Thomas Kuhn Quotes

All significant breakthroughs are break -“withs” old ways of thinking.

The answers you get depend upon the questions you ask