Abstract. René Descartes proposed an interactive dualism that posits an interaction between the mind of a human being and some of the matter in his or her brain. However, the classical physical theories that reigned during the eighteenth and nineteenth centuries are based exclusively on the material/physical part of Descartes' ontology, and they purport to give, in principle, a completely deterministic account of the physically described properties of nature, expressed exclusively in terms of these physically described properties themselves. Orthodox contemporary physical theory violates this condition in two separate ways. First, it injects random elements into the dynamics. Second, it requires psychophysical events, called Process 1 interventions by John von Neumann. Neither the content nor the timing of these events is determined, even statistically, by any known law. Orthodox quantum mechanics considers these events to be instigated by choices made by conscious agents. This quantum conception of the mind-brain connection allows many psychological and neuropsychological findings associated with the apparent physical effectiveness of our conscious volitional efforts to be explained in a causal and practically useful way. According to this quantum approach, conscious human beings are invested with degrees of freedom denied to the mechanistic automatons to which classical physics reduced us.