trust it too much.
And the only way of getting past the limits of our sense perception is probably to use logical deductions. You can't just go by empirical evidence for answers to your questions because your evidence is so very limited. That's not to say that logic alone can answer all your questions. Logic is merely a formal way of thinking. You have to fill the propositions with empirical assumptions on your own. And then any truth you derive is contingent upon those assumptions, which are contingent upon your sense perception.
And that's what scientific method is: rational thinking applied to empiric evidence.
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
That's because philosophers love to argue. Until the real scientist comes along and puts the matter to rest with empiric evidence instead of pure thought .
Facetiousness aside, you should really watch the video. Sam makes a compelling argument on why the very concept of free will doesn't really make sense.
Empirical evidence is hard to rely on when our sense perception is so limited
There are really two versions of the world: The world as we perceive it to be and the world as it actually is outside of our experience of it. Truth can be found in the world as it actually is. What we perceive is only contingent on the accuracy and completeness of our sense perception. The only way to get at the way the world actually is, it would seem, through rational thought and deductive reasoning. A fairly lofty task though, to be sure.
Empirical evidence is hard to rely on? Is that why science doesn't make any progress?
The best method that we have to find out truth about the world, an objective truth, is scientific method. Rational thought and deductive reasoning go out the window once we're confronted with something that doesn't seem rational, eg. quantum mechanics.
Well the problem is that empirical evidence isn't foolproof. We can only gather evidence from what we can sense. How do we know we're not in the matrix world, for example? We don't really know that do we? No amount of empirical evidence can prove that we aren't dreaming or that we aren't just brains in vats being stimulated with the illusion of experience. This is because any empirical evidence we gather is contingent upon our trust for our ability to sense it.
Quantum mechanics is not irrational necessarily. It just defies some our previous assumptions about the world. It renders many statements false that were once though to be true. That doesn't mean it's logically incoherent. It just means we don't understand it based on our current assumptions.
We can't disprove that we're not living in the matrix world. We can't disprove an infinite number of things. That's why we don't pay attention to things unless there's some evidence for them (well, except religion). It wouldn't be very reasonable to start thinking about things that we have no shred of evidence for (like if there's a teapot orbiting around Jupiter). Sure, you can lock yourself up in a room and try to use deductive reasoning all you want, but until you actually go outside of the room and look at what the world is telling you, you won't make any progress and in fact, most of your deductions will be simply wrong.
On May 29 2014 08:38 MichaelDonovan wrote:
On May 29 2014 08:36 ninazerg wrote:
On May 29 2014 07:14 MichaelDonovan wrote:
On May 29 2014 07:09 2Pacalypse- wrote: A good video on free will by Sam Harris that made it painfully obvious (to me) that free will is an illusion:
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
So the length of time by which we argue something determines how obvious it may or may not be?
Determines is a wrong word. Indicates is might be better. What I'm saying is that if the guy in this video actually came up with a solution so obvious that you couldn't argue with it, then I would have heard about it by now, and there would be nothing more to argue. But since people are still arguing, his solution can't be all that obvious.
I did write it became obvious to *me*. This was not a formal scientific theory that Sam proposed, but rather a compelling argument that "makes sense" once you think about it. There are people who challenges his argument though, like philosopher Dan Dennett, but from what I've read it doesn't look like a very good challenge.
Also, people are still arguing about creation vs evolution so you can't possibly take the length of the arguing as an indicator to one's side validity. Perhaps just watch the video or read about Sam's arguments on free will.
I'm not saying that empirical endeavors are pointless. I'm just saying that you can't really value empirical evidence too highly and trust it too much.
And the only way of getting past the limits of our sense perception is probably to use logical deductions. You can't just go by empirical evidence for answers to your questions because your evidence is so very limited. That's not to say that logic alone can answer all your questions. Logic is merely a formal way of thinking. You have to fill the propositions with empirical assumptions on your own. And then any truth you derive is contingent upon those assumptions, which are contingent upon your sense perception.
And that's what scientific method is: rational thinking applied to empiric evidence.
Right, but the difference is that if empirical evidence suggests something that logic denies, then we conclude that our sense perception misled us. But if logic implies something that empirical evidence seems to deny, then we again conclude that our sense perception is wrong.
What I'm saying is that sense perception and empirical evidence are always the first suspects for error. Logic is more trustworthy.
On May 29 2014 05:21 MichaelDonovan wrote: Sup doods. I've been playing around with some logic lately. Kind of a fun little proof. Let me know what you think. I don't normally put formal logic stuff like this up here, but I figured I'd just see how it goes. Maybe you guys will appreciate this more than my prose type stuff. I dunno.
Some background information...
Classical free will is defined as "the ability to do otherwise." That is, if we have classical free will, then it means that when we do an action, it was possible that we could have made a different choice. For example, we could always just hold our breath and die instead of doing the action.
The classical free will thesis is just the thesis that says we have classical free will.
Hokay. So here it is:
Proof: The classical free will thesis is false.
If the classical free will thesis is correct, that is, if we have classical free will, then the following proposition is true:
Proposition (The classical definition of free will): If an agent did some action A, then it was possible for the agent to have done some contrary action B.
Definition: Two actions are contrary actions if an agent cannot perform both of them.
Contrapositive of the proposition: If it was not possible for the agent to have done B, then the agent did not do A.
We will attempt to disprove the proposition by showing that its logically equivalent contrapositive leads to a contradiction.
So we assume (for reductio) that it was not possible for the agent to have done B. If the proposition is true, then it should follow that the agent did not do A. We will show that this is not the case.
Let B* be the proposition that the agent performs action B, and let A* be the proposition that the agent performs action A.
Note that B is defined as an action contrary to A.
So by definition of B, we get the bi-conditional:
(1) B* <-> ~A*
This can be broken into the following:
(2) B* -> ~A* (3) ~A* -> B*
Recall that we have assumed that B is not possible. Since B is not possible, we deduce: (4) ~B*. Thus, (5) ~B* -> ~~A* by (3) Contraposition (6) ~B* -> A* by (4) Double Negative Elimination Therefore, (7) A* by (4)(6) Modus Ponens
Thus we have shown that if B was not possible, then the agent must have done A.
Therefore, it follows from our proposition:
(8) "If it was not possible for the agent to have done B, then the agent did not do A."
that it was possible for the agent to have done B. (By (7)(8) Modus Tollens)
Therefore we have the following contradiction: (P) It was not possible for the agent to have done B (assumed for reductio) (Q) It was possible for the agent to have done B (deduced from (P))
Since our proposition defending classical free will leads to a contradiction, the proposition must be false. Because the proposition is false, the classical free will thesis is thus false by Modus Tollens.
