Immanuel Kant

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.

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

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?

From such crooked wood as that which man is made of, nothing straight can be fashioned.

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.