If one shed tears, they must be shed on one's pillow.

Absolute liberty is absence of restraint; responsibility is restraint; therefore, the ideally free individual is responsible to himself.

Every one must bear his own universe, and most persons are moderately interested in learning how their neighbors have managed to carry theirs.

The American man is a very simple and cheap mechanism. The American woman I find a complicated and expensive one. Contrasts of feminine types are possible. I am not absolutely sure that there is more than one American man.

Just as the French of the nineteenth century invested their surplus capital in a railway-system in the belief that they would makemoney by it in this life, in the thirteenth they trusted their money to the Queen of Heaven because of their belief in her power to repay it with interest in the life to come.

Nothing is more tiresome than a superannuated pedagogue.

[P]olitical and social and scientific values ... should be correlated in some relation of movement that could be expressed in mathematics, nor did one care in the least that all the world said it could not be done, or that one knew not enough mathematics even to figure a formula beyond the schoolboy s=(1/2)gt2. If Kepler and Newton could take liberties with the sun and moon, an obscure person ... could take liberties with Congress, and venture to multiply its attraction into the square of its time. He had only to find a value, even infinitesimal, for its attraction.