TL;DR of the following: for your reductio, you assume that the antecedent of the conditional is true. but the conditional can be true without the antecedent being true. if we assume, as we logically ought to, that our conditional as a whole is true, no contradiction follows. you have simply proven that the antecedent must be false (viz. that B could not be impossible)
let's fix your formalization somewhat: instead of using B, we'll just use ~A. we'll also introduce quantificational and modal symbols
so classical free will is: a -> ◇~a or more properly, since classical free will only says that some of our actions are freely willed: Ǝa (a -> ◇~a)
the contrapositive (for our assumed a) is now ~◇~a -> ~a or □a -> ~a
we can conclude a few things from this, but first let's run through your logical proof with our new symbols.
our assumption, in attempt of the reductio, is that ~a was not possible, or rather that □a.
from □a -> ~a we conclude both (this is trivially true) a ~a and obviously this is a contradiction.
well, what went wrong? this: in attempt to prove that your conditional led to a contradiction, you assumed that the antecedent was true. but we don't assume the truth of our antecedent in order to prove that our conditional was false. we assume that our conditional was true! and there are three ways for our conditional to be true. they are, as follows □a ^ ~a (which leads to a contradiction) ~□a ^ ~a ~□a ^ a
now our second set of truth values would lead to a contradiction, since we already assumed that a (we assumed there was some action such that we could have not done it). we are forced to conclude that ~□a ^ a. unfortunately for your proof, these two values do not lead to a contradiction.
I'm not really sure where to start with this. I feel like you've probably got me here, but this requires more thought.
I think what I want to point to is something like this:
We assume for reductio that ~<>B -> ~A*. (recall A* is the proposition that the agent performs A.)
~<>B -> ~B* (we'll just assume this).
so ~B* -> ~A*.
So we have assumed ~B* -> ~A* But we come up with ~B* -> A*
This is a contradiction, so our assumed conditional (in its entirety) is false.
Does that make more sense? Or am I still screwing up?
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
That's because philosophers love to argue. Until the real scientist comes along and puts the matter to rest with empiric evidence instead of pure thought .
Facetiousness aside, you should really watch the video. Sam makes a compelling argument on why the very concept of free will doesn't really make sense.
Empirical evidence is hard to rely on when our sense perception is so limited
There are really two versions of the world: The world as we perceive it to be and the world as it actually is outside of our experience of it. Truth can be found in the world as it actually is. What we perceive is only contingent on the accuracy and completeness of our sense perception. The only way to get at the way the world actually is, it would seem, through rational thought and deductive reasoning. A fairly lofty task though, to be sure.
Empirical evidence is hard to rely on? Is that why science doesn't make any progress?
The best method that we have to find out truth about the world, an objective truth, is scientific method. Rational thought and deductive reasoning go out the window once we're confronted with something that doesn't seem rational, eg. quantum mechanics.
Well the problem is that empirical evidence isn't foolproof. We can only gather evidence from what we can sense. How do we know we're not in the matrix world, for example? We don't really know that do we? No amount of empirical evidence can prove that we aren't dreaming or that we aren't just brains in vats being stimulated with the illusion of experience. This is because any empirical evidence we gather is contingent upon our trust for our ability to sense it.
Quantum mechanics is not irrational necessarily. It just defies some our previous assumptions about the world. It renders many statements false that were once though to be true. That doesn't mean it's logically incoherent. It just means we don't understand it based on our current assumptions.
We can't disprove that we're not living in the matrix world. We can't disprove an infinite number of things. That's why we don't pay attention to things unless there's some evidence for them (well, except religion). It wouldn't be very reasonable to start thinking about things that we have no shred of evidence for (like if there's a teapot orbiting around Jupiter). Sure, you can lock yourself up in a room and try to use deductive reasoning all you want, but until you actually go outside of the room and look at what the world is telling you, you won't make any progress and in fact, most of your deductions will be simply wrong.
On May 29 2014 08:38 MichaelDonovan wrote:
On May 29 2014 08:36 ninazerg wrote:
On May 29 2014 07:14 MichaelDonovan wrote:
On May 29 2014 07:09 2Pacalypse- wrote: A good video on free will by Sam Harris that made it painfully obvious (to me) that free will is an illusion:
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
So the length of time by which we argue something determines how obvious it may or may not be?
Determines is a wrong word. Indicates is might be better. What I'm saying is that if the guy in this video actually came up with a solution so obvious that you couldn't argue with it, then I would have heard about it by now, and there would be nothing more to argue. But since people are still arguing, his solution can't be all that obvious.
I did write it became obvious to *me*. This was not a formal scientific theory that Sam proposed, but rather a compelling argument that "makes sense" once you think about it. There are people who challenges his argument though, like philosopher Dan Dennett, but from what I've read it doesn't look like a very good challenge.
Also, people are still arguing about creation vs evolution so you can't possibly take the length of the arguing as an indicator to one's side validity. Perhaps just watch the video or read about Sam's arguments on free will.
I'm not saying that empirical endeavors are pointless. I'm just saying that you can't really value empirical evidence too highly and trust it too much.
And the only way of getting past the limits of our sense perception is probably to use logical deductions. You can't just go by empirical evidence for answers to your questions because your evidence is so very limited. That's not to say that logic alone can answer all your questions. Logic is merely a formal way of thinking. You have to fill the propositions with empirical assumptions on your own. And then any truth you derive is contingent upon those assumptions, which are contingent upon your sense perception.
And that's what scientific method is: rational thinking applied to empiric evidence.
Right, but the difference is that if empirical evidence suggests something that logic denies, then we conclude that our sense perception misled us. But if logic implies something that empirical evidence seems to deny, then what do we again conclude that our sense perception is wrong.
What I'm saying is that sense perception and empirical evidence are always the first suspects for error. Logic is more trustworthy.
Uhm, no, it's the other way around.
When we demonstrated with empirical evidence that the electron can be at the two places at once, something that seems logically impossible, we didn't dismiss it due to our sense perception misleading us.
Sure, you can try to "update" logic to fit with the reality, but you can't update reality to fit with your logic.
On May 29 2014 10:21 teddyoojo wrote: havent read all posts so im not sure if it has come up yet but i absolutely love this (a little paraphrased) quote by shopenhauer:
You can do what you want, but you cannot want what you want
Haha yeah that's funny.
There is this idea out there called the "deep self view" which is applied to moral responsibility.
It's something like,
I want to do action A. But I don't want to want to do action A. So I'm not morally responsible for doing A.
But if I want to want to want to want to etc... do action A, then I'm morally responsible. Or something like that.
So like, Fred wants to smoke a cigarette really badly. But he doesn't want to want to smoke a cigarette since he's trying to quit smoking. So he's not morally responsible for smoking the cigarette because his desires didn't line up. I don't know if I'm doing this justice, though since I didn't really pay much attention to it when I read about it. It seems like a silly position to hold to me.
On May 29 2014 07:14 MichaelDonovan wrote: [quote]
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
That's because philosophers love to argue. Until the real scientist comes along and puts the matter to rest with empiric evidence instead of pure thought .
Facetiousness aside, you should really watch the video. Sam makes a compelling argument on why the very concept of free will doesn't really make sense.
Empirical evidence is hard to rely on when our sense perception is so limited
There are really two versions of the world: The world as we perceive it to be and the world as it actually is outside of our experience of it. Truth can be found in the world as it actually is. What we perceive is only contingent on the accuracy and completeness of our sense perception. The only way to get at the way the world actually is, it would seem, through rational thought and deductive reasoning. A fairly lofty task though, to be sure.
Empirical evidence is hard to rely on? Is that why science doesn't make any progress?
