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 ("If I am mistaken, I am") (book XI, 26), and also anticipates modern refutations of the concept. Furthermore, in the "Enchiridion" Augustine attempts to refute skepticism by stating, "[B]y not positively affirming that they are alive, the skeptics ward off the appearance of error in themselves, yet they do make errors simply by showing themselves alive; one cannot err who is not alive. That we live is therefore not only true, but it is altogether certain as well" (Chapter 7 section 20). In 1640 correspondence, Descartes thanked two colleagues for drawing his attention to Augustine and notes similarity and difference.