Are we made entirely of matter, like sticks and stones? Or do we have a soul-a nonphysical entity-where our mental lives take place?
The authors Eric T. Olson and Aaron Segal begin this accessible and wide-ranging debate by looking at the often-overlooked question of whether we appear in ordinary experience to be material things. Olson then argues that the dependence of our mental lives on the condition of our brains-the fact that general anesthesia causes complete unconsciousness, for instance-is best explained by saying that our mental lives are physical activities in our brains rather than nonphysical activities in the soul. Segal objects that this view is incompatible with two obvious and important facts about ourselves: that there is only one of you rather than trillions of almost identical beings now thinking your thoughts, and that we exist and remain conscious for more than an instant. These facts, he claims, are presupposed in our practical and moral judgments-but the