Science Rejects The Indeterminate.

Our Ideas Are Only Intellectual Instruments Which We Use To Break Into Phenomena; We Must Change Them When They Have Served Their Purpose, As We Change A Blunt Lancet That We Have Used Long Enough.

We Must Alter Theory To Adapt It To Nature, But Not Nature To Adapt It To Theory.‎

We Must Remain, In A Word, In An Intellectual Disposition Which Seems Paradoxical, But Which, In My Opinion, Represents The True Mind Of The Investigator. We Must Have A Robust Faith And Yet Not Believe.

Men Who Believe Too Firmly In Their Theories, Do Not Believe Enough In The Theories Of Others. So ... These Despisers Of Their Fellows ... Make Experiments Only To Destroy A Theory, Instead Of To Seek The Truth.

Now, A Living Organism Is Nothing But A Wonderful Machine Endowed With The Most Marvellous Properties And Set Going By Means Of The Most Complex And Delicate Mechanism.