The best method that we have to find out truth about the world, an objective truth, is scientific method. Rational thought and deductive reasoning go out the window once we're confronted with something that doesn't seem rational, eg. quantum mechanics.
Well the problem is that empirical evidence isn't foolproof. We can only gather evidence from what we can sense. How do we know we're not in the matrix world, for example? We don't really know that do we? No amount of empirical evidence can prove that we aren't dreaming or that we aren't just brains in vats being stimulated with the illusion of experience. This is because any empirical evidence we gather is contingent upon our trust for our ability to sense it.
Quantum mechanics is not irrational necessarily. It just defies some our previous assumptions about the world. It renders many statements false that were once though to be true. That doesn't mean it's logically incoherent. It just means we don't understand it based on our current assumptions.
We can't disprove that we're not living in the matrix world. We can't disprove an infinite number of things. That's why we don't pay attention to things unless there's some evidence for them (well, except religion). It wouldn't be very reasonable to start thinking about things that we have no shred of evidence for (like if there's a teapot orbiting around Jupiter). Sure, you can lock yourself up in a room and try to use deductive reasoning all you want, but until you actually go outside of the room and look at what the world is telling you, you won't make any progress and in fact, most of your deductions will be simply wrong.
On May 29 2014 08:38 MichaelDonovan wrote:
On May 29 2014 08:36 ninazerg wrote:
On May 29 2014 07:14 MichaelDonovan wrote:
On May 29 2014 07:09 2Pacalypse- wrote: A good video on free will by Sam Harris that made it painfully obvious (to me) that free will is an illusion:
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
So the length of time by which we argue something determines how obvious it may or may not be?
Determines is a wrong word. Indicates is might be better. What I'm saying is that if the guy in this video actually came up with a solution so obvious that you couldn't argue with it, then I would have heard about it by now, and there would be nothing more to argue. But since people are still arguing, his solution can't be all that obvious.
I did write it became obvious to *me*. This was not a formal scientific theory that Sam proposed, but rather a compelling argument that "makes sense" once you think about it. There are people who challenges his argument though, like philosopher Dan Dennett, but from what I've read it doesn't look like a very good challenge.
Also, people are still arguing about creation vs evolution so you can't possibly take the length of the arguing as an indicator to one's side validity. Perhaps just watch the video or read about Sam's arguments on free will.
I'm not saying that empirical endeavors are pointless. I'm just saying that you can't really value empirical evidence too highly and trust it too much.
And the only way of getting past the limits of our sense perception is probably to use logical deductions. You can't just go by empirical evidence for answers to your questions because your evidence is so very limited. That's not to say that logic alone can answer all your questions. Logic is merely a formal way of thinking. You have to fill the propositions with empirical assumptions on your own. And then any truth you derive is contingent upon those assumptions, which are contingent upon your sense perception.
And that's what scientific method is: rational thinking applied to empiric evidence.
Right, but the difference is that if empirical evidence suggests something that logic denies, then we conclude that our sense perception misled us. But if logic implies something that empirical evidence seems to deny, then what do we again conclude that our sense perception is wrong.
What I'm saying is that sense perception and empirical evidence are always the first suspects for error. Logic is more trustworthy.
Uhm, no, it's the other way around.
When we demonstrated with empirical evidence that the electron can be at the two places at once, something that seems logically impossible, we didn't dismiss it due to our sense perception misleading us.
Sure, you can try to "update" logic to fit with the reality, but you can't update reality to fit with your logic.
Theres actually some debate about that electron business. I mean, all the Heisenberg uncertainty principle really says is:
At the instant of time when the position is determined, that is, at the instant when the photon is scattered by the electron, the electron undergoes a discontinuous change in momentum. This change is the greater the smaller the wavelength of the light employed, i.e., the more exact the determination of the position. At the instant at which the position of the electron is known, its momentum therefore can be known only up to magnitudes which correspond to that discontinuous change; thus, the more precisely the position is determined, the less precisely the momentum is known, and conversely
This is just a statement about what we can know. In other words, it seems like a purely epistemological statement saying that we can't measure both values at the same time. It doesn't necessarily mean that the electron does not have both momentum and position values. It just says we can't measure them. So I dunno. It's not like everyone agrees on this stuff.
What I'm saying though is that absolute modality trumps natural modality.
Like, logic tells you that you can't both lick the back of your hand and not lick the back of your hand at the same time. Empirically, you will never ever ever be able to do this and give evidence against what was logically derived.
Ultimately it has been mathematical logic that has come up with the kind of theorems which cause us to throw out what we thought we already knew. edit: in history, i mean
On May 29 2014 05:21 MichaelDonovan wrote: Sup doods. I've been playing around with some logic lately. Kind of a fun little proof. Let me know what you think. I don't normally put formal logic stuff like this up here, but I figured I'd just see how it goes. Maybe you guys will appreciate this more than my prose type stuff. I dunno.
Some background information...
Classical free will is defined as "the ability to do otherwise." That is, if we have classical free will, then it means that when we do an action, it was possible that we could have made a different choice. For example, we could always just hold our breath and die instead of doing the action.
The classical free will thesis is just the thesis that says we have classical free will.
Hokay. So here it is:
Proof: The classical free will thesis is false.
If the classical free will thesis is correct, that is, if we have classical free will, then the following proposition is true:
Proposition (The classical definition of free will): If an agent did some action A, then it was possible for the agent to have done some contrary action B.
Definition: Two actions are contrary actions if an agent cannot perform both of them.
Contrapositive of the proposition: If it was not possible for the agent to have done B, then the agent did not do A.
We will attempt to disprove the proposition by showing that its logically equivalent contrapositive leads to a contradiction.
So we assume (for reductio) that it was not possible for the agent to have done B. If the proposition is true, then it should follow that the agent did not do A. We will show that this is not the case.
Let B* be the proposition that the agent performs action B, and let A* be the proposition that the agent performs action A.
Note that B is defined as an action contrary to A.
So by definition of B, we get the bi-conditional:
(1) B* <-> ~A*
This can be broken into the following:
(2) B* -> ~A* (3) ~A* -> B*
Recall that we have assumed that B is not possible. Since B is not possible, we deduce: (4) ~B*. Thus, (5) ~B* -> ~~A* by (3) Contraposition (6) ~B* -> A* by (4) Double Negative Elimination Therefore, (7) A* by (4)(6) Modus Ponens
Thus we have shown that if B was not possible, then the agent must have done A.
Therefore, it follows from our proposition:
(8) "If it was not possible for the agent to have done B, then the agent did not do A."
that it was possible for the agent to have done B. (By (7)(8) Modus Tollens)
Therefore we have the following contradiction: (P) It was not possible for the agent to have done B (assumed for reductio) (Q) It was possible for the agent to have done B (deduced from (P))
Since our proposition defending classical free will leads to a contradiction, the proposition must be false. Because the proposition is false, the classical free will thesis is thus false by Modus Tollens.
