The debate over free will often distils down to a question of determinism—indeterminism, hard or soft determinism, or something else. Poincare’s approach to the three-body problem is an apt metaphor to strengthen the deterministic side of the argument.
Quantum theory introduces aspects of indeterminism, but that doesn’t support the free will argument. Moreover, between quantum events, the universe is again deterministic. It’s simply been reset with the last exogenous quantum event.
Prima facia, Determinism and Chaos might seem strange bedfellows. And therein lies the rub. Chaos theory essentially tells us that even in a scenario of chaos, all possible outcomes can be calculated. They just must be calculated stepwise via numerical integration. Even this leaves us with estimations, as owing to Heisenberg’s Uncertainty Principle and the infinitude of slicing space, we can’t actually calculate the precise answer, although one exists.
My point is that not knowing what is being determined doesn’t invalidate the deterministic nature or process.
Philosophics 