Science Is Practical Philosophy.

For I Found Myself Embarrassed With So Many Doubts And Errors That It Seemed To Me That The Effort To Instruct Myself Had No Effect Other Than Th Eincreasing Discovery Of My Own Ignorance

It Is Not Enough To Have A Good Mind. The Main Thing Is To Use It Well.

But I Cannot Forget That, At Other Times I Have Been Deceived In Sleep By Similar Illusions; And, Attentively Considering Those Cases, I Perceive So Clearly That There Exist No Certain Marks By Which The State Of Waking Can Ever Be Distinguished From Sleep, That I Feel Greatly Astonished; And In Amazement I Almost Persuade Myself That I Am Now Dreaming.

The Two Operations Of Our Understanding, Intuition And Deduction, On Which Alone We Have Said We Must Rely In The Acquisition Of Knowledge.

The Only Thing That I Know, Is That I Know Nothing