Mind: A Brief Introduction (John R. Searle) / quote 25 of 138
Free will in a causally closed world
Do I genuinely have free will, or is it only an illusion? The question comes in a very sharp form for Descartes, because if my free will is a feature of my mind, how can it have any effect on the physical world, if the physical world is entirely determined? This problem is an extension of, but not the same as, the mind-body problem. For even if we have a solution to the mind-body problem, even if we can show how my thoughts and feelings can move my body, there is still the question, How is this consistent with the conception of physics of Descartes’ time that the physical world is a completely causally closed, deterministic system? Every event that happens in the physical world is determined by preceding physical events. So even if we could prove somehow that we have mental free will, it wouldn’t make any difference to the behavior of my body, because the behavior of my body is caused by the preceding states of my body and the rest of the physical universe. The problem of free will seems difficult for anyone, but it raises exceptional problems for someone who accepts dualism.