Sartre begins Nausea with a fictional “Editors’ Note.” This section frames the remainder of the novel as a set of diaries found in the papers of a man named Antoine Roquentin; the subsequent pages are undated but were likely written at “the beginning of January, 1932.” Antoine, the editors suggest, had just returned from “travelling through Central Europe, North Africa and the Far East” and at the time of writing the diaries was living in the town of Bouville, France in order to finish his historical research on the Marquis de Rollebon. The editors give no further information about Antoine’s whereabouts (or who they themselves are), and we immediately move into the diaries.
Antoine begins his diaries by stating his intention to “[k]eep a diary to see clearly—” and to track and classify his perceptions and the changes around him. He then attempts to describe the box holding his ink-bottle but fails to find anything to say. He also can’t accurately describe a recent Saturday, when an event caused him disgust. Still, he begins telling the story of that Saturday: he had been watching children skip stones on the surface of the sea and wanted to join in. When he did, the children laughed at him, and he was overcome with a strange feeling, one which he feels is related to the stone or the sea, although he is unsure which of the two is the cause. Later in the evening, at 10:30, he writes that it may have simply been “a passing moment of madness”; looking out the window, he observes people exiting the nearby train station and thinks of a man who comes each week to the hotel Antoine lives in. He’s thrilled by the familiar sound of him coming upstairs and decides to go to bed. The journal trails off mysteriously with the phrase “In one case only it might be interesting to keep a diary: it would be if…”
The dated pages begin on Monday, 29 January, 1932. Antoine writes that “[s]omething has happened to” him and describes this event as something that came on gradually, like an illness. Though he concedes that historians aren’t usually much good at minute psychological analysis, he narrates some of the strange experiences he’s had: there is something different about his hands or, possibly, the objects his hands pick up; he couldn’t recognize someone called “the Self-Taught Man,” who the “Editors” name as Ogier P; there are strange noises in the street. He decides he must have changed and remembers when a friend, Mercier, asked him to join him on an archeological mission to Bengal. Antoine, then in Indo-China and staring at “a little Khmer statuette on a green carpet,” felt a moment of disgust, denied Mercier’s offer, and decided to return to France.
The next day, Antoine works in the library, finishing his history of the Marquis de Rollebon, except for his final revisions. He writes while eating at the Café Mably and pondering his loneliness. His primary interactions seem to be with the Self-Taught Man and Françoise, who operates the “Railman’s Rendezvous” and with whom Antoine is having sex. He also thinks about his ex-lover, Anny, and the glass of beer before him, which he has “been avoiding looking at.” He remembers a disabled, seemingly homeless man whose loneliness frightened him as a child, and he realizes that he himself is “disturbed at being alone.” He reveals that he has been lying by suggesting that “nothing new” has happened. This segues into a discussion of his inability to pick up a paper found on the ground, followed by a tactile description of the pleasure he normally finds in touching objects like rags or damp paper.
In Thursday’s entry, Antoine begins by discussing a conversation he overheard about relationship troubles between Lucie, a maid, and the hotel’s proprietress. In the afternoon, he transcribes quotes from historical sources that he’s using in his research; we learn his research has been going on for at least ten years. Antoine notes that he has a lot of source material about the Marquis he is studying but no sense of the Marquis himself; he reflects on the fact that now the book he’s writing interests him more than the actual historical figure of the Marquis de Rollebon. He knows the Marquis was involved in the assassination of Paul II but finding proof of this seems impossible. The work of history begins to feel purely imaginative, more like novel-writing than transposing facts.
The next day, he consults more sources about the Marquis’ involved in the assassination. He quotes historians who attest to the Marquis’ ability to lie and mimic, but Antoine recalls that the Marquis had an alibi. Becoming bored, Antoine looks into “a trap”—the mirror. He looks at his face and paints his red hair and facial features in acute detail, although he feels unable to get a grasp on himself. Waking from his hypnosis-like state, he quotes an author describing the Marquis’ face. The quote ends thus: “‘[the Marquis] looked like a Roquefort cheese.’”
At 5:30 that day, Antoine has another attack of nausea. This attack begins when he discovers the patroness of the café isn’t there when he arrives. Sexually disappointed, he observes the waitress, Madeleine, the men playing cards near him, and the patroness’ cousin, whose purple suspenders disturb him. Still nauseous, Antoine asks Madeleine to play him "Some of These Days," a blues record and one of Antoine’s favorites. Madeleine plays the record. While Antoine considers death and birth, he listens to the music and eavesdrops on the men playing cards. His nausea eases. Soon he leaves, wandering the streets until he sees an old crumpled poster where only the word “purȃtre” (pure-ish) is legible. The avenue Noir seems inhuman, and walking down it, he encounters the maid, Lucie, who “seems turned to stone” after a man verbally abuses her. The entry ends with Antoine ignoring her.