TL;DR of the following: for your reductio, you assume that the antecedent of the conditional is true. but the conditional can be true without the antecedent being true. if we assume, as we logically ought to, that our conditional as a whole is true, no contradiction follows. you have simply proven that the antecedent must be false (viz. that B could not be impossible)
let's fix your formalization somewhat: instead of using B, we'll just use ~A. we'll also introduce quantificational and modal symbols
so classical free will is: a -> ◇~a or more properly, since classical free will only says that some of our actions are freely willed: Ǝa (a -> ◇~a)
the contrapositive (for our assumed a) is now ~◇~a -> ~a or □a -> ~a
we can conclude a few things from this, but first let's run through your logical proof with our new symbols.
our assumption, in attempt of the reductio, is that ~a was not possible, or rather that □a.
from □a -> ~a we conclude both (this is trivially true) a ~a and obviously this is a contradiction.
well, what went wrong? this: in attempt to prove that your conditional led to a contradiction, you assumed that the antecedent was true. but we don't assume the truth of our antecedent in order to prove that our conditional was false. we assume that our conditional was true! and there are three ways for our conditional to be true. they are, as follows □a ^ ~a (which leads to a contradiction) ~□a ^ ~a ~□a ^ a
now our second set of truth values would lead to a contradiction, since we already assumed that a (we assumed there was some action such that we could have not done it). we are forced to conclude that ~□a ^ a. unfortunately for your proof, these two values do not lead to a contradiction.
I'm not really sure where to start with this. I feel like you've probably got me here, but this requires more thought.
I think what I want to point to is something like this:
We assume for reductio that ~<>B -> ~A*. (recall A* is the proposition that the agent performs A.)
~<>B -> ~B* (we'll just assume this).
so ~B* -> ~A*.
So we have assumed ~B* -> ~A* But we come up with ~B* -> A*
This is a contradiction, so our assumed conditional (in its entirety) is false.
Does that make more sense? Or am I still screwing up?
Let's again convert into my preferred symbolization. We assume for reductio, again, ~◇~A -> ~A. Now, apparently, we're going to assume ~◇~A -> A (we don't need to assume it, since it's self-evident). From this, you conclude A -> ~A (you wrote it as ~B* -> ~A*). I don't know how you reach this conclusion. Anyway, let's move on. You produce the two conditionals A -> ~A and A -> A. I don't know where you produce these two conditionals, but note that they are not contradictory. They are both true when ~A. Now you might conclude that we have nonetheless concluded that ~A must be the case, but your logic was flawed in reaching this conclusion, so we aren't forced to conclude that.
Your step in
~<>B -> ~B* (we'll just assume this).
so ~B* -> ~A*.
I would write as ~◇~A -> A moving to A -> ~A but I do not see how this follows.. Either □A ^ A, in which case the latter conditional is false, or ~□A ^ (A v ~A), in which case the latter conditional does not follow.
I don't know if you've understood my point better now, but here's a simple exercise. Take the truth values ~□A and A and see whether they produce a contradiction when we have ƎA (A -> ◇~A) and ~◇~A -> ~A (I'm not formalizing properly here but whatever). You produce a reductio by assuming □A (you write this as "assuming B is not possible"), but we need not assume □A in order for the premises that translate to the classical free will thesis to be true.
I think that if you 1) stick with proper formalization and 2) consider why your reductio won't work for the initial free will thesis (not its contrapositive) you'll see why your proof is not valid. Again, in assuming our contrapositive to be true, we do not need to assume that the antecedent is true. And it is obvious why a free will thesis-ist is not going to say the antecedent is true: it would directly follow from □A that ~◇~A, which is exactly the negation of the free will thesis.
I'll try to formalize this properly, just for my own edification.
We'll only quantify over actions, to simplify a little. P = "is performed by a human" Free will thesis = Ǝx (Px ^ (Px -> ◇~Px) We'll assume f is such an action. It follows that: Pf ^ (Pf -> ◇~Pf) And therefore ◇~Pf Now it's also true that ~◇~Pf -> ~Pf and □Pf -> ~Pf For your reductio, we assume that this statement is true. There are three ways for it to be true. We'll run through all possibilities to see if any are consistent. 1. □Pf ^ ~Pf Clearly false. We already have Pf, so we cannot also have ~Pf.
2. ~□Pf ^ ~Pf Same as 1.
3. ~□Pf ^ Pf ~□Pf -> ◇~Pf ◇~Pf ◇~Pf ^ Pf I see no way to produce a contradiction from these truth values. Do you? Recall that our existing premises amount to: Ǝx (Px ^ (Px -> ◇~Px) Pf ^ (Pf -> ◇~Pf) ~◇~Pf -> ~Pf Each of these statements seems to come out true when we assume ~□Pf ^ Pf.
On May 29 2014 05:21 MichaelDonovan wrote: Sup doods. I've been playing around with some logic lately. Kind of a fun little proof. Let me know what you think. I don't normally put formal logic stuff like this up here, but I figured I'd just see how it goes. Maybe you guys will appreciate this more than my prose type stuff. I dunno.
Some background information...
Classical free will is defined as "the ability to do otherwise." That is, if we have classical free will, then it means that when we do an action, it was possible that we could have made a different choice. For example, we could always just hold our breath and die instead of doing the action.
The classical free will thesis is just the thesis that says we have classical free will.
Hokay. So here it is:
Proof: The classical free will thesis is false.
If the classical free will thesis is correct, that is, if we have classical free will, then the following proposition is true:
Proposition (The classical definition of free will): If an agent did some action A, then it was possible for the agent to have done some contrary action B.
Definition: Two actions are contrary actions if an agent cannot perform both of them.
Contrapositive of the proposition: If it was not possible for the agent to have done B, then the agent did not do A.
We will attempt to disprove the proposition by showing that its logically equivalent contrapositive leads to a contradiction.
So we assume (for reductio) that it was not possible for the agent to have done B. If the proposition is true, then it should follow that the agent did not do A. We will show that this is not the case.
Let B* be the proposition that the agent performs action B, and let A* be the proposition that the agent performs action A.
Note that B is defined as an action contrary to A.
So by definition of B, we get the bi-conditional:
(1) B* <-> ~A*
This can be broken into the following:
(2) B* -> ~A* (3) ~A* -> B*
Recall that we have assumed that B is not possible. Since B is not possible, we deduce: (4) ~B*. Thus, (5) ~B* -> ~~A* by (3) Contraposition (6) ~B* -> A* by (4) Double Negative Elimination Therefore, (7) A* by (4)(6) Modus Ponens
Thus we have shown that if B was not possible, then the agent must have done A.
Therefore, it follows from our proposition:
(8) "If it was not possible for the agent to have done B, then the agent did not do A."
that it was possible for the agent to have done B. (By (7)(8) Modus Tollens)
Therefore we have the following contradiction: (P) It was not possible for the agent to have done B (assumed for reductio) (Q) It was possible for the agent to have done B (deduced from (P))
Since our proposition defending classical free will leads to a contradiction, the proposition must be false. Because the proposition is false, the classical free will thesis is thus false by Modus Tollens.
