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

Have patience awhile; slanders are not long-lived. Truth is the child of time; erelong she shall appear to vindicate thee.

Reason can never prove the existence of God.

If man makes himself a worm he must not complain when he is trodden on.

Philosophy stands in need of a science which shall determine the possibility, principles, and extent of human knowledge à priori.

There will always be some people who think for themselves, even among the self-appointed guardians of the great mass who, after having thrown off the yoke of immaturity themselves, will spread about them the spirit of a reasonable estimate of their own value and of the need for every man to think for himself.

It is by his activities and not by enjoyment that man feels he is alive. In idleness we not only feel that life is fleeting, but we also feel lifeless.