There Are Two Things That

Thoughts Without Content Are Empty, Intuitions Without Concepts Are Blind.

Human Reason Has This Peculiar Fate That In One Species Of Its Knowledge It Is Burdened By Questions Which, As Prescribed By The Very Nature Of Reason Itself, It Is Not Able To Ignore, But Which, As Transcending All Its Powers, It Is Also Not Able To Answer.

Enlightenment Is Man's Leaving His Self-caused Immaturity. Immaturity Is The Incapacity To Use One's Intelligence Without The Guidance Of Another. Such Immaturity Is Self-caused If It Is Not Caused By Lack Of Intelligence, But By Lack Of Determination And Courage To Use One's Intelligence Without Being Guided By Another. Sapere Aude! Have The Courage To Use Your Own Intelligence! Is Therefore The Motto Of The Enlightenment.

Natural Science Physics Contains In Itself Synthetical Judgments A Priori, As Principles. ... Space Then Is A Necessary Representation A Priori, Which Serves For The Foundation Of All External Intuitions.

Physicians Think They Do A Lot For A Patient When They Give His Disease A Name.