Kind words do not cost much. They never blister the tongue or lips. They make other people good-natured. They also produce their own image on men's souls, and a beautiful image it is.

The last advance of reason is to recognize that it is surpassed by innumerable things; it is feeble if it cannot realize that.

People almost invariably arrive at their beliefs not on the basis of proof but on the basis of what they find attractive.

The heart has its order, the mind has its own, which uses principles and demonstrations. The heart has a different one. We do not prove that we ought to be loved by setting out in order the causes of love; that would be absurd.

We do not worry about being respected in towns through which we pass. But if we are going to remain in one for a certain time, we do worry. How long does this time have to be?

To deny, to believe, and to doubt well, are to a man what the race is to a horse.

The eternal silence of these infinite spaces frightens me.