Thoughts without content are empty, intuitions without concepts are blind.
To be is to do.
Out of timber so crooked as that from which man is made nothing entirely straight can be carved.
All the interests of my reason, speculative as well as practical, combine in the three following questions: 1. What can I know? 2. What ought I to do? 3. What may I hope?
Religion is the recognition of all our duties as divine commands.
If man makes himself a worm he must not complain when he is trodden on.
Intuition and concepts constitute... the elements of all our knowledge, so that neither concepts without an intuition in some way corresponding to them, nor intuition without concepts, can yield knowledge.
From such crooked wood as that which man is made of, nothing straight can be fashioned.
He who is cruel to animals becomes hard also in his dealings with men. We can judge the heart of a man by his treatment of animals.
Metaphysics is a dark ocean without shores or lighthouse, strewn with many a philosophic wreck.
By a lie, a man... annihilates his dignity as a man.
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.
Morality is not the doctrine of how we may make ourselves happy, but how we may make ourselves worthy of happiness.
Always recognize that human individuals are ends, and do not use them as means to your end.
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.
Immaturity is the incapacity to use one's intelligence without the guidance of another.
It is not necessary that whilst I live I live happily; but it is necessary that so long as I live I should live honourably.
Happiness is not an ideal of reason, but of imagination.
Ingratitude is the essence of vileness.
Seek not the favor of the multitude; it is seldom got by honest and lawful means. But seek the testimony of few; and number not voices, but weigh them.