TL;DR of the following: for your reductio, you assume that the antecedent of the conditional is true. but the conditional can be true without the antecedent being true. if we assume, as we logically ought to, that our conditional as a whole is true, no contradiction follows. you have simply proven that the antecedent must be false (viz. that B could not be impossible)
let's fix your formalization somewhat: instead of using B, we'll just use ~A. we'll also introduce quantificational and modal symbols
so classical free will is: a -> ◇~a or more properly, since classical free will only says that some of our actions are freely willed: Ǝa (a -> ◇~a)
the contrapositive (for our assumed a) is now ~◇~a -> ~a or □a -> ~a
we can conclude a few things from this, but first let's run through your logical proof with our new symbols.
our assumption, in attempt of the reductio, is that ~a was not possible, or rather that □a.
from □a -> ~a we conclude both (this is trivially true) a ~a and obviously this is a contradiction.
well, what went wrong? this: in attempt to prove that your conditional led to a contradiction, you assumed that the antecedent was true. but we don't assume the truth of our antecedent in order to prove that our conditional was false. we assume that our conditional was true! and there are three ways for our conditional to be true. they are, as follows □a ^ ~a (which leads to a contradiction) ~□a ^ ~a ~□a ^ a
now our second set of truth values would lead to a contradiction, since we already assumed that a (we assumed there was some action such that we could have not done it). we are forced to conclude that ~□a ^ a. unfortunately for your proof, these two values do not lead to a contradiction.
I'm not really sure where to start with this. I feel like you've probably got me here, but this requires more thought.
I think what I want to point to is something like this:
We assume for reductio that ~<>B -> ~A*. (recall A* is the proposition that the agent performs A.)
~<>B -> ~B* (we'll just assume this).
so ~B* -> ~A*.
So we have assumed ~B* -> ~A* But we come up with ~B* -> A*
This is a contradiction, so our assumed conditional (in its entirety) is false.
Does that make more sense? Or am I still screwing up?
Let's again convert into my preferred symbolization. We assume for reductio, again, ~◇~A -> ~A. Now, apparently, we're going to assume ~◇~A -> A (we don't need to assume it, since it's self-evident). From this, you conclude A -> ~A (you wrote it as ~B* -> ~A*). I don't know how you reach this conclusion. Anyway, let's move on. You produce the two conditionals A -> ~A and A -> A. I don't know where you produce these two conditionals, but note that they are not contradictory. They are both true when ~A. Now you might conclude that we have nonetheless concluded that ~A must be the case, but your logic was flawed in reaching this conclusion, so we aren't forced to conclude that.
I would write as ~◇~A -> A moving to A -> ~A but I do not see how this follows.. Either □A ^ A, in which case the latter conditional is false, or ~□A ^ (A v ~A), in which case the latter conditional does not follow.
I don't know if you've understood my point better now, but here's a simple exercise. Take the truth values ~□A and A and see whether they produce a contradiction when we have ƎA (A -> ◇~A) and ~◇~A -> ~A (I'm not formalizing properly here but whatever). You produce a reductio by assuming □A (you write this as "assuming B is not possible"), but we need not assume □A in order for the premises that translate to the classical free will thesis to be true.
I think that if you 1) stick with proper formalization and 2) consider why your reductio won't work for the initial free will thesis (not its contrapositive) you'll see why your proof is not valid. Again, in assuming our contrapositive to be true, we do not need to assume that the antecedent is true. And it is obvious why a free will thesis-ist is not going to say the antecedent is true: it would directly follow from □A that ~◇~A, which is exactly the negation of the free will thesis.
I'll try to formalize this properly, just for my own edification.
We'll only quantify over actions, to simplify a little. P = "is performed by a human" Free will thesis = Ǝx (Px ^ (Px -> ◇~Px) We'll assume f is such an action. It follows that: Pf ^ (Pf -> ◇~Pf) And therefore ◇~Pf Now it's also true that ~◇~Pf -> ~Pf and □Pf -> ~Pf For your reductio, we assume that this statement is true. There are three ways for it to be true. We'll run through all possibilities to see if any are consistent. 1. □Pf ^ ~Pf Clearly false. We already have Pf, so we cannot also have ~Pf.
2. ~□Pf ^ ~Pf Same as 1.
3. ~□Pf ^ Pf ~□Pf -> ◇~Pf ◇~Pf ◇~Pf ^ Pf I see no way to produce a contradiction from these truth values. Do you? Recall that our existing premises amount to: Ǝx (Px ^ (Px -> ◇~Px) Pf ^ (Pf -> ◇~Pf) ~◇~Pf -> ~Pf Each of these statements seems to come out true when we assume ~□Pf ^ Pf.
Cool story bro.
Just kidding hahaha. No I think I see what you're getting at now. My brain is starting to get tired at this point so I think I'll just surrender. You've probably knocked my proof down pretty convincingly. If I think of a proper response I'll get back to you on it.
On May 29 2014 10:04 MichaelDonovan wrote: Right, but the difference is that if empirical evidence suggests something that logic denies, then we conclude that our sense perception misled us. But if logic implies something that empirical evidence seems to deny, then we again conclude that our sense perception is wrong.
uhhmm.. no. There is no reason to believe that the world is logical. Logic is something we made up. Like English. It's a very specific kind of language with very precise rules. The reason logic helps us out a lot and would trick us into the idea that it is how the world works is because it is very abstract and shaped after very basic principles that occur in nature very often.
If we see something that does not work within our model we need to change our model, we can't change what we observe. At least no scientist does. That there is a external world independent from who observes it is the single most important premise that scientists need to believe, because if not, science doesn't make any sense.
So when it comes to free will, yeah logically it's a very strange concept because as many have pointed out before either stuff is determined, or it's random. But as I have to act as if I did have a free will, I think the question is kind of pointless anyway.
On May 29 2014 10:04 MichaelDonovan wrote: Right, but the difference is that if empirical evidence suggests something that logic denies, then we conclude that our sense perception misled us. But if logic implies something that empirical evidence seems to deny, then we again conclude that our sense perception is wrong.
uhhmm.. no. There is no reason to believe that the world is logical. Logic is something we made up. Like English. It's a very specific kind of language with very precise rules. The reason logic helps us out a lot and would trick us into the idea that it is how the world works is because it is very abstract and shaped after very basic principles that occur in nature very often.
If we see something that does not work within our model we need to change our model, we can't change what we observe. At least no scientist does. That there is a external world independent from who observes it is the single most important premise that scientists need to believe, because if not, science doesn't make any sense.
So when it comes to free will, yeah logically it's a very strange concept because as many have pointed out before either stuff is determined, or it's random. But as I have to act as if I did have a free will, I think the question is kind of pointless anyway.
Well yeah that's why I say that all of our logical conclusions are contingent on logic being reliable.
I only watched about 10 minutes of that Sam Harris video, but it seems to me that he's putting forth a non-falsifiable argument. No matter what course of action a person takes, he's going to say it's a result of neurobiology and randomness. If you follow the crowd, you're a result of your environment. If you are an outlier, there must be some detail that caused you to deviate. Did he expect to find a "free will gland" in the brain? One of my favorite expressions is "when all you have is a hammer, everything looks like a nail". Although in this case maybe it should be amended to "you only see nails". A materialistic determinist like Harris is not going to find evidence of free will any more than a Marxist is going to make a non historicist account. It is the lens through which he sees things. The New Positivists seem bound by their shocking contempt for other disciplines, but, really, that's the cardinal sin of modernity, isn't it?
