Priestley [said] That Each Discovery We Make

With The Aid Of These Active Experimental Sciences Man Becomes An Inventor Of Phenomena, A Real Foreman Of Creation; And Under This Head We Cannot Set Limits To The Power That He May Gain Over Nature Through Future Progress Of The Experimental Sciences.

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.

Man Does Not Limit Himself To Seeing; He Thinks And Insists On Learning The Meaning Of Phenomena Whose Existence Has Been Revealed To Him By Observation. So He Reasons, Compares Facts, Puts Questions To Them, And By The Answers Which He Extracts, Tests One By Another. This Sort Of Control, By Means Of Reasoning And Facts, Is What Constitutes Experiment, Properly Speaking; And It Is The Only Process That We Have For Teaching Ourselves About The Nature Of Things Outside Us.

When We Meet A Fact Which Contradicts A Prevailing Theory, We Must Accept The Fact And Abandon The Theory, Even When The Theory Is Supported By Great Names And Generally Accepted.

Those Who Do Not Know The Torment Of The Unknown Cannot Have The Joy Of Discovery.