There Is Nothing Higher Than Reason.

Philosophical Knowledge Is The Knowledge Gained By Reason From Concepts ; Mathematical Knowledge Is The Knowledge Gained By Reason From The Construction Of Concepts.

Man's Duty Is To Improve Himself; To Cultivate His Mind; And, When He Finds Himself Going Astray, To Bring The Moral Law To Bear Upon Himself.

Thoughts Without Content Are Empty, Intuitions Without Concepts Are Blind... The Understanding Can Intuit Nothing, The Senses Can Think Nothing. Only Through Their Union Can Knowledge Arise.

I Ought Never To Act Except In Such A Way That I Could Also Will That My Maxim Should Become A Universal Law.

It Is Not Necessary That Whilst I Live I Live Happily; But It Is Necessary That So Long As I Live I Should Live Honourably.