21 Aug 10
Originally posted by KellyJayO.K., but you don't need the libertarian account of free will if all you want is choice without coercion.
I believe if it can be known God will know it; however, if it is up to you than
whatever you choose will be the answer. I can know an apple tree will produce
apples not sure how many when but I can know that baring something out of
my knowledge coming in and changing things. So there are things that within the
scope of time that can happen God will know ...[text shortened]... ge, but
God's ability to make sure it is free and not some designed outcome by God.
Kelly
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21 Aug 10
Originally posted by bbarrYes, if A is I had coffee and toast but in that world I had waffles.
O.K.
(4) Necessarily, God knows that you will A.
So, the negation of (4) would be:
~ Necessarily, God knows that you will A.
Which is equivalent to:
Possibly, ~ God knows that you will A.
Which, in possible worlds semantics reads:
There is at least one world where God does not know that you will A.
So you think a theist would be happy with this?
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21 Aug 10
What occurred to me was that the scope of the necessity operator might not reach into the propositional content.
So at w god knows I had coffee and toast whereas at w' god knows I had waffles.
Given that, what is necessary is that god knows what I ate, but it would be incorrect to say that necessarily god knows I had coffee and toast, since there is at least one world, w', where this is not the case.
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21 Aug 10
Originally posted by bbarrActually, I don't think that the negation of "God knows I will A" entails "God's knowledge is deficient". It might simply be that God knows not-A.
If you say so, but I have a proof that says otherwise. You can find it by following the link in the original post.
21 Aug 10
Originally posted by bbarrThe libertarian theist should be okay with that since he already thinks there are possible worlds where it is not the case that he will A.
O.K.
(4) Necessarily, God knows that you will A.
So, the negation of (4) would be:
~ Necessarily, God knows that you will A.
Which is equivalent to:
Possibly, ~ God knows that you will A.
Which, in possible worlds semantics reads:
There is at least one world where God does not know that you will A.
So you think a theist would be happy with this?
If I understand the gist of Lord Shark's and Conrau K's counter, it is in the denial that 4) is justified on the basis of the theist's commitment to infallibility of G. For example, if the theist is committed to G's being infallible, it should only commit him to something like the following:
Necessarily, if you will A, then G knows that you will A.
But they deny that the theist would be committed to 4).
I still confess to being a bit confused, but that is my current take on it.
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21 Aug 10
Bbar, I think that the problem in your argument is actually premise 7. When you say possibly Q, that possibility entails only that it is true that you will not-A in some other world and if we limit the accessibility relation then there is no contradiction with 8. If we use world-semantics, we avoid the whole reductio ad absurdum.
21 Aug 10
Originally posted by Lord SharkBut what is the other world? If it's a possible world, then God only knows contingently. If it is some alternate dimension; some actual world with it's own God, then what reason is there for thinking that an identity relation obtains between me in W1 and "me" in W2?
What occurred to me was that the scope of the necessity operator might not reach into the propositional content.
So at w god knows I had coffee and toast whereas at w' god knows I had waffles.
Given that, what is necessary is that god knows what I ate, but it would be incorrect to say that necessarily god knows I had coffee and toast, since there is at least one world, w', where this is not the case.
And what does it mean to say that the actual content of a proposition might not be in the scope of it's necessity operator? The necessity operator operates on P, whether P is 'God knows that you will eat eggs for breakfast', or 'God knows that you will have coffee and toast for breakfast', or... What else could it operate on?
21 Aug 10
Originally posted by Conrau KNo, that's not how possibility works, and if there is a problem it is certainly not with (7). (7) just follows from the libertarian account of free will. If libertarianism is correct, then it is possible, in the actual world, that I could have done otherwise than I in fact do. One way of saying this is that there are other possible worlds, otherwise identical to this world (or very nearby), where I did in fact do otherwise. You can't have it both ways, such that something is necessary in one world and merely contingent in another; that's simply contradictory. Necessity cuts across possible worlds.
Bbar, I think that the problem in your argument is actually premise 7. When you say possibly Q, that possibility entails only that it is true that you will not-A in some other world and if we limit the accessibility relation then there is no contradiction with 8. If we use world-semantics, we avoid the whole reductio ad absurdum.
21 Aug 10
1 edit
Originally posted by LemonJelloO.K., the claim under consideration is:
The libertarian theist should be okay with that since he already thinks there are possible worlds where it is not the case that he will A.
If I understand the gist of Lord Shark's and Conrau K's counter, it is in the denial that 4) is justified on the basis of the theist's commitment to infallibility of G. For example, if the theist is committed to G' ...[text shortened]... mitted to 4).
I still confess to being a bit confused, but that is my current take on it.
Necessarily, if P, then God knows P.
Suppose P.
Now, is it necessary that God knows P?
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21 Aug 10
2 edits
Originally posted by bbarrNo, that's not how possibility works, and if there is a problem it is certainly not with (7).
