Recent developments in ethical discourse have brought the issue of the nature and development of character traits to the forefront of philosophical debate once again. This discussion tends to revolve around theories derived from Aristotle's account of character, and overlooks Sartre's existentialist alternative entirely. This accessible book presents an existentialist alternative to the currently dominant Aristotelian view of character. It will be of interest, therefore, to academics and graduate students concerned with virtue ethics and the theory of character as much as to those concerned with Sartre and existentialism in general. The book should set both the agenda and the standard for future discussions of Sartre's work within philosophical discourse.