May you live your life as if the maxim of your actions were to become universal law.

Thoughts without content are empty, intuitions without concepts are blind.

Out of timber so crooked as that from which man is made nothing entirely straight can be carved.

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.

But although all our knowledge begins with experience, it does not follow that it arises from experience.

Metaphysics is a dark ocean without shores or lighthouse, strewn with many a philosophic wreck.

Nothing is divine but what is agreeable to reason.

What can I know? What ought I to do? What can I hope?

Religion is the recognition of all our duties as divine commands.

So act that your principle of action might safely be made a law for the whole world.

The only objects of practical reason are therefore those of good and evil. For by the former is meant an object necessarily desired according to a principle of reason; by the latter one necessarily shunned, also according to a principle of reason.

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.

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.

Two things awe me most, the starry sky above me and the moral law within me.

Immaturity is the incapacity to use one's intelligence without the guidance of another.

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

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.

All our knowledge begins with the senses, proceeds then to the understanding, and ends with reason. There is nothing higher than reason.

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.