Always treat people as ends in themselves, never as means to an end.

[S]uppose the mind of [a] friend of humanity were clouded over with his own grief, extinguishing all sympathetic participation in the fate of others; he still has the resources to be beneficent to those suffering distress, but the distress of others does not touch him because he is sufficiently busy with his own; and now, where no inclination any longer stimulates him to it, he tears himself out of his deadly insensibility and does the action without any inclination, solely from duty.

Human reason is by nature architectonic.

We can never, even by the strictest examination, get completely behind the secret springs of action.

All thought must, directly or indirectly, by way of certain characters, relate ultimately to intuitions, and therefore, with us, to sensibility, because in no other way can an object be given to us.

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.

In law a man is guilty when he violates the rights of others. In ethics he is guilty if he only thinks of doing so.