Going by the titles of his books, Deleuze has proposed two philosophical concepts for styles from art history: expressionism and baroque. It is true that he discusses many other notions from the history of style, but these are the only ones that are truly made to ‘exist in themselves’. Or might there be a third, buried like a wedge between its two neighboring concepts? Although the notion of mannerism recurs in several of Deleuze’s writings, it is never developed in any systematic way. Even in The Fold. Leibniz and the Baroque mannerism stays entirely subordinate to ‘its working relation with the baroque’. It is only in his last course at Vincennes, in which he draws a parallel between Michelangelo and Leibniz, that Deleuze wonders whether we possess ‘the means to give a certain philosophical consistency to the concept of mannerism’, which in addition he labels ‘the most evident, the most certain theme of our investigations this year’. My aim is to render mannerism separable again from the baroque. This will be done by putting attempts in art history and art criticism to give a definition of mannerism in interference with a close-reading of key passages in Deleuze’s work, especially from The Fold and Francis Bacon. The Logic of Sensation. From the concept of the ‘Figure’ developed in the latter, I will distillate an initial concept of mannerism as an art that proceeds by way of diagrammatic deformation. Subsequently, I will compare this concept to Deleuze’s concept of the Baroque (the ‘fold taken to infinity’) and argue that, while the baroque pushes the anti-classical and revolutionary ‘catastrophe’ of mannerism to the extreme, it simultaneously and paradoxically forms a conservative and restorative reaction to it. It is by exploring mannerism’s ‘very particular relations’ with the baroque, finally, that we can also discover in mannerism a precursor to 20 th century modernism and in Deleuze’s modernist allegiance several neo-mannerist tendencies. Mannerism, Baroque, and Modernism: Deleuze and the Essence of Art Sjoerd van Tuinen, 2012, Erasmus University Rotterdam