Is omniscience compatible with human freedom?

[Zetherin]

Originally Posted by fast

To add further:

He knew what I going to do before I knew what I was going to do. One thing I did was something I had to do, and another thing I did was something that I didn’t have to do but did anyway.

In the first case, He knew I was going to do it before I knew I was going to do it, and He knew that I had to do it.

In the second case, He knew I was going to do it before I knew I was going to do it, and He knew that I was going to make the choice and do it anyway.

And I hope you don't think I'm disagreeing with this. Because, I noted several times that God knows all our actions, whether we are compelled to do them or not.

[kennethamy]

Originally Posted by Zetherin

I think I've found the root of the miscommunication between ACB and I, and you and fast:

When we say "could have done otherwise", we are meaning could have otherwise from what God knows. When you guys say "could have done otherwise", you are meaning could have done otherwise from other possibilities that you could have done, not that it is otherwise from what God knows.

I think we all agree that we don't do things because God knows, but we can only do things that God knows.

Well, yes. But that is not peculiar to God. You can do also only things that I know you will do. It is just that God knows everything you will do, and I do not. But you cannot, if I know you will do A, do other than A. If you did, I would not know that you would do A in the first place. That is how the word, "know" works. Nothing special about how it works when God knows. It is (1) impossible if A knows you will do p, for you to do other than p. But not, (2) if A knows you will do p, it is impossible that you do other than p. To infer the (2) from (1) is to commit the modal fallacy. And that is an important source of the belief that omniscience is incompatible with free will.

[ACB]

Originally Posted by kennethamy

Yes. Had I done differently (which I did not) then He would have known that. But since I did what I did, He knew that was what I was going to do. God knew what I would do because that was what I was going to do. But, I did not do what I did because God knew it.

Either the future is predetermined (in which case I have no free will) or it is not (in which case the underlined phrase above makes no sense to me). If I am free to choose, how can there possibly exist a fact about my choice before I choose? How can facts about the future exist already if the future is still open?

To answer "Because God is omniscient about the future" would beg the question. It may be the case that future facts do not already exist, in which case God cannot be omniscient about the future. Do you see my point?

[Zetherin]

Originally Posted by kennethamy

Well, yes. But that is not peculiar to God. You can do also only things that I know you will do. It is just that God knows everything you will do, and I do not. But you cannot, if I know you will do A, do other than A. If you did, I would not know that you would do A in the first place. That is how the word, "know" works. Nothing special about how it works when God knows. It is (1) impossible if A knows you will do p, for you to do other than p. But not, (2) if A knows you will do p, it is impossible that you do other than p. To infer the (2) from (1) is to commit the modal fallacy. And that is an important source of the belief that omniscience is incompatible with free will.

I don't understand the modal fallacy, even though I've researched it before in the past.

"The following argument appears to be valid and to have true premises; yet its conclusion is false.

If Paul has one daughter and two sons, then Paul has to have at least one son.
Paul has one daughter and two sons.
Therefore, Paul has to have at least one son.

The problem is that although Paul (my brother) does have a son (he in fact has two sons), he does not have to have any. His having any children at all, as well as the exact number, are contingent matters, not matters of logical necessity." (this is from a website I've researched)

I don't understand what logical necessity means, I think. I do not see how if Paul has two sons, that he doesn't have to have at least one son. Wouldn't his having two sons entail that he has at least one son? Why not?

Please help.

---------- Post added 12-02-2009 at 02:00 PM ----------

By the way, I just wanted to toss this into the conversation: Argument from free will - Wikipedia, the free encyclopedia

I'm surprised it hasn't been brought up before. (Or maybe it has?)

[ACB]

Originally Posted by Zetherin

I don't understand what logical necessity means, I think. I do not see how if Paul has two sons, that he doesn't have to have at least one son. Wouldn't his having two sons entail that he has at least one son? Why not?

