Damasio brings some some fascinating cases to bear on one of the oldest problems in philosophy and psychology. It's a good read and an important subject. It would be a mistake, however, to think that "Descartes' error" was just now being pointed out. In fact, practically no contemporary philosopher worth his or her salt subscribes to the Cartesian two-substance theory of body and mind. In his 1949 masterpiece, The Concept of Mind, Gilbert Ryle argued that Descartes' view was fatally flawed (and he wasn't really the first to point this out, either), and called it the "ghost in the machine" view of the body/mind relationship. If you get right down to it, Descartes himself would agree with Damasio that the emotions are not radically different kinds of things from the reasoning faculties, since he believed that experiencing an emotion was simply another mode of thought, just as drawing an inference is a mode of thought. But Descartes must be used to being a whipping boy by now, 350 years after his death; and the historical perspective aside, Damasio's book is an excellent contribution to scholarship on the effects of emotion on rationality.