Eugene Marshall presents an original, systematic account of Spinoza's philosophy of mind, in which the mind is presented as an affective mechanism, one that, when rational, behaves as a spiritual automaton. The central feature of the account is a novel concept of consciousness, one that identifies consciousness with affectivity, a property of an idea paradigmatically but not exhaustively instantiated by those modes of thought Spinoza calls affects. Inadequate and adequate ideas come to consciousness, and thus impact our well-being and establish or disturb our happiness, only insofar as they...