Psychotropic agents have been effective for the treatment of the emotional, and cognitive symptoms of serious psychiatric disorders. At the same time, the availability of such agents raises questions about the appropriate use of what might be termed 'smart pills', 'happy pills', or 'pep pills'. This volume argues that developments in modern psychopharmacology raise a range of important philosophical questions, and may ultimately change the way we think about ourselves. It provides a framework for addressing important philosophical issues in psychiatry and psychopharmacology. The approach is a naturalistic one, drawing on theory and data from modern cognitive-affective neuroscience and attempts to address objective and subjective aspects of psychiatric disorders, to integrate our knowledge of mechanisms and meanings, and to provide a balanced view of the good and the bad of psychotropics.