Onof, Christian J. "Sartre's Existentialism." INTERNET ENCYCLOPEDIA OF PHILOSOPHY Updated January 17, 2010.

The philosophical career of Jean Paul Sartre (1905-1980) focuses, in its first phase, upon the construction of a philosophy of existence known as existentialism. Sartre’s early works are characterized by a development of classic phenomenology, but his reflection diverges from Husserl’s on methodology, the conception of the self, and an interest in ethics. These points of divergence are the cornerstones of Sartre’s existential phenomenology, whose purpose is to understand human existence rather than the world as such. Adopting and adapting the methods of phenomenology, Sartre sets out to develop an ontological account of what it is to be human. The main features of this ontology are the groundlessness and radical freedom which characterize the human condition. These are contrasted with the unproblematic being of the world of things. Sartre’s substantial literary output adds dramatic expression to the always unstable co-existence of facts and freedom in an indifferent world. Sartre’s ontology is explained in his philosophical masterpiece, Being and Nothingness, where he defines two types of reality which lie beyond our conscious experience: the being of the object of consciousness and that of consciousness itself. The object of consciousness exists as “in-itself,” that is, in an independent and non-relational way. However, consciousness is always consciousness “of something,” so it is defined in relation to something else, and it is not possible to grasp it within a conscious experience: it exists as “for-itself.” An essential feature of consciousness is its negative power, by which we can experience “nothingness.” This power is also at work within the self, where it creates an intrinsic lack of self-identity. So the unity of the self is understood as a task for the for-itself rather than as a given. In order to ground itself, the self needs projects, which can be viewed as aspects of an individual’s fundamental project and motivated by a desire for “being” lying within the individual’s consciousness. The source of this project is a spontaneous original choice that depends on the individual’s freedom. However, self’s choice may lead to a project of self-deception such as bad faith, where one’s own real nature as for-itself is discarded to adopt that of the in-itself. Our only way to escape self-deception is authenticity, that is, choosing in a way which reveals the existence of the for-itself as both factual and transcendent. For Sartre, my proper exercise of freedom creates values that any other human being placed in my situation could experience, therefore each authentic project expresses a universal dimension in the singularity of a human life. After a brief summary of Sartre’s life, this article looks at the main themes characterizing Sartre’s early philosophical works. The ontology developed in Sartre’s main existential work, Being and Nothingness, will then be analysed. Finally, an overview is provided of the further development of existentialist themes in his later works. . . . Read the rest here: http://www.iep.utm.edu/sartre-ex/.