Immanuel Kant

Even philosophers will praise war as ennobling mankind, forgetting the Greek who said: 'War is bad in that it begets more evil than it kills.'

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

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.

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.

Science is organized knowledge. Wisdom is organized life.

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

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

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

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?

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.

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

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

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