Fine colour implies a unified relationship, in which each part is subordinate to the whole, and the transitions between them are felt to be as precious and beautiful as the colours themselves. In fact, the colours themselves must be continuously modified and broken as part of the transition.

The various parts of the body cannot be perceived as simple units and have no clear relationship to one another. In almost every detail the body is not the shape that art has led us to believe it should be.

The nude does not simply represent the body, but relates it, by analogy, to all structures that have become part of our imaginative experience.

It is often said that Leonardo drew so well because he knew about things; it is truer to say that he knew about things because he drew so well.

The difference between what we see and a sheet of white paper with a few thin lines on it is very great. Yet this abstraction is one which we seem to have adopted almost instinctively at an early stage in our development, not only in Neolithic graffiti but in early Egyptian drawings. And in spite of its abstract character, the outline is responsive to the least tremor of sensibility.

The illustrator is essentially a reporter: his subjects come from the outside, lit by a flash. A subject comes to the classical artist from inside, and when he discovers confirmation of it in the outside world he feels that it has been there all the time.

I wonder if a single thought that has helped forward the human spirit has ever been conceived or written down in an enormous room: except, perhaps, in the reading room of the British Museum.