Being and Nothingness: An Essay on Phenomenological Ontology, sometimes published with the subtitle A Phenomenological Essay on Ontology, is a 1943 book by the philosopher Jean-Paul Sartre. In the book, Sartre develops a philosophical account in support of his existentialism, dealing with topics such as consciousness, perception, social philosophy, self-deception, the existence of "nothingness", psychoanalysis, and the question of free will.

Phenomenology of Perception is a 1945 book about perception by the French philosopher Maurice Merleau-Ponty, in which the author expounds his thesis of "the primacy of perception". The work established Merleau-Ponty as the pre-eminent philosopher of the body, and is considered a major statement of French existentialism.