An arch consists of two weaknesses which, leaning one against the other, make a strength.

There are many occasions when the muscles that form the lips of the mouth move the lateral muscles that are joined to them, and there are an equal number of occasions when these lateral muscles move the lips of this mouth, replacing it where it cannot return of itself, because the function of muscle is to pull and not to push except in the case of the genitals and the tongue.

He who can copy can do.

O neglectful Nature, wherefore art thou thus partial, becoming to some of thy children a tender and benignant mother, to others a most cruel and ruthless stepmother? I see thy children given into slavery to others without ever receiving any benefit, and in lieu of any reward for the services they have done for them they are repaid by the severest punishments.

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.

Small rooms or dwellings discipline the mind, large ones weaken it.

We must doubt the certainty of everything which passes through the senses, but how much more ought we to doubt things contrary to the senses, such as the existence of God and the soul.