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

What chemists took from Dalton was not new experimental laws but a new way of practicing chemistry (he himself called it the 'new system of chemical philosophy'), and this proved so rapidly fruitful that only a few of the older chemists in France and Britain were able to resist it.

Every important idea in science sounds strange at first.

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

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.

Almost always the men who achieve these fundamental inventions of a new paradigm have been either very young or very new to the field whose paradigm they change.

The resolution of revolutions is selection by conflict within the scientific community of the fittest way to practice future science. The net result of a sequence of such revolutionary selections, separated by periods of normal research, is the wonderfully adapted set of instruments we call modern scientific knowledge.