Unlike politics and writing, art can hold in suspension different, even conflicting ideas, feelings and histories, without forcing us to choose between them. This capacity for incommensurability allows for experiences not socially recognised - as yet not named.

Writer, editor and academic Katy Siegel argues for painting as the most exciting form of this incommensurability - where abstraction and representation intersect and interfere with each other.  What is this secret history of modern painting, and why has rigid art criticism so long obscured it?