Evidently one cannot look for long at the Last Supper without ceasing to study it as a composition, and beginning to speak of it as a drama. It is the most literary of all great pictures, one of the few of which the effect may largely be conveyed - can even be enhanced - by description.

Great works of art can be produced in barbarous societies - in fact the very narrowness of primitive society gives their ornamental art a peculiar concentration and vitality. At some time in the ninth century one could have looked down the Seine and seen the prow of a Viking ship coming up the river. Looked at today in the British Museum, it is a powerful work of art; but to the mother of a family trying to settle down in her little hut, it would have seemed less agreeable - as menacing to her civilisation as the periscope of a nuclear submarine.

Only the bad artists of the nineteenth century were frightened by the invention of photography; the good ones all welcomed it and used it. Degas liked it not only because it provided an accurate record, but because the snapshot showed him a means of escape from the classical rules of design. Through it he learnt to make a composition without the use of formal symmetry.

I believe in courtesy, the ritual by which we avoid hurting other people's feelings by satisfying our own egos.

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 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.

We can destroy ourselves by cynicism and disillusion, just as effectively as by bombs.