[Nausea is] an onslaught on the "normal" or what is ordinarily taken for the normal. Unlike Sartre's later political novels, it is interesting because the attack is phenomenological, not political, an examination, that is, of the way things are.

What interests us about Roquentin, the protagonist of Nausea, in the present context is his conscious and deliberate alienation from those very aspects of French culture which by ordinary standards one would judge as eminently normal, for example, the apparently contented lives of the provincial bourgeoisie and the successful lives of the savants of the academy of science. (p. 368)

It is important to notice that Nausea is no ordinary free-thinking rationalistic-skeptical assault on the Catholic bourgeoisie. For Roquentin (and Sartre) have as little use for the opposition, the other triumphant sector of French society, the anti-clerical members of the academy, famous doctors, generals and politicians. (p. 369)

[What] are we to make of Sartre's and Roquentin's alienation?…

[Is] Sartre saying something of value about the condition of Western man in the twentieth century or perhaps about the human condition itself?

Or is Sartre's existentialism to be understood as only a way station in his transit from a bourgeois intellectual to a Marxist ideologue?

If Sartre is correct, then things have indeed been turned upsidedown. For in his novel the apparently well are sick and the apparently sick are onto the truth. But is the truth an unpleasant business we would do well to avoid? Roquentin thinks he knows something other people don't know, that he has made an unpleasant discovery which scarcely makes for happiness but allows him to live with an authenticity not attained by the happy bourgeoisie and the triumphant scientists. Anxiety, a sense of unreality, solitariness, loss of meaning, the very traits which we ordinarily think of as symptoms and signs of such and such a disorder are [in Nausea] set forth as appropriate responses to a revelation of the way things are and the way people really are. (p. 370)