Make your faces so that they do not all have the same expression, as one sees with most painters, but give them different expression, according to age, complexion, and good or bad character.

There is no result in nature without a cause; understand the cause and you will have no need of the experiment.

The noblest pleasure is the joy of understanding.

Many have made a trade of delusions and false miracles, deceiving the stupid multitudes.

I abhor the supreme folly of those who blame the disciples of nature in defiance of those masters who were themselves her pupils

One painter ought never to imitate the manner of any other; because in that case he cannot be called the child of nature, but the grandchild. It is always best to have recourse to nature, which is replete with such abundance of objects, than to the productions of other masters, who learnt everything from her.

The first of all simple colours is White ... We shall set down White for the representative of light, without which no colour can be seen; Yellow for the earth; Green for water; Blue for air; Red for fire; and Black for total darkness.