Ayatollah So said:
Yes. Things would have to be different throughout all of time.
What I meant there is that, in order to evaluate a statement like "this water would dissolve salt if we poured it on some", or "WillJ could have worn a different sweater," we have to imagine a universe where conditions are different but the laws of nature are the same. The laws of nature should be the same because they are intimately related to the causal powers in question. Water has the power to dissolve salt; WillJ has the power to wear various sweaters. The fact that, in a universe with different natural laws, water might not dissolve salt, is irrelevant to the truth of the statement that water has the power to dissolve salt.
Now, if the laws of nature are deterministic, the only way conditions can be different is if they are different all through time. So then, that is what we have to imagine, if we want to defend either the claim that WillJ could have worn a red sweater, or the claim that he couldn't.
Makes sense, but doesn't that make the answer to this question:
So if I choose to wear a blue sweater today, the only reason I could have chosen a red sweater is because the initial conditions of the universe might have been different?
yes? Perhaps when you answered no earlier, you misunderstood what I was asking. To clarify, let me try to get what you're saying straight:
In a deterministic universe, each cause has only one possible effect. However, this does not mean that any effects in this universe, if it's deterministic, must have happened the way they did; things could be different if the initial condition of the universe were different, because obviously a different cause might, depending on its relevance, lead to a different effect.
Why? I think it's obvious that it often does matter whether you would make a different decision in different conditions: because, if you wouldn't, your action is irrational. If someone refuses to wear a red jacket even when that is the only way to avoid fatal hypothermia, the best explanation of their action is some sort of irrational compulsion. Which puts their freedom and their responsibility for the action in doubt.
First, let's take a step back and look at why many people are afraid of determinism. I'll give what I think is a decent example, although you might disagree:
Adolf Hitler was an evil man. Adolf Hitler was faced with his environment and decided to kill a bunch of Jews, among others. His evil, sick mind chose to kill people. He could have done otherwise, and you or I would most likely have done otherwise, but no, he didn't; he killed people.
Your average person would agree with this characterisation, but it no longer holds up in a deterministic universe. Some would even say that goodness and evilness couldn't exist in a deterministic universe.
If I'm not mistaken, you disregard this as unfounded, because Hitler would have done differently if conditions were different; it's not like he HAD to be evil. But I think that's beside the point. Proponents of free will don't actually argue that Hitler HAD to be evil in a deterministic universe. They see the free-will-universe as full of choices; Hitler is shown a choice of three doors and he
should have chosen 1 or 2, but he chose 3, and thus is evil. In a deterministic universe, Hitler is only shown door number 3 in the first place, so how can we fault him for choosing it? We can't; if we were to throw him in jail or something, we could only justify this by saying we were faulting his environment, not his actual self.
It's equally troublesome when we look at the future instead of the past. You might say that I
should give to charity some time this year. Or the American government
should turn more libertarian. But in a deterministic universe, argument of what should or should not happen is pointless; one thing is certain to happen anyway.
Edit: Note that I personally disagree with the "free will-ists" on the thing about Hitler, because Hitler's environment includes his brain, and even if his brain had no "options," there's nothing wrong with criticizing it if it's a plague to humanity. Arguing otherwise would be like saying we shouldn't be so harsh on hurricanes.
With the thing about the future, though, I must say that determinism
is a bit troublesome in that regard.