It Is By Logic We Prove. It

It May Happen That Small Differences In The Initial Conditions Produce Very Great Ones In The Final Phenomena. A Small Error In The Former Will Produce An Enormous Error In The Later. Prediction Becomes Impossible, And We Have The Fortuitous Phenomena.

The Advance Of Science Is Not Comparable To The Changes Of A City, Where Old Edifices Are Pitilessly Torn Down To Give Place To New, But To The Continuous Evolution Of Zoologic Types Which Develop Ceaselessly And End By Becoming Unrecognisable To The Common Sight, But Where An Expert Eye Finds Always Traces Of The Prior Work Of The Centuries Past. One Must Not Think Then That The Old-fashioned Theories Have Been Sterile And Vain.

It Is A Misfortune For A Science To Be Born Too Late When The Means Of Observation Have Become Too Perfect. That Is What Is Happening At This Moment With Respect To Physical Chemistry; The Founders Are Hampered In Their General Grasp By Third And Fourth Decimal Places.

Every Good Mathematician Should Also Be A Good Chess Player And Vice Versa.

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