The next Thursday, Antoine has completed two hours of work. He takes a break to smoke a pipe and thinks about the statue of “Gustave Impetraz” before him, a school inspector and writer. Antoine remembers reading his encyclopedia entry and describes the statue’s face. Soon the Self-Taught Man interrupts his contemplations, and the two men go inside to work. Finding Eugenie Grandet open to page 27, Antoine begins reading there, afraid of beginning on the first page. The Self-Taught Man’s reading patterns seem to make no sense until Antoine realizes that he’s reading through the library alphabetically; at this point, he’s at “L.”
The next day, at 3:00, Antoine is looking out the window at an old woman. His thoughts, compounded by looking at himself in the mirror, make him sick. He turns to memories from “two years ago” of visiting “the East”: Meknes (in Morocco), Russia, Japan. He admits that he is “inventing all this” (the memory) “to make out a case.” It quickly becomes unclear how many of his memories—and his stories—are fictionalized. Once again, the Self-Taught Man interrupts his thoughts. We discover that Antoine has agreed to show the Self-Taught Man images from his travels. They discuss adventure, differences in cultural customs, and the benefits of travel-induced change; Antoine remembers the Khmer statuette again.
After forcing the Self-Taught Man to leave (but not without stuffing his pockets with postcards and pictures), Antoine debates whether or not it matters if he’s really had adventures. He feels he hasn’t had them and thinks about the need for “real beginnings.” Likening these beginnings to the opening of "Some of These Days," Antoine considers the interrelatedness of a “real beginning” and being drawn towards death. Reflections on music are mixed in with memories of women in other cities, and he considers the sweet possibility of him becoming the subject of the jazz melody sung by the black woman who sings "Some of These Days." Yet rather than reach a satisfying conclusory thought, Antoine responds to the unnameable idea disturbing him: “But Why? WHY?”
The editorial note begins Nausea by allowing readers to understand that the book will take the form of a series of diary entries, all of which will be told from the first-person perspective of Antoine Roquentin. This form helps to bolster the novel’s existentialist themes. Existentialism was a philosophy spearheaded by Sartre, which places emphasis on the individual subjectivity of human beings. As suggested in the opening of his Being and Nothingness (the book considered Sartre’s primary statement of existentialism), existentialist philosophers thought it was necessary to study the way things appeared subjectively to human consciousness, and the use of a first-person, diary form centers the novel around how the events of the novel appear within Antoine’s mind.
This focus on individual consciousness is further emphasized by the novel’s narrative style. Once we enter Antoine’s diaries, the novel uses a stream-of-consciousness mode of narration. Typical of modernist writing, stream-of-consciousness writing follows the smallest details in a person’s perception. Instead of moving from one large narrative moment to another, Antoine traces his minor changes of emotions, describes his aimless wandering from street to street, and explains his thought processes in detail. This, at times, gives the novel a similar feeling to a philosophical treatise, in which we follow Antoine’s logic as he analyses the world around him.
The first section of Antoine’s diaries, the undated pages, also establish the titular theme of the book. In Nausea, this feeling seems to be largely triggered by objects, such as the stone at the beginning or the glass of beer at the Café. This nausea may find some explanation in Sartre’s wider writings. He saw humans as things which were both "in-itself" (non-conscious or objective) and "for-itself" (conscious subjects), but he also thought these two ways of being were irreducible. One couldn’t reconcile one’s inert, passive existence with one’s active consciousness. This makes human existence a fundamental paradox, as we are unable to make consistent these two kinds of being. Most people, he thought, did not fully acknowledge this ambiguity, and he referred to these people as those living “in bad faith.”
Antoine’s growing realization that he is in a world of things and is both a thing and a consciousness may then be one reason why looking at his own face causes him nausea: in the mirror, he confronts himself as something both objective and subjective. The nausea becomes more and more overwhelming for both Antoine and the reader as the book goes on, largely because Sartre repeatedly returns to Antoine’s attacks. The persistent attacks then give the novel a visceral, bodily atmosphere that is only further emphasized by Sartre’s grotesque imagery.
Another theme developed in this first section is the blurry boundary between history and fiction. Antoine struggles to get a grip on the Marquis de Rollebon as a person, despite the large number of documents available to him. In the same way, we as readers struggle to get a grip on Antoine, especially when he explicitly states that he’s “inventing all this” regarding his memories and travels. Throughout the novel, we can never be sure how much of his past (or the journals themselves) are factual and fiction. Antoine then might be considered an unreliable narrator, as his stories and dates don’t always add up. Even further, his tendency towards inventing and lying might make us question the truth of “history” or “memory” in general.