Conventional thinking about the mind - dating back to Aristotle - envisions the emotions as being directed and, to a larger extent, determined by rational thought. This picture emerges from a model of the psyche as being divided into two components, one rational and the other irrational. The rational component is where we make our decisions, and when we act we do so on the basis of rational deliberation. Yet how is it that we sometimes perform rational acts in our best interests without having formally decided to do so? Nomy Arpaly argues that the conventional picture of rationality used by most philosophers and psychologists is fundamentally false and has little to do with how real human beings actually behave. Both common sense observations and psychology indicate that people act rationally without deliberation, and also often act irrationally with deliberation. She uses the example of Huckleberry Finn, who intuits that he should free Jim from slavery despite the recognition that it would be wrong to do so. By questioning our ability to understand our own motivations, Arpaly attempts to develop a more realistic conception of moral agency than the view currently being touted by contemporary etchicists and action theorists. Offering a fresh and provocative perspective on moral responsibility, autonomy, rationality and the self, Unprincipled Virtue breaks new ground in the highly contested issue of human agency.