Without man and his potential for moral progress, the whole of reality would be a mere wilderness, a thing in vain, and have no final purpose.

There is something splendid about innocence; but what is bad about it, in turn, is that it cannot protect itself very well and is easily seduced.

In every department of physical science there is only so much science, properly so-called, as there is mathematics.

Enlightenment is man's leaving his self-caused immaturity. Immaturity is the incapacity to use one's intelligence without the guidance of another. Such immaturity is self-caused if it is not caused by lack of intelligence, but by lack of determination and courage to use one's intelligence without being guided by another. Sapere Aude! Have the courage to use your own intelligence! is therefore the motto of the enlightenment.

The yellow Indians do have a meagre talent. The Negroes are far below them, and at the lowest point are a part of the American people.

With men, the state of nature is not a state of peace, but war.

Act so as to use humanity, yourself and others, always as an end and never as a means to an end.