Being and Nothingness it has been suggested that it usually went unread by them. Sartre's reflections on slime ("le visqueux") have been described as celebrated. Sartre's existentialism shares its philosophical starting point with René Descartes: The first thing we can be aware of is our existence, even when doubting everything else (Cogito ergo sum). In "Nausea", the main character's feeling of dizziness towards his own existence is induced by things, not thinking. This dizziness occurs "in the face of one's freedom and responsibility for giving a meaning to reality". As an important break with Descartes, Sartre rejects the "primacy of knowledge", as summed
Cogito, ergo sum and that "I" know what "thinking" is. He suggested a more appropriate phrase would be "it thinks" wherein the "it" could be an impersonal subject as in the sentence "It is raining." The Danish philosopher Søren Kierkegaard calls the phrase a tautology in his "Concluding Unscientific Postscript". He argues that the "cogito" already presupposes the existence of "I", and therefore concluding with existence is logically trivial. Kierkegaard's argument can be made clearer if one extracts the premise "I think" into the premises "'x' thinks" and "I am that 'x'", where "x" is used as a placeholder in order to disambiguate