What exactly are the reasons we do things, and how are they related to the resulting actions? Bittner explores this question and proposes an answer: a reason is a response to that state of affairs. This is actually in complete opposition to the broad consensus in Western philosophy that reasons are items, or configurations of items in the mind (i.e psychological states). That consensus is firmly rejected by Bittner, who tries to retrieve a thoroughly worldly understanding of reasons. Elegantly written, this work is a substantial contribution to the fields of rationality, ethics, and action theory.