Thomas Kuhn

"Anomalies have always been recognized since earliest antiquity."

"Knowledge and authority become obstacles to knowledge when they prevent us from questioning established paradigms."

"The study of paradigms is what mainly prepares the student for membership in the particular scientific community."

"We learn to see the world differently when our paradigm shifts."

"Scientific progress is not evolutionary, it is revolutionary in nature."

"The transition from one paradigm to another cannot be made a step at a time."

"Before the Scientific Revolution, the natural world was seen through theological lenses almost entirely."

"What we see depends on what we're looking for, and what we're looking for depends on our paradigm."

"The older a science, the more abstract its laws and the more formal its expression become."

"Scientists will accept a new paradigm only after it has solved the problems that created the crisis."

"Incompleteness as a feature of scientific theories is not a defect but a necessity."

"A scientist who experiences an anomaly in his work is already in crisis."

"The Ptolemaic tradition and the Copernican system are incommensurable."

"What is revolutionary is not always what is true."

"The historian's task is not to defend paradigms but to understand how they have functioned."

"Every civilization has seen the universe differently, and most have resolved its conflicts into different paradigms."

"Scientific communities are coherent partly because of shared values, which both permit and require a discipline."

"Each paradigm brings new puzzles and new rules for solving them."

"The impossibility of proving that one paradigm is superior may seem a flaw."

"Science progresses through revolutions, not through accumulation."

"In science, there is no permanent, unchangeable bedrock."

"The textbooks describe the established knowledge, not the processes of discovery."

"A new paradigm often seems less elegant than the old, at least at first."

"The world of the scientist is not the same as the world of the ordinary man."

"Paradigm shifts are not corrections of errors but shifts in perspective."

"We do not see the world as it is, we see it as we are."

"The acceptance of a new paradigm is always an act of faith."

"Scientists are trained to see a certain way, to interpret a certain way, to measure a certain way."

"The scientist is not free to choose which paradigm he will follow without good reason."

"Normal science is cumulative, but revolutions are not."