Duty is the necessity to act out of reverence for the law.
Upon the solution of this problem, or upon sufficient proof of the impossibility of synthetical knowledge a priori, depends the existence or downfall of metaphysics.
Time is not an empirical concept. For neither co-existence nor succession would be perceived by us, if the representation of time did not exist as a foundation a priori.
Freedom is that faculty that enlarges the usefulness of all other faculties.
The hand is the visible part of the brain.
We ourselves introduce that order and regularity in the appearance which we entitle “nature”. We could never find them in appearances had we not ourselves, by the nature of our own mind, originally set them there.
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.
Humanity is at its greatest perfection in the race of the whites.
Imagination is a powerful agent for creating, as it were, a second nature out of the material supplied to it by actual nature.
When I could have used a wife, I could not support one; and when I could support one, I no longer needed any.
Man must be disciplined, for he is by nature raw and wild.
The enjoyment of power inevitably corrupts the judgment of reason, and perverts its liberty.
God, freedom, and immortality are untenable in the light of pure reason.
Standing armies shall in time be totally abolished.
The bad thing of war is, that it makes more evil people than it can take away.
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.
Man desired concord; but nature knows better what is good for his species; she desires discord. Man wants to live easy and content; but nature compels him to leave ease... and throw himself into roils and labors.
The function of the true state is to impose the minimum restrictions and safeguard the maximum liberties of the people, and it never regards the person as a thing.
What are the aims which are at the same time duties? They are perfecting of ourselves, the happiness of others.
Suicide is not abominable because God prohibits it; God prohibits it because it is abominable.