Thomas Kuhn

“The proponents of competing paradigms practice their trades in different worlds.”

“Normal science, the activity in which most scientists inevitably spend almost all their time, is predicated on the assumption that the scientific community knows what the world is like.”

“The transfer of allegiance from paradigm to paradigm is a conversion experience that cannot be forced.”

“A paradigm is what the members of a scientific community, and they alone, share.”

“Successive paradigms tell us different things about the population of the universe and about that population’s behavior.”

“Anomaly appears only against the background provided by the paradigm.”

“The competition between paradigms is not the sort of battle that can be resolved by proofs.”

“The choice between competing paradigms is a choice between incompatible modes of community life.”

“What a man sees depends both upon what he looks at and also upon what his previous visual-conceptual experience has taught him to see.”

“The structure of a scientific revolution is that, for a time, normal science proceeds, until anomalies accumulate and a crisis occurs.”

“Under normal conditions the research scientist is not an innovator but a solver of puzzles...”

“History, if viewed as a repository for more than anecdote or chronology, could produce a decisive transformation in the image of science by which we are now possessed.”

“To be scientific is, among other things, to be objective and open-minded.”

“If I am right, then 'truth' may, like 'proof,' be a term with only intra-theoretic applications.”