“He was always about the particular. The completely particular. This particular shape, this particular form, this particular color…everything is completely unique and particular.” So says Yve-Alain Bois, art historian and professor of art history at the Institute for Advanced Study in Princeton, about the celebrated, late artist Ellsworth Kelly. In this conversation, Bois shares what he learned about Kelly’s life, artistic process, and interest in the particular while working on the artist’s catalogue raisonné.