Philosophers of science have repeatedly demonstrated that more than one theoretical construction can always be placed upon a given collection of data.

Philosophers of science have repeatedly demonstrated that more than one theoretical construction can always be placed upon a given collection of data.

The man who is striving to solve a problem defined by existing knowledge and technique is not, however, just looking around. He knows what he wants to achieve, and he designs his instruments and directs his thoughts accordingly. Unanticipated novelty, the new discovery, can emerge only to the extent that his anticipations about nature and his instruments prove wrong... There is no other effective way in which discoveries might be generated.

Research under a paradigm must be a particularly effective way of inducing paradigm change.

Normal science does not aim at novelties of fact or theory and, when successful, finds none.

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.

Each paradigm will be shown to satisfy more or less the criteria that it dictates for itself and to fall short of a few of those dictated by its opponent.