“...new prejudices will serve as well as old ones to harness the great unthinking masses.For this enlightenment, however, nothing is required but freedom, and indeed the most harmless among all the things to which this term can properly be applied. It is the freedom to make public use of one's reason at every point. But I hear on all sides, 'Do not argue!' The Officer says: 'Do not argue but drill!' The tax collector: 'Do not argue but pay!' The cleric: 'Do not argue but believe!' Only one prince in the world says, 'Argue as much as you will, and about what you will, but obey!' Everywhere there is restriction on freedom.”

“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.”

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

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

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

“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.”

“To be is to do.”

“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.'”