Free will means you could've actually done otherwise in that exact moment. That only makes sense if there were multiple paths open to you.

But if multiple paths were actually possible, that's indeterminism, not determinism. Determinism means only one path was ever possible, you just didn't know which one ahead of time.

So how does "you have free will" survive next to "only one outcome was ever possible"? Can anyone explain it to me?

so my main issue with determinism is basically this: causal chains dont stay simple. they branch out like a tree, every physical event depends on an astronomical number of preceding interactions.

and if you trace those dependencies back far enough (or just look across a big enough system), you eventually hit quantum events. and under the standard interpretation of QM, those arent deterministic — the theory just gives you probabilities for outcomes, not a single fixed one.

so i keep wondering if determinism can even survive at large scales / over long timescales. sure macroscopic stuff looks deterministic in practice, but the causal history behind it eventually fans out into a massive number of microscopic quantum events.

which kinda makes we wonder if theres an inductive argument here — if the causal chain keeps branching and eventually bottoms out in genuinely indeterministic events, doesnt that mean the universe as a whole cant be strictly deterministic?

obviously this all hinges on whether quantum indeterminacy is actually fundamental vs just epistemic (i.e. we just dont have the info yet), and stuff like the Many-Worlds interpretation messes with the argument too since technically everything's still "deterministic" at the wavefunction level. but overall i think QM makes classical Laplacean determinism a lot harder to defend than people usually give it credit for.