The wish to talk to God is absurd. We cannot talk to one we cannot comprehend — and we cannot comprehend God; we can only believe in Him.

The hand is the visible part of the brain.

The ideal of the supreme being is nothing but a regulative principle of reason which directs us to look upon all connection in the world as if it originated from an all-sufficient necessary cause.

Enthusiasm is always connected with the senses, whatever be the object that excites it. The true strength of virtue is serenity of mind, combined with a deliberate and steadfast determination to execute her laws. That is the healthful condition of the moral life; on the other hand, enthusiasm, even when excited by representations of goodness, is a brilliant but feverish glow which leaves only exhaustion and languor behind.

Human beings are never to be treated as a means but always as ends.

By a lie, a man... annihilates his dignity as a man.

Act only according to that maxim whereby you can at the same time will that it should become a universal law.