Welshon argues for a new interpretation of Nietzsche's metapsychology and philosophy of mind. Rather than rehearsing Nietzsche's criticisms of souls and religious and philosophical uses of souls and subjects yet again, Welshon starts from the idea that Nietzsche is interested in unpacking the view that the subject is a naturalized phenomenon, both embodied and embedded in a larger natural and social environment and dynamically engaged with that larger environment. He shows that this view of the subject has significant textual support in Nietzsche's published books and unpublished notes. Of particular interest to readers are his discussion of drives as the yeoman psychological category of explanation, his discussion of Nietzsche's thoughts about consciousness, and his defense of Nietzsche's views against criticism that they (i) cannot make sense of psychological causation; (ii) are inconsistent with contemporary evolutionary theory; and (iii) are inconsistent with contemporary cognitive science.