I think part of the problem is due to carelessness with tenses. I would argue that if Paul has two sons, it is true that he didn't have to have at least one son, but false that he doesn't have to have at least one son.

[Zetherin]

Originally Posted by ACB

I think part of the problem is due to carelessness with tenses. I would argue that if Paul has two sons, it is true that he didn't have to have at least one son, but false that he doesn't have to have at least one son.

Oh, I see. Didn't because he didn't have to knock up his wife in the first place. But because he did in fact knock up his wife, he does have to have at least one son now (because he now has two sons). Is that what you're getting at?

That's not what they're getting at, though, I don't think. The professor here is making a point regarding 1.) Logical necessity and 2.) Contingent truths. Neither of which I really understand.

[kennethamy]

Originally Posted by ACB

Either the future is predetermined (in which case I have no free will) or it is not (in which case the underlined phrase above makes no sense to me). If I am free to choose, how can there possibly exist a fact about my choice before I choose? How can facts about the future exist already if the future is still open?

To answer "Because God is omniscient about the future" would beg the question. It may be the case that future facts do not already exist, in which case God cannot be omniscient about the future. Do you see my point?

Why cannot it be a fact that the Sun will rise tomorrow (if it rises)? Of course future futures do not exist. But (as Russell points out) past futures do exist. God was (and is) omniscient about them, and is omniscient about future futures too. The future is still open, but that does not mean that what happens in the future does not happen. And God is omniscient about what happens in the future. Indeed, it may be that for Him, it is no different from being omniscient about the past.

---------- Post added 12-02-2009 at 02:28 PM ----------

Originally Posted by ACB

I think part of the problem is due to carelessness with tenses. I would argue that if Paul has two sons, it is true that he didn't have to have at least one son, but false that he doesn't have to have at least one son.

Obviously. It is a logical truth that if A has two sons he has one son. But it is not a logical truth that he has one son.

---------- Post added 12-02-2009 at 02:37 PM ----------

Originally Posted by Zetherin

Oh, I see. Didn't because he didn't have to knock up his wife in the first place. But because he did in fact knock up his wife, he does have to have at least one son now (because he now has two sons). Is that what you're getting at?

That's not what they're getting at, though, I don't think. The professor here is making a point regarding 1.) Logical necessity and 2.) Contingent truths. Neither of which I really understand.

It is logically necessary that if A knows that p, then p is true. But it is not logically necessary that if A knows that p, that it is logically necessary that p is true. In other words, we can know other than logically necessary truths. Even if it is logically necessary that if we know something, that something is true.

That isn't (it seems to me) hard to understand.

[ACB]

Originally Posted by kennethamy

Why cannot it be a fact that the Sun will rise tomorrow (if it rises)? Of course future futures do not exist. But (as Russell points out) past futures do exist. God was (and is) omniscient about them, and is omniscient about future futures too. The future is still open, but that does not mean that what happens in the future does not happen. And God is omniscient about what happens in the future. Indeed, it may be that for Him, it is no different from being omniscient about the past.

If future futures do not exist, then logically God cannot be omniscient about them. If they form part of the totality of possible knowledge, they must exist. Even God cannot do what is logically impossible.

EDIT:

If p is true, is it logically necessary that p is true? I see an ambiguity here.

[kennethamy]

Originally Posted by ACB

If future futures do not exist, then logically God cannot be omniscient about them. If they form part of the totality of possible knowledge, they must exist. Even God cannot do what is logically impossible.

I agree with the first. But I don't understand the notion of "forming part of the totality of possible knowledge" bit. Why, if it is possible to know them, must they exist? If it is possible to know them, then isn't it possible not to know them? I think I don't understand the idea of possible knowledge.

[ACB]

Originally Posted by kennethamy

If it is possible to know them, then isn't it possible not to know them?

No, not for an omniscient being. If it is possible to know them, then God does know them. But if they don't exist, it's not possible to know them, so he can't.