Being and Nothingness is considered Sartre's most important philosophical work,[11] and the most important non-fiction expression of his existentialism.[15] Christian existentialist Gabriel Marcel wrote that it was of "incontestable" importance and ranked among the most important contributions made to general philosophy. While Marcel noted the influence of Heidegger on "the form at least" of Being and Nothingness, he also observed that Sartre diverged from the views expressed by Heidegger in Being and Time (1927) in important ways, and that Sartre's contributions were original. Marcel considered Sartre's analysis of bad faith "one of the most outstanding and solid" parts of Being and Nothingness, writing that it prevented Sartre's arguments from being purely abstract. Marcel saw one of the most important merits of the work to be to show "that a form of metaphysics which denies or refuses grace inevitably ends by setting up in front of us the image of an atrophied and contradictory world where the better part of ourselves is finally unable to recognise itself".[16]
The philosopher Jean Wahl criticized Sartre's arguments about the topic of "nothing".[17] The philosopher Frederick Copleston described Sartre's view that all human actions are the result of free choice as "highly implausible", though he noted that Sartre had ways of defending his position.[18] He also expressed sympathy for Marcel's criticism of Sartre, and described Sartre's view of freedom as both "nihilistic" and possibly inconsistent with some of Sartre's other views.[19] The philosopher A. J. Ayer wrote that, apart from some psychological insights, the book was "a pretentious metaphysical thesis" and "principally an exercise in misusing the verb 'to be'".[20]
The author Susan Sontag praised Sartre's discussions of the body and concrete relations with others. She identified them as part of a French tradition of serious thought about problems of fundamental importance.[21] The literary scholar John B. Vickery wrote that Being and Nothingness resembles Sir James George Frazer's The Golden Bough (1890) in the way its author "merges psychology and the concrete sense of fiction", although he considered it less readable than Frazer's work.[22] The philosopher Iris Murdoch compared Being and Nothingness to Gilbert Ryle's The Concept of Mind (1949). She maintained that continental philosophy shares the same general orientation as English analytic philosophy.[23] According to the philosopher Steven Crowell, Being and Nothingness had come to be seen as outdated by Sartre's death in 1980, since its emphasis on consciousness associated with "the subjectivism and psychologism that structuralism and analytic philosophy had finally laid to rest".[24]
The philosopher David Pears criticized Sartre's critique of Freud, describing it as complex but imprecisely formulated and open to potential objections.[25] The philosopher Thomas Baldwin described Being and Nothingness as a work of pessimism. He wrote that Sartre's argument that Freud's theory of repression is internally flawed is based on a misunderstanding of Freud, and that Sartre's attempts to adapt Freud's ideas are of greater interest.[11] The director Richard Eyre recalled that Being and Nothingness was popular among British students in the 1960s, but suggests that among them the work usually went unread.[26]
Several authors, including the sociologist Murray S, Davis,[27] the philosophers Roger Scruton and Maxine Sheets-Johnstone,[28][29] and the physician Frank Gonzalez-Crussi,[30] have praised Sartre for his contributions to the philosophy of sex. Davis credited Sartre with being the first author to present a phenomenological analysis of sex.[27] Scruton credited Sartre with providing "perhaps the most acute philosophical analysis" of sexual desire and correctly arguing that treating sexual desire as equivalent to appetite ignores "the interpersonal component of human sexual responses." He described Sartre's reflections on le visqueux as "celebrated".[28] He has also credited Sartre with providing a "stunning apology for sado-masochism",[31] and characterized Being and Nothingness as a "great work of post-Christian theology".[32] Gonzalez-Crussi credited Sartre with recognizing that it is incorrect to equate sexual desire with desire for sexual acts.[30] Sheets-Johnstone believed Sartre presented a subtle analysis of human sexuality. She praised his understanding of desire in general and suggested that his views about the subject anticipated those of the philosopher Michel Foucault. She believed that his views contained both significant truth and internal contradictions. She suggested that despite his criticism of Freud, his views about women and female sexuality were in some ways similar to Freud's.[29] Naomi Greene, arguing that there is a "distaste for sexuality" in Sartre's work, identifies a clear "anti-sexual bias" present in Being and Nothingness.[33]
