To Leonardo a landscape, like a human being, was part of a vast machine, to be understood part by part and, if possible, in the whole. Rocks were not… - Kenneth Clark

Changes in the structure of society are not brought about solely by massive engines of doctrine. The first flash of insight which persuades human beings to change their basic assumptions is usually contained in a few phrases.

Everybody who writes about Blake begins by saying that he was a visionary. It is a vague term. All artists, even the most realistic, start with some kind of vision - that is what leads them to select what they need from the infinite diversity of appearances.

The convention by which the great events in biblical or secular history could be enacted only by magnificent physical specimens, handsome and well-groomed, went on for a long time — till the middle of the nineteenth century. Only a very few artists — perhaps only Rembrandt and Caravaggio in the first rank — were independent enough to stand against it. And I think that this convention, which was an element in the so-called grand manner, became a deadening influence on the European mind. It deadened our sense of truth, even our sense of moral responsibility.