No, that's not how possibility works, and if there is a problem it is certainly not with (7). (7) just follows from the libertarian account of free will. If libertarianism is correct, then it is possible, in the actual world, that I could have done otherwise than I in fact do. One way of saying this is that there are other possible worlds, otherwise identic y contingent in another; that's simply contradictory. Necessity cuts across possible worlds.
That's right. I am not saying that 7 is wrong; I am saying that it is not properly defined. You are saying possibly Q and interpreting it to mean that "you will not-A in the same world" when in fact possibility only requires that there be some world (whether the same or another) in which Q obtains.
You can't have it both ways, such that something is necessary in one world and merely contingent in another; that's simply contradictory. Necessity cuts across possible worlds.
Perhaps how you define necessity. However, I have explicitly stated that I am rejecting S5 necessity so it is not immediately granted that there is an accessibility relation across worlds. I believe that distinction is quite vital. It one thing to say God necessarily knows I will A in one world; quite another to say it is necessary across all worlds.
This is how I would account for libertarian free will:
1. Possibly I will do A.
Hence, 2. w1, I will do A.
3. Possibly, I will do not-A.
Hence, 4. w2, I will do not-A.
However, P: God is infallible.
Hence, 5. in w1, God necessarily knows I will do A.
Hence, 6. in w2, God necessarily knows I will not-A.
Now for some reason you want an accessibility relation between w1 and w2. I don't understand why you need such a strong definition of necessity, nor do I see how a theist would want to endorse it. It seems to me that a theist would only say that God's knowledge of A is only necessary in worlds where I choose A. So it seems really strange that by your notion of necessity here, that suddenly it must be true that God's knowledge then requires me to A in every world.
21 Aug 10
1 edit
Originally posted by bbarrThat is also the question I have. I think the answer is no. If the supposition were that it is necessary that P, then I think there would be a natural transfer of necessity to God's knowing that P, given also the claim under consideration. But then it seems that supposition would just be question-begging.
O.K., the claim under consideration is:
Necessarily, if P, then God knows P.
Suppose P.
Now, is it necessary that God knows P?
21 Aug 10
1 edit
Originally posted by Conrau K(7) is properly formulated, you just don't like the formulation. But the formulation simply follows from what the libertarian actually wants. The libertarian wants it to be true of the actual world that it was a live metaphysical option that one could have done otherwise than one in fact did.
[b]No, that's not how possibility works, and if there is a problem it is certainly not with (7).
That's right. I am not saying that 7 is wrong; I am saying that it is not properly defined. You are saying possibly Q and interpreting it to mean that "you will not-A in the same world" when in fact possibility only requires that there be some world (whe hat suddenly it must be true that God's knowledge then requires me to A in every world.[/b]
Now, I'm not sure why your rejection of S5 is relevant to my argument, since nothing in my argument relies on anything other than the Distribution Rule and the translation rules for modal operators.
If you reject S5 necessity, then, by definition, you reject at least one of the following:
(K) If necessarily (If P, then Q), then (If necessarily P, then necessarily Q).
(T) If necessarily P, then P
(5) If possibly P, then necessarily possibly P.
So, which do you reject? And how does your rejection of K, T, or 5 vitiate my argument?
21 Aug 10
Originally posted by LemonJelloSo, if the answer is 'no', then:
That is also the question I have. I think the answer is no. If the supposition were that it is necessary that P, then I think there would be a natural transfer of necessity to God's knowing that P, given also the claim under consideration. But then it seems that supposition would just be question-begging.
~ Necessarily God knows P.
Which yields:
Possibly ~ God knows P.
So here we are left both with the supposition that P and the possibility that it is not the case that God knows P. I don't think the theist would be happy with this.
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21 Aug 10
1 edit
Originally posted by bbarrThe libertarian wants it to be true of the actual world that it was a live metaphysical option that one could have done otherwise than one in fact did.
(7) is properly formulated, you just don't like the formulation. But the formulation simply follows from what the libertarian actually wants. The libertarian wants it to be true of the actual world that it was a live metaphysical option that one could have done otherwise than one in fact did.
Now, I'm not sure why your rejection of S5 is relevant to my ...[text shortened]... .
So, which do you reject? And how does your rejection of K, T, or 5 vitiate my argument?
Exactly. To say that it is a 'metaphysically live option' simply entails that there is a world in which it happens. I don't see why you feel the need to make a distinction between 'real' worlds and hypothetical ones here. The point is that from 7 you suggest that the possibility of Q entails that you will do A in the same world but it doesn't.
So, which do you reject? And how does your rejection of K, T, or 5 vitiate my argument?
Because if you reject S5, then it is possible to say for one world that something is necessary but for another world it is not. So simply because it is in w1 that God necessarily knows I will do A does not entail that in w2 that I will do A.