Our Ideas Are Only Intellectual Instruments Which

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

Real Science Exists, Then, Only From The Moment When A Phenomenon Is Accurately Defined As To Its Nature And Rigorously Determined In Relation To Its Material Conditions, That Is, When Its Law Is Known. Before That, We Have Only Groping And Empiricism.

Particular Facts Are Never Scientific; Only Generalization Can Establish Science.

It Is Impossible To Devise An Experiment Without A Preconceived Idea; Devising An Experiment, We Said, Is Putting A Question; We Never Conceive A Question Without An Idea Which Invites An Answer. I Consider It, Therefore, An Absolute Principle That Experiments Must Always Be Devised In View Of A Preconceived Idea, No Matter If The Idea Be Not Very Clear Nor Very Well Defined.

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.