"normal Science" Means Research Firmly Based Upon

Literally As Well As Metaphorically, The Man Accustomed To Inverting Lenses Has Undergone A Revolutionary Transformation Of Vision.

As In Political Revolutions, So In Paradigm Choice--there Is No Standard Higher Than The Assent Of The Relevant Community. To Discover How Scientific Revolutions Are Effected, We Shall Therefore Have To Examine Not Only The Impact Of Nature And Of Logic, But Also The Techniques Of Persuasive Argumentation Effective Within The Quite Special Groups That Constitute The Community Of Scientists.

No Part Of The Aim Of Normal Science Is To Call Forth New Sorts Of Phenomena; Indeed Those That Will Not Fit The Box Are Often Not Seen At All. Nor Do Scientists Normally Aim To Invent New Theories, And They Are Often Intolerant Of Those Invented By Others.

Concerned To Reconstruct Past Ideas, Historians Must Approach The Generation That Held Them As The Anthropologist Approaches An Alien Culture. They Must, That Is, Be Prepared At The Start To Find That Natives Speak A Different Language And Map Experience Into Different Categories From Those They Themselves Bring From Home. And They Must Take As Their Object The Discovery Of Those Categories And The Assimilation Of The Corresponding Language.

The Historian Of Science May Be Tempted To Exclaim That When Paradigms Change, The World Itself Changes With Them.