The history of art cannot be properly understood without some reference to the history of science. In both we are studying the symbols by which man affirms his mental scheme, and these symbols, be they pictorial or mathematical, a fable or formula, will reflect the same changes.

Those who wish, in the interest of morality, to reduce Leonardo, that inexhaustible source of creative power, to a neutral or sexless agency, have a strange idea of doing service to his reputation.

Racial prejudices are indication of a disturbed and potentially unstable society.

A racist system inevitably destroys and damages human beings; it brutalizes and dehumanizes them, blacks and whites alike.

Only the bad artists of the nineteenth century were frightened by the invention of photography; the good ones all welcomed it and used it.

Art...must do something more than give pleasure: it should relate to our own life so as to increase our energy of spirit.

Leonardo is the Hamlet of art history whom each of us must recreate for himself.