I think we are on the same page, GdB, but I was confused by a conflict you seemed to see between two claims:
First claim (Repeated twice):
GdB - 22 August 2012 10:40 PM
I am saying the sentence “If this water is heated enough, it will boil” is meaningful and true, even if it was determined by the history of the universe that I would not heat the water.
GdB - 22 August 2012 10:40 PM
I am saying that the sentence “If I had wanted to I could have gone to Paris last weekend” is meaningful and true, even if the universe is so fixed and determined as it is.
Second claim:
GdB - 22 August 2012 10:40 PM
BTW It now even seems that Doug takes a more radical standpoint than I do, seen from your view:
dougsmith - 22 August 2012 08:28 AM
So I understand what you’ve just written as, “He says even if the universe is deterministic, he could have gone to Paris last weekend.” (This is the only meaningful and true part of the sentence that remains once we cut out the necessary falsehoods). And I agree with the quoted sentence. Even if the universe is deterministic, he could have gone to Paris last weekend.
For me that is a minor point: I suppose Doug means “there is no physical law forbidding for me to have gone to Paris last weekend”. And that is true of course:
- Paris is close enough that I can do it travelling below lightspeed
- Paris is close enough that in the time frame of a weekend I can get there by train, and back again
- There is no contradiction between the laws of physics and my brain being in the state ‘wanting to go to Paris’
- etc…
In this sense it is perfectly possible that I could have gone to Paris, even if the universe banged in such a way that the ‘laws of physics decided’ that I did not go to Paris.
What confuses me is that it seems plain to me we are saying precisely the same thing. Where is the “more radical standpoint”? By “the universe is deterministic” I mean precisely the same as you do when you say “the universe is determined”. So I don’t even see the “minor point” that you mention afterwards. (Of course, I agree with your points about Paris).
For me that is a minor point: I suppose Doug means “there is no physical law forbidding for me to have gone to Paris last weekend”. And that is true of course:
Of course it isn’t true, this is the main point of disagreement. If you went to Paris last weekend all else (exactly) the same, indeterminism would be true. The laws of nature would be different.
That’s physically impossible by definition. This is flat out wrong and what the main fuss is about.
What confuses me is that it seems plain to me we are saying precisely the same thing. Where is the “more radical standpoint”? By “the universe is deterministic” I mean precisely the same as you do when you say “the universe is determined”. So I don’t even see the “minor point” that you mention afterwards. (Of course, I agree with your points about Paris).
Perhaps I’m missing something?
Or I am…
I am intended to agree with Stephen on the following point: given the universe as it was, causing me not to want to go to Paris, it is impossible that I wanted to go to Paris. (And if Stephen is stressing me like that: physically impossible.) Compare: If I heat the water long enough, it is impossible that it will not boil.
But, and that is the point Stephen does not accept: the sentence “If I wanted to, I could have gone to Paris last weekend” is still a meaningful and (in my personal case) a true sentence. He defends this position by saying it was (physically?) impossible for me to want to go to Paris in this actual universe.
Stephen, have I correctly described your position?
For me that is a minor point: I suppose Doug means “there is no physical law forbidding for me to have gone to Paris last weekend”. And that is true of course:
Of course it isn’t true, this is the main point of disagreement. If you went to Paris last weekend all else (exactly) the same, indeterminism would be true. The laws of nature would be different.
That’s physically impossible by definition. This is flat out wrong and what the main fuss is about.
The physical law has nothing to do with the initial conditions. A law is a regularity that holds for all times and places. Initial conditions are the way things were for an instant in time.
This doesn’t mean that all else exactly the same you would have been able to go to Paris last weekend. Only that your not having gone to Paris last weekend hasn’t got anything essentially to do with the physical laws; it has to do with the initial conditions. (Assuming determinism).
Of course it isn’t true, this is the main point of disagreement. If you went to Paris last weekend all else (exactly) the same, indeterminism would be true. The laws of nature would be different.
That’s physically impossible by definition. This is flat out wrong and what the main fuss is about.
Which laws of physics are then not adhered to, if I would have wanted to go to Paris?
This doesn’t mean that all else exactly the same you would have been able to go to Paris last weekend. Only that your not having gone to Paris last weekend hasn’t got anything essentially to do with the physical laws; it has to do with the initial conditions. (Assuming determinism).
And now Stephen should say that then the initial conditions should have been different, and that can only be when indeterminism is true.
Correct Stephen?
For me that is a minor point: I suppose Doug means “there is no physical law forbidding for me to have gone to Paris last weekend”. And that is true of course:
Of course it isn’t true, this is the main point of disagreement. If you went to Paris last weekend all else (exactly) the same, indeterminism would be true. The laws of nature would be different.
That’s physically impossible by definition. This is flat out wrong and what the main fuss is about.
The physical law has nothing to do with the initial conditions. A law is a regularity that holds for all times and places. Initial conditions are the way things were for an instant in time.
This doesn’t mean that all else exactly the same you would have been able to go to Paris last weekend. Only that your not having gone to Paris last weekend hasn’t got anything essentially to do with the physical laws; it has to do with the initial conditions. (Assuming determinism).
Ah, I think I see what you mean.
I think if the universe had a random first moment that can be determinism but if something were to happen later that was not determined, like GdB going to Paris, that would be indeterminism.
Edit: bearing in mind what GdB is using ‘all else the same’ to mean.
Of course it isn’t true, this is the main point of disagreement. If you went to Paris last weekend all else (exactly) the same, indeterminism would be true. The laws of nature would be different.
That’s physically impossible by definition. This is flat out wrong and what the main fuss is about.
Which laws of physics are then not adhered to, if I would have wanted to go to Paris?
I don’t think I should be expected to know. All I think I need to know is:
1) given the laws of nature you couldn’t want to go to Paris. (all else exactly the same)
2) If you had gone to Paris the laws of nature would have to have been different.
3) That would mean a contradiction or inconsistency between the way the laws are and the way they would have been.
In short, as a (feigned) soft determinist, who accepts the requisite auxiliary premises and principle of counterfactual logic, I am committed to the consequence that if I had done what I was able to do—raise my hand—then some law would have been broken.
Edit: And
Had I raised my hand, a law would have been broken beforehand. The course of events would have diverged from the actual course of events a little while before I raised my hand, and at the point of divergence there would have been a law-breaking event — a divergence miracle, as I have called it.
