Immanuel Kant

German philosopher and one of the central Enlightenment thinkers

All our knowledge begins with the senses, proceeds then to the understanding, and ends with reason. There is nothing higher than reason.
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.
It is beyond a doubt that all our knowledge begins with experience.
To be is to do.
Morality is not the doctrine of how we may make ourselves happy, but how we may make ourselves worthy of happiness.
What can I know? What ought I to do? What can I hope?
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.
Two things awe me most, the starry sky above me and the moral law within me.
Act that your principle of action might safely be made a law for the whole world.