Manuscripts and notes by Michel Foucault on the visual arts recently deposited at the Bibliothèque Nationale reveal a reliance on canonical oil paintings by the ‘old masters’; a respect for the primary sources in the history of European art; an understanding of the necessity of research in both literary and visual sources, particularly self-portraits; and a sense of the value that a certain philosophical milieu – beginning with Sade and Nietzsche and expanding to his near contemporaries, Bataille, Blanchot, and Klossowski (...) – could offer to an understanding of paintings. The essay argues that Pierre Klossowski’s monumental drawing La Nef des fous (1990) provides an essential key for understanding the place of Hieronymus Bosch’s painting of the same title in History of Madness and the centrality of theories of similitude to Foucault’s thinking about visuality ca. 1960–74. The later significance of the figure of the artist for Foucault can be traced to these earlier writings on painting and madness. (shrink)