In science novelty emerges only with difficulty, manifested by resistance, against a background provided by expectation.

The decision to reject one paradigm is always simultaneously the decision to accept another, and the judgment leading to that decision involves the comparison of both paradigms with nature and with each other.

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.

Rather than being an interpreter, the scientist who embraces a new paradigm is like the man wearing inverting lenses.

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

Though the world does not change with a change of paradigm, the scientist afterward works in a different world... I am convinced that we must learn to make sense of statements that at least resemble these. What occurs during a scientific revolution is not fully reducible to a re-interpretation of individual and stable data. In the first place, the data are not unequivocally stable.

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.