A life well used procures a happy death.

First study the science, and then practice the art which is born of that science.

Many will think they may reasonably blame me by alleging that my proofs are opposed to the authority of certain men held in the highest reverence by their inexperienced judgments; not considering that my works are the issue of pure and simple experience.

A good painter has two main objects to paint, man and the intention of his soul. The former is easy, the latter hard as he has to represent it by the attitude and movement of the limbs.

In the days of thy youth seek to obtain that which shall compensate the losses of thy old age.

Putting your hand into a river, you simultaneously touch the last of what is passing and the first of what is coming.

True and great love springs out of great knowledge, and where you know little you can love but little or not at all.