Fatalism and fundamentality

Here’s another argument for fatalism (from a conversation with Dean Zimmerman):

1. If P is true, then P is true in virtue of some Q which is fundamentally true.
2. If P is true in virtue of Q, and Q is necessarily true, then P is necessarily true.
3. Whatever is fundamentally true is necessarily true.
4. Therefore, if P is true then P is necessarily true.

Understand “P is necessarily true” as “P cannot be changed”. The conclusion is that whatever is a fact cannot be changed. Thus if there are facts about the future, then the future is fixed, so that no one can do anything about it.

The most suspicious premise of the three is the third—and indeed, I think it is false. But it does have some tug. I think the tug comes from a principle of sufficient reason (PSR):

1. If P is contingently true, then there is some further reason for why P is true.
2. If P is fundamentally true, then there is no further reason for why P is true.
3. So if P is fundamentally true, then P is necessarily true.

The full argument is more or less Leibniz’s. It is unsound, since this version of the PSR is false (though I think there is a good methodological principle in the neighborhood). But I won’t defend this claim right now.

For now I just want offer a sociological speculation: I suspect that something like this kind of reasoning is what drives people to views like presentism in order to rescue our freedom. Suppose that there are future things; why would their existence threaten our power to make it such that there be different things instead? Existing future things would threaten this freedom, if tenseless existence facts are fundamental (at least for fundamental sorts of things), and the fundamental facts could not be changed. The right thing to say to this is that (some) fundamental facts, including tenseless existence facts, can be changed.

(I heard a good joke today—Adam Elga attributed it to Steve Yablo: “Everyone talks about how people could have done otherwise. But why doesn’t anyone?”)