This thread is a real monument (sepulcher?) to analytic philosophy. What should be a useful field of philosophy is instead an abomination. It boasts of its own primacy, ensuring that to the casual onlooker philosophy appears like an abstruse and meaningless endeavor while outwardly arguing for the banishment of the whole discipline before the tide of the hard sciences, flanked by sociology and psychology of course.
@Nina- I will continue to taunt you, per your instructions.
On the subject of breathing, I know that it is impossible to kill yourself by simply holding your breath. You will first lose consciousness, at which time your autonomic nerve system retakes control of your breathing. Thus, the instant you lose consciousness, you will have an inhalation reflex.
Cool stuff. I think we have free will, logical determinism be damned.
On May 29 2014 09:09 Lixler wrote: TL;DR of the following: for your reductio, you assume that the antecedent of the conditional is true. but the conditional can be true without the antecedent being true. if we assume, as we logically ought to, that our conditional as a whole is true, no contradiction follows. you have simply proven that the antecedent must be false (viz. that B could not be impossible)
let's fix your formalization somewhat: instead of using B, we'll just use ~A. we'll also introduce quantificational and modal symbols
so classical free will is: a -> ◇~a or more properly, since classical free will only says that some of our actions are freely willed: Ǝa (a -> ◇~a)
the contrapositive (for our assumed a) is now ~◇~a -> ~a or □a -> ~a
we can conclude a few things from this, but first let's run through your logical proof with our new symbols.
our assumption, in attempt of the reductio, is that ~a was not possible, or rather that □a.
from □a -> ~a we conclude both (this is trivially true) a ~a and obviously this is a contradiction.
well, what went wrong? this: in attempt to prove that your conditional led to a contradiction, you assumed that the antecedent was true. but we don't assume the truth of our antecedent in order to prove that our conditional was false. we assume that our conditional was true! and there are three ways for our conditional to be true. they are, as follows □a ^ ~a (which leads to a contradiction) ~□a ^ ~a ~□a ^ a
now our second set of truth values would lead to a contradiction, since we already assumed that a (we assumed there was some action such that we could have not done it). we are forced to conclude that ~□a ^ a. unfortunately for your proof, these two values do not lead to a contradiction.
Look, I really don't know this notation and didn't bother trying to figure it out, but I think it's just saying this:
On May 29 2014 06:17 spinesheath wrote: So you have a contradiction if you assume that there is some B that was not possible.
Lixler pointed out the major problem with your proof - namely, you're using first order logic, not modal logic. But if you do try to rewrite it in modal logic, I'd be wary about using contraposition. Ernest Sosa has a famous argument against contraposing subjunctive conditionals, which I think applies to your case as well.
On May 29 2014 08:39 Ghanburighan wrote: Interesting stuff, but here are a few issues:
a) You're using classical propositional logic to discuss possibilities, you'd need modal logic for a better representation. "Recall that we have assumed that B is not possible. Since B is not possible, we deduce: (4) ~B*." You can't do this formally without modal logic. And if you use modal logic, make sure you pick a system in which ~Diamond B* entails ~B*.
b) If you do adopt a modal logic, the original thesis would be better described as "at some point (world, time, etc.) where Diamond A holds, Diamond B holds as well."
c) I'm assuming you're utilizing material implication for "->" which has many known puzzles and problems. I don't think we can say much about free will or other concepts in a system in which B makes true A->B, i.e., where sitting in your office, makes true the statement: if you were blown up by a bomb this morning, then you're sitting in your office.
d) To attain (5) you make use of contraposition, but this rule doesn't correspond to our view of rational reasoning with probabilities. Consider Grice's Yog and Zog puzzle:
Yog and Zog are playing chess with special rules. Yog gets white 9/10 times and there are no draws. They have already played around 100 games, and Yog emerged victorious in 80 out of 90 of the games in which Yog had white, but Zog won all the remaining games. Now, the following two sentences have different probabilities.
a. If Yog had white, Yog won. b. If Yog lost, Yog had black.
The probability that the sentence (a) holds is 8/9 but it is only 1/2 for sentence (b). The problem with this situation is that (a) and (b) are equivalent if analyzed as material implication. This is because when you play chess, you use either the white or black pieces. So, playing with not white pieces is the same as playing with black pieces. And losing is the same as not winning when draws are taken out of the rules of chess. So if (a) is represented by p -> q then its contraposition ~q -> ~p is (b). But equivalent sentences should not have different probabilities, 8/9 and 1/2, respectively.
a) It is at this point in the proof where I am able to get rid of the need for any modal operators. I only need ~<>B* to show ~B*. And yes, I should have included that somewhere in my proof, but I am assuming that B being impossible entails that B* cannot be true.
b) Sure, I don't see any problem with saying it like that. Modal logic gets kind of messy though sometimes, so I wanted to try to do away with it.
c) This objection would be problematic if it were not for the fact that all of my statements in this arguments are based only on the logical structure of the proposition. That is, we don't really care if it makes sense empirically. What we're showing is that the classical free will thesis is logically incoherent. This doesn't say much about free will. It just says that the way the classical thesis is written leads to contradictions.
So, the fact that being blown up this morning makes it impossible for me to be sitting in my office isn't really important. If it were, we would include that statement in our argument, and the contradiction would be clear. I'm not sure if this a sufficient response to your objection though, so hammer it a bit more if you're dissatisfied.
d) That's a fun example. I'll have to think about that for a bit. But I don't think it's a problem for my argument because we either have free will or we don't. We either do action A or we do action not A. It's not like If you do action B, then you probably didn't do A. Or something like that. When you have mutually exclusive sets, the probability of their intersection is zero since their intersection is the empty set. I dunno if that addresses the problem completely, so again, hammer it some more if you're not satisfied.
Let's address (b) as that's the most important one. Diamond A wedge Diamond B isn't a contradiction, you won't be able to derive Diamond B and ~Diamond B from it unless you introduce a formula which is a contradiction itself. But then the problem is with that assumption and not free will.
Basically, as others have said, your formalism fails because you're allowing moves which modal logic would not allow.
***
Regarding (c), I can say that free will is linked to causation. We can either influence the chain of events or we cannot. If you represent causation with material implication, you can derive things which we know do not correspond to causation itself. This is basically the same as (d), as the logical formalism makes counter-intuitive predictions about causation, we should identify the problem with the logic, and not with free will. And besides not using modal logic, the biggest problem is the use of material implication instead of more refined accounts of implication such as strict implication, relevant implication, or Kratzer's context-sensitive conditionals.
This was a really cool blog, I like practising my logic skills so it was fun to follow along the discussion. To be honest I didn't follow Lixler's analysis that well either because I'm not used to the symbols and am not clear on what they mean, but I think I also noticed an error in your proof and would like to point it out in more readily comprehensible terms.
I think the biconditional statement needs to be modified, because as it stands it assumes that A* and B* are both possible. But the contrapositive of your proposition indicates that if B* is impossible, then A* is impossible. So there should be the possibility that A* and B* are both impossible.
So to be clear, B is any distinct action that is not A. The biconditional should be modified to this:
If B and A both exist as possible actions such that B* and A* are both possible, then:
(3) B* <-> ~A*
This way it makes sense, because B needs to be possible before an agent performs the action (B*), and the contrapositive requires that A be possible before A* is.
