Micro-Level Indeterminism and Macro-Level Determinism

Quantum mechanics, and the micro level indeterminacy it implies, is generally accepted by philosophers. So too naturalism on which macro states are held to supervene on micro states is now orthodox in the philosophy of mind and science. Still, in both fields it is frequently assumed that macro systems evolve deterministically. This assumption is commonly implicit and undefended, though at times it is made explicit and given minimal defense. In neither case is the incompatability of quantum indeterminacy, macro-micro dependence, and macro level determinism fully acknowledged. Even when incompatability is recognized, it is held that there is hope that quantum indeterminacy might be confined to micro levels. We argue that this is a vain hope. For certain standard quantum mechanical systems, micro indeterminism entails macro indeterminism unless macro states are effectively independent from micro states. This result obtains whether the relationship between supervenient and subvenient states is deterministic or indeterministic