The First Requirement In Using Statistics Is

Progress Is Achieved By Exchanging Our Theories For New Ones Which Go Further Than The Old, Until We Find One Based On A Larger Number Of Facts. ... Theories Are Only Hypotheses, Verified By More Or Less Numerous Facts. Those Verified By The Most Facts Are The Best, But Even Then They Are Never Final, Never To Be Absolutely Believed.

Put Off Your Imagination, As You Put Off Your Overcoat, When You Enter The Laboratory. Put It On Again, As You Put On Your Overcoat, When You Leave.

Mediocre Men Often Have The Most Acquired Knowledge. It Is In The Darker. It Is In The Darker Regions Of Science That Great Men Are Recognized; They Are Marked By Ideas Which Light Up Phenomena Hitherto Obscure And Carry Science Forward.

A Contemporary Poet Has Characterized This Sense Of The Personality Of Art And Of The Impersonality Of Science In These Words,-'art Is Myself; Science Is Ourselves. '

The Physiologist Is Not A Man Of The World, He Is A Scientist, A Man Caught And Absorbed By A Scientific Idea That He Pursues; He No Longer Hears The Cries Of The Animals, No Longer Sees The Flowing Blood, He Sees Only His Idea: Organisms That Hide From Him Problems That He Wants To Discover. He Doesn't Feel That He Is In A Horrible Carnage; Under The Influence Of A Scientific Idea, He Pursues With Delight A Nervous Filament Inside Stinking And Livid Flesh That For Any Other Person Would Be An Object Of Disgust And Horror.