Experiment Is The Sole Source Of Truth.

One Does Not Ask Whether A Scientific Theory Is True, But Only Whether It Is Convenient.

It Is Often Said That Experiments Should Be Made Without Preconceived Ideas. That Is Impossible. Not Only Would It Make Every Experiment Fruitless, But Even If We Wished To Do So, It Could Not Be Done. Every Man Has His Own Conception Of The World, And This He Cannot So Easily Lay Aside. We Must, Example, Use Language, And Our Language Is Necessarily Steeped In Preconceived Ideas. Only They Are Unconscious Preconceived Ideas, Which Are A Thousand Times The Most Dangerous Of All.

It May Happen That Small Differences In The Initial Conditions Produce Very Great Ones In The Final Phenomena.

I Entered An Omnibus To Go To Some Place Or Other. At That Moment When I Put My Foot On The Step The Idea Came To Me, Without Anything In My Former Thoughts Seeming To Have Paved The Way For It, That The Transformations I Had Used To Define The Fuchsian Functions Were Identical With Non-euclidean Geometry.

The Aim Of Science Is Not Things Themselves, As The Dogmatists In Their Simplicity Imagine, But The Relation Between Things.