I love those who can smile in trouble.

Experience is a truer guide than the words of others.

We know more about the movement of celestial bodies than about the soil underfoot.

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.

Constancy does not begin, but is that which perseveres.

Study me, reader, if you delight in me, because on very few occasions shall I return to the world, and because the patience for this profession is found in very few, and only in those who wish to compose things anew. Come, oh men, to see the miracles that such studies will disclose to nature.

It is no small benefit on finding oneself in bed in the dark to go over again in the imagination the main lines of the forms previously studied, or other noteworthy things conceived by ingenious speculation.