Jason Gaiger, Duchamp, Man Ray, Picabia, Incidental and Integral Beauty: Duchamp, Danto and the Intractable Avant-Garde  It is widely accepted that the radical avant-garde movements of the early twentieth century abjured beauty, thereby effecting a decisive break with the art of the past. Duchamp is accorded a leading role in this process insofar as he rejected the satisfactions of ‘retinal pleasure’ in favour of an art of ideas.