Why do human beings move? In this lucid portrayal of human behavior, Fred Dretske provides an original account of the way reasons function in the causal explanation of behavior. Biological science investigates what makes our bodies move in the way they do. Psychology is interested in why persons -- agents with reasons -- move in the way they do. Dretske attempts to reconcile these different points of view by showing how reasons operate in a world of causes. He reveals in detail how the character of our inner states -- what we believe, desire, and intend -- determines what we do.

"[An] important book, as intelligent and challenging as readers of Fred Dretske's earlier works will expect... Dretske is well-informed in cognitive science, evolutionary biology and animal behavior, and one of the pleasures of his book is the range of examples which inform the arguments.... His careful, nontechnical presentation will be a focus for discussion in the philosophy of mind."
-- Christopher Hookway, Times Higher Education Supplement

Fred Dretske is Professor of Philosophy at Stanford University.