So then when you start with the assumption that B is impossible, you do indeed get ~B* as a consequence, but before you continue on to using the biconditional I think you would need to establish that A is actually possible (and consequently A*), which you can't really get from anything else unfortunately. Thus it would be invalid to use the biconditional in your fifth step, and the argument just ends there uncompleted.
So that's the main thing: The biconditional assumes both actions are always possible, while the contrapositive to your proposition considers the possibility that both may be impossible. The biconditional thus needs to be modified to allow for these possibilities
edits: Grammar. By the way I hope you enjoyed your counterstrike session!! I used to love that game
On May 29 2014 09:09 Lixler wrote: TL;DR of the following: for your reductio, you assume that the antecedent of the conditional is true. but the conditional can be true without the antecedent being true. if we assume, as we logically ought to, that our conditional as a whole is true, no contradiction follows. you have simply proven that the antecedent must be false (viz. that B could not be impossible)
let's fix your formalization somewhat: instead of using B, we'll just use ~A. we'll also introduce quantificational and modal symbols
so classical free will is: a -> ◇~a or more properly, since classical free will only says that some of our actions are freely willed: Ǝa (a -> ◇~a)
the contrapositive (for our assumed a) is now ~◇~a -> ~a or □a -> ~a
we can conclude a few things from this, but first let's run through your logical proof with our new symbols.
our assumption, in attempt of the reductio, is that ~a was not possible, or rather that □a.
from □a -> ~a we conclude both (this is trivially true) a ~a and obviously this is a contradiction.
well, what went wrong? this: in attempt to prove that your conditional led to a contradiction, you assumed that the antecedent was true. but we don't assume the truth of our antecedent in order to prove that our conditional was false. we assume that our conditional was true! and there are three ways for our conditional to be true. they are, as follows □a ^ ~a (which leads to a contradiction) ~□a ^ ~a ~□a ^ a
now our second set of truth values would lead to a contradiction, since we already assumed that a (we assumed there was some action such that we could have not done it). we are forced to conclude that ~□a ^ a. unfortunately for your proof, these two values do not lead to a contradiction.
Look, I really don't know this notation and didn't bother trying to figure it out, but I think it's just saying this:
On May 29 2014 06:17 spinesheath wrote: So you have a contradiction if you assume that there is some B that was not possible.
Then obviously everything is possible.
On May 29 2014 20:47 zf wrote: Lixler pointed out the major problem with your proof - namely, you're using first order logic, not modal logic. But if you do try to rewrite it in modal logic, I'd be wary about using contraposition. Ernest Sosa has a famous argument against contraposing subjunctive conditionals, which I think applies to your case as well.
I don't think I'm saying either of these things. Zf's point is fairly obvious - we ought only deal with possibility using modal logic - but the exact problem I'm pointing out in OP's proof is not rooted specifically in his choice of logic. Specifically, he sets up his reductio falsely. Quoting it now for ease of reading:
Contrapositive of the proposition: If it was not possible for the agent to have done B, then the agent did not do A.
We will attempt to disprove the proposition by showing that its logically equivalent contrapositive leads to a contradiction.
So we assume (for reductio) that it was not possible for the agent to have done B. If the proposition is true, then it should follow that the agent did not do A. We will show that this is not the case.
When we attempt a reductio of some proposition, we assume that proposition is true and work to derive a contradiction. OP thinks he is doing this when he assumes "that it was not possible for the agent to have done B," but in fact he needs to assume "If it was not possible for the agent to have done B, then the agent did not do A." There are three possible ways for this latter conditional to be true. The first, which OP demonstrates is contradictory, is for it to have been possible for the agent to have done B and for the agent to not have done A. The second, which also will not work (as I demonstrated in the symbolization) is for it to have been possible for the agent to have done B and for the agent not to have done A. The third, which leads to no contradiction, is for it to have been possible for the agent to have done B and for the agent to have done A. When these two statements hold (i.e. when the antecedent of the conditional is false while its consequent is true), the conditional is true (as we assumed), yet no contradiction follows. So OP has failed to demonstrate that the classical free will thesis is contradictory.
The specific move where OP goes wrong involves a fairly common mistake made by people learning formal logic. Namely, he assumes that the only way for a conditional to be true is for both the antecedent and the consequent to be true. But this is not so. As it turns out, we can derive a contradiction from any conditional and its contrapositive if we don't assume this (specifically because the equivalence of a conditional with its contrapositive relies on the fact that the conditional is true when both its parts are false, but whatever). Let's take the following example.
If I love my wife, I will buy her a gift for our anniversary. Contrapositive: If I will not buy my wife a gift for our anniversary, I do not love her. Now let us assume 1) that a conditional can only be true when both its parts are true and 2) that our contrapositive is true. This means that we have to assume that it is true 1) that I will not buy my wife a gift for our anniversary and 2) that I do not love her. But if both these are the case, and it is further the case that a conditional can only be true when both parts are true, then it follows that our initial conditional is false. But this leads us to a contradiction, since the contrapositive (which we assumed to be true) is supposed to be logically equivalent to the initial conditional, i.e. true when it is true, false when it is false.
We cannot simultaneously maintain that a conditional is only true when both its parts are true and that a conditional is logically equivalent to its contrapositive. Since OP does this in his proof, it is invalid. Indeed, we could prove anything we wanted if we tried to maintain both these things. Hopefully it is clear now where and why OP's argument goes wrong, although obviously there are problems with his symbolization that don't have anything to do with my qualm.
On May 29 2014 07:14 MichaelDonovan wrote: [quote]
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
That's because philosophers love to argue. Until the real scientist comes along and puts the matter to rest with empiric evidence instead of pure thought .
Facetiousness aside, you should really watch the video. Sam makes a compelling argument on why the very concept of free will doesn't really make sense.
Empirical evidence is hard to rely on when our sense perception is so limited
There are really two versions of the world: The world as we perceive it to be and the world as it actually is outside of our experience of it. Truth can be found in the world as it actually is. What we perceive is only contingent on the accuracy and completeness of our sense perception. The only way to get at the way the world actually is, it would seem, through rational thought and deductive reasoning. A fairly lofty task though, to be sure.
Empirical evidence is hard to rely on? Is that why science doesn't make any progress?
The best method that we have to find out truth about the world, an objective truth, is scientific method. Rational thought and deductive reasoning go out the window once we're confronted with something that doesn't seem rational, eg. quantum mechanics.
Well the problem is that empirical evidence isn't foolproof. We can only gather evidence from what we can sense. How do we know we're not in the matrix world, for example? We don't really know that do we? No amount of empirical evidence can prove that we aren't dreaming or that we aren't just brains in vats being stimulated with the illusion of experience. This is because any empirical evidence we gather is contingent upon our trust for our ability to sense it.
Quantum mechanics is not irrational necessarily. It just defies some our previous assumptions about the world. It renders many statements false that were once though to be true. That doesn't mean it's logically incoherent. It just means we don't understand it based on our current assumptions.
