The concept of "bad faith" in Sartre's philosophyJean-Paul Sartre was a French philosopher, a versatile thinker and writer. He is known today for two systematic and extraordinary works in the field of philosophy. In addition to these two phenomenal works – “Being and Nothingness” and “Critique of Dialectical Reason” – Sartre developed some shorter philosophical versions including; several screenplays, plays and novels; essays on art and literary criticism; short stories; an autobiography; dozens of journalistic and political writings; and original and distinctive biographies of several writers. In the post-World War II period, Sartre is considered one of the most famous philosophers with a large audience around the world. Sartre was the key representative of “existentialism”: an important philosophical movement that continued to dominate intellectual life especially in Europe in the decades of the 1940s and 1950s. Understanding the concept of bad faith means understanding Sartre's existentialist philosophy. The concept of bad faith forms the basis of his moral psychology. Furthermore, bad faith continued to remain the main theme of all of Sartre's philosophical works. The concept emphasizes that bad faith, like all of our attitudes, determines how the world and each person in it appears. Bad faith shapes all of our beliefs, opinions, and actions specifically as agents in the world. In this context, the article will discuss the concept of bad faith as included in Sartre's philosophy. Sartre - in 'Being and Nothingness' - explains human relationships fundamentally as an opposition between the Other and the Self. The Other interferes in the world of consciousness which is confronted with anguished, fearful and shameful identification... middle of the paper... justified belief and does not take into account any future evidence (Fox, 2008). The article discussed in detail the concept of bad faith in Sartre's philosophy. Jean-Paul Sartre was a French philosopher, a versatile thinker and writer. The concept of bad faith forms the basis of his moral psychology. The concept emphasizes that bad faith, like all of our attitudes, determines how the world and each person in it appears. Works Cited Detmer, D. (1988). Freedom as a Value: A Critique of Jean-Paul Sartre's Ethical Theory.Open CourtFisher, T. (2009). Bad faith and the actor: onto-mimetology from a Sartrean point of view. Sartre Studies International, 15(1):74-91Fox, M.A. (2008). The notable existentialists. Books about humanityWebber, J. (2010). Read Sartre: Phenomenology and Existentialism. Taylor and Francesco