Thomas Kuhn

"The successive transition from one paradigm to another via revolution is the usual developmental pattern of mature science."

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

"Discovery commences with the awareness of anomaly."

"The historian of science may be tempted to exclaim that when paradigms change, the world itself changes with them."

"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."