Mallarmé saw writing as a “mad game” [“ce jeu insensé de l’écriture”]. Following Blanchot following Mallarmé, Foucault equaled literature’s writing again with “madness [folie]” and then both with the enigmatic thought of an “absence of work [absence d’œuvre].” By bringing together close readings and references to clinical experience, this course hopes to show that writing lies at the heart of psychoanalysis. We will also ask what share of the “mad game” is written into this heart. In Freud we will trace a poetics that secretly informs the careful constructions of his concepts and theoretical compositions. With Schreber we will analyze a drive to find a formula for the mad experience, a drive that does not only inform his own Memoirs of my Nervous Illness but whose transference can be read in founding texts of psychoanalytic writing on psychosis. In Lacan we will comment on his intention to force a reduction of psychoanalytic discourse to such an extent that it may yield the letters of a “writing of the real.” By elaborating these three moments of writing – (poetic) construction, (mad) formalization, (literal) reduction – we will ask what they have to do with the “sexual” – the word, the concept, the thing, and its metonymies (transference, libido, drive, affect, Eros) – with the “sexual”, this other “heart” of psychoanalysis.