On Periodization: What Does "Post-Duchamp" Mean?

When we speak of a post-Duchamp art world, we raise a particularly vexing periodization problem. Marcel Duchamp’s readymades, and the famous/infamous urinal titled Fountain in particular, have signaled that a sea change has occurred in the art world, which was not a change in styles but rather in aesthetic regimes, not a change in art movements but rather in art institutions, a change which, mutatis mutandis, is as radical as the passage from monarchy to republic, yet a change which art history books have not recorded yet, as such. Without addressing it in full, my paper recalls the steps that made me aware of this periodization problem.