Reasons are not causes. Inhalation of propane beyond inhalation of oxygen was the cause of John's death. The reason for John's death was his desire to commit suicide. The "desire (reason) to commit suicide" results in innumerably diverse states of affairs, but an innumerable diversity of results is not a sign of a true cause-effect relationship. Nor does it follow from "wanting to kill oneself" that one will 1) walk over, 2) touch the oven, 3) turn on the gas, etc. But inhalation of propane beyond intake of oxygen is a cause of human death. Reasons are not causes, therefore the will is free.