We can't disprove that we're not living in the matrix world. We can't disprove an infinite number of things. That's why we don't pay attention to things unless there's some evidence for them (well, except religion). It wouldn't be very reasonable to start thinking about things that we have no shred of evidence for (like if there's a teapot orbiting around Jupiter). Sure, you can lock yourself up in a room and try to use deductive reasoning all you want, but until you actually go outside of the room and look at what the world is telling you, you won't make any progress and in fact, most of your deductions will be simply wrong.
On May 29 2014 08:38 MichaelDonovan wrote:
On May 29 2014 08:36 ninazerg wrote:
On May 29 2014 07:14 MichaelDonovan wrote:
On May 29 2014 07:09 2Pacalypse- wrote: A good video on free will by Sam Harris that made it painfully obvious (to me) that free will is an illusion:
I would be wary of believing anything that seems to be "painfully obvious." If something like this were painfully obvious, we wouldn't be arguing about it for hundreds of years.
So the length of time by which we argue something determines how obvious it may or may not be?
Determines is a wrong word. Indicates is might be better. What I'm saying is that if the guy in this video actually came up with a solution so obvious that you couldn't argue with it, then I would have heard about it by now, and there would be nothing more to argue. But since people are still arguing, his solution can't be all that obvious.
I did write it became obvious to *me*. This was not a formal scientific theory that Sam proposed, but rather a compelling argument that "makes sense" once you think about it. There are people who challenges his argument though, like philosopher Dan Dennett, but from what I've read it doesn't look like a very good challenge.
Also, people are still arguing about creation vs evolution so you can't possibly take the length of the arguing as an indicator to one's side validity. Perhaps just watch the video or read about Sam's arguments on free will.
I'm not saying that empirical endeavors are pointless. I'm just saying that you can't really value empirical evidence too highly and trust it too much.
And the only way of getting past the limits of our sense perception is probably to use logical deductions. You can't just go by empirical evidence for answers to your questions because your evidence is so very limited. That's not to say that logic alone can answer all your questions. Logic is merely a formal way of thinking. You have to fill the propositions with empirical assumptions on your own. And then any truth you derive is contingent upon those assumptions, which are contingent upon your sense perception.
And that's what scientific method is: rational thinking applied to empiric evidence.
Right, but the difference is that if empirical evidence suggests something that logic denies, then we conclude that our sense perception misled us. But if logic implies something that empirical evidence seems to deny, then what do we again conclude that our sense perception is wrong.
What I'm saying is that sense perception and empirical evidence are always the first suspects for error. Logic is more trustworthy.
Uhm, no, it's the other way around.
When we demonstrated with empirical evidence that the electron can be at the two places at once, something that seems logically impossible, we didn't dismiss it due to our sense perception misleading us.
Sure, you can try to "update" logic to fit with the reality, but you can't update reality to fit with your logic.
While I think that what he said is incorrect about dismissing empirical evidence over logic, quantum mechanics is not really illogical. It has its own rules which it follows, which just seems counter intuitive to everyday human experiences.
Logic is simply a way of connecting one statement to another. It's not that logic dictates that it's impossible for the electron to be at two places at once, it's the assumption of how a particle should act that is wrong. Initial assumptions from which the logic is derived can be wrong, but logic itself is not wrong.
But at the same time, logic is just a play on words and doesn't really apply to reality unless you actually have something like empirical evidence to start from which you know is correct in the real world.
What I'm talking about is really all kinds of logic such as mathematical logic, logical probabilism, and whatever other kinds of valid logic you can think off. If he's only talking about classical logic, then sure feel free to bash him
On May 29 2014 08:20 micronesia wrote: It's unfortunate that I don't remember the mathematical rules of logic that well, but I don't see how you can use logic alone to prove the following:
It is not possible for every action to have at least one alternative, mutually exclusive action.
I don't think there are enough tools to work with. Putting technical lines of math aside, what is the reason why the above statement is true?
What you're getting at is the only non-formal assumption that I feel can be poked at in my proof.
My reasoning is as follows:
Recall that we are assuming for reductio that the classical free will thesis is true (we are then showing that a contradiction arises from this).
So since we are assuming classical free will exists, it would seem like no matter how pidgeon-holed into a line of action a person may seem to be, he always has the option of not doing that action, which is a contrary action in itself.
Here's why I say this:
Completing an action requires a break in inertia of sorts. That is, in order to execute an action, one must go from a state of inaction to a state of action and this requires some kind of effort, or at least a willing. If one does not will that the action be executed, they can choose not to act.
The way I think of it is like this: Imagine you are walking on a narrow path over an abyss. You cannot jump off the sides of the path because there is an invisible wall or something. And as you walk, the path behind you gets deleted such that you cannot go the other way. So it would seem as though you have only one choice, which is to continue walking forward. But it turns out that you still have the option of standing still.
I dunno. Maybe this is a weird example. But I think as long as we are assuming free will to exist (for reductio) we can assume that an action that you will should also have an alternative option if you were not to will it. It's easy to imagine a case were you are tide up with a sock in your mouth and you can't move, and say well, there seems to be no other option... But you have the option of willingly accepting your immobility or at least trying to escape (pointless as it may be). The action of accepting your captivity and the action of fighting it (regardless of the effectiveness of your struggle, which may be zero) are contrary actions.
Everything above seems to be an explanation supporting this classical free will thesis... following along using this plain-English approach, what is the contradiction?
The contradiction is probably something like this:
Taking a step forward is a sufficient condition for not having stood still. Not having stood still is a necessary condition for having stepped forward. Having stood still is a sufficient condition for not having stepped forward. Not having stepped forward is a necessary condition for having stood still.
So if I chose to step forward, this makes it the case that I did not choose to stand still. But not having chosen to stand still is the only way that it could have been possible to step forward. Thus, if you stepped forward, it must be the case that standing still was not possible.
Something like that.
Hm, when you put the 'contradiction' in plain English like this, it seems like your argument is teleological. As others have said, you are using your conclusion as evidence of your conclusion in a somewhat circular manner. Once again, I will not point to logical inaccuracies in your 'proof' as I do not have the necessarily knowledge to do so, but it seems a bit ridiculous to me to say:
"In order to choose an action, I had to not choose other actions, but it was necessary for me to not choose those other actions in order to choose the first action, so really I didn't have a choice," which is, in essence, what your contradiction is. It's almost a semantic argument rather than a logical one, when looked at in words rather than proofs.
Well... I'm not really satisfied with the way I worded it in plain English. It's kind of hard to say it properly because it's not all intuitive. Trying to explain why 1 + 1 = 2 in English without using formal logic to derive this truth from definitions leads to an explanation that won't really be satisfying and is probably full of holes. And I'm not sure I put the logic into words correctly there either...
Not having stepped forward is a necessary condition for having stood still. Was it possible for you to have stood still given that you stepped forward? No, because not having stepped forward is a necessary condition for having stood still. So given that you have stepped forward, it is impossible that you could have stood still.
I dunno.
All that tells me is that I can't change an action I made in the past, but has very little implications for what I'm going to do in the future, unless you mean to say that you're going to do what you do because you can't not do what you're going to do. But if that's the case, all that means is that I'm going to make decisions, and it is impossible for me to not make decisions, because if I make a decision not to decide, I'm still making a decision and cancelling out my decision to not decide anything.
EPT
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