Nihilism

[vulcanlogician]

I must be thinking of a different kind of nihilism then. I agree that determinism does not lead to moral nihilism. I was thinking of the more existential type.

ni·hil·ism
ˈnīəˌlizəm,ˈnēəˌlizəm/Submit
noun
the rejection of all religious and moral principles, often in the belief that life is meaningless.
PHILOSOPHY
extreme skepticism maintaining that nothing in the world has a real existence.

Well we have two definitions here, I was leaning toward the first with my comments. Besides, if one is generally a nihilist, he must also be a moral nihilist.

Seriously, though, forget doppelgangers, and assume Copenhagen interpretation of quantum mechanics (where things happen randomly), doesn't it mean that the future is at least partly random instead of determined fully by antecedents?

That's why contemporary metaphysics hardly considers hard determinism any longer. The replacement position is hard incompatibilism.

The incompatibilist position is: regardless of whether the universe is determined, there is no free will because all choices are caused by antecedent states and events. This allows for some indeterminism due to wave functions, but rejects the notion that randomness somehow brings free will into play. If there are non-determined events causing your actions, you are just as unfree as if determined events were.