Nausea

Sartre's first novel, written as the diary of Antoine Roquentin, a solitary scholar living in the provincial seaport of Bouville, where he is writing a biography of an eighteenth-century adventurer, the Marquis de Rollebon. Roquentin is overtaken by a strange sickness: ordinary things, a pebble on the beach, a glass of beer, his own hand, seem to lose their names and uses and press on him in their sheer existence. The crisis peaks in a public park, where he stares at the root of a chestnut tree and grasps that existence is contingent: things are simply there, without reason or necessity, superfluous. Around this he records the town's respectable citizens and their portraits in the museum, the Self-Taught Man who is reading through the library in alphabetical order and preaches humanism, and a meeting with his former lover Anny. A jazz song on a gramophone record offers a glimpse of something free from contingency. The novel stages ideas Sartre later developed in Being and Nothingness.

It is the most vivid way to feel, rather than just understand, the existentialist claim that existence has no built-in reason or meaning.