Determinism means that the state of the universe at present time completely determine everything in the future.
Eternalism said that everything in the future and the past is already there.
Crucially, eternalism does not said that the future is determined by the past!!! In other word, if some super computer being is given a complete specification of the current state of the universe (at current time, whatever that means), there are no ways to predict the all the future. In fact, eternalism does not even said that there are “present” or “future” time at all. But determinism still believe in the idea of present or future.
Latest Answers