To be is to do.

It is beyond a doubt that all our knowledge begins with experience.

Experience without theory is blind, but theory without experience is mere intellectual play.

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

Happiness is not an ideal of reason, but of imagination.

Morality is not the doctrine of how we may make ourselves happy, but how we may make ourselves worthy of happiness.

It is not God's will merely that we should be happy, but that we should make ourselves happy.

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

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

I had therefore to remove knowledge, in order to make room for belief.

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.

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.

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

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?