From the Renaissance to the early twentieth century, “almost all painting had obeyed a convention: that of one-point perspective,” says Robert Hughes ( The Shock of the New , 16-7). Renaissance perspective has come to seem natural, just the way we actually see, but Hughes points out that it is actually “a form of abstraction,” a “generalization,” and “an ideal view, imagined as being seen by a one-eyed, motionless person who is clearly detached from what he sees.” It is the point of view of a God-like spectator, “who becomes the person on whom the whole world converges, the Unmoved Onlooker.”

What actually happens when we see something is quite different: “Look at an object: your eye is never still. It flickers, involuntarily restless, from side to side. Nor is your head still in relation to the object; every moment brings a fractional shift in its position, which results in a minuscule difference of aspect. The more you move, the bigger the shifts and differences become. If asked to, the brain can isolate a given view, frozen in time, but its experience of the world outside the eye is more like a mosaic than a perspective set up, a mosaic of multiple relationships, none of them . . . wholly fixed. Any sight is a sum of different glimpses.”

For all its abstraction, Cubism was in part a “proposition about the way we see,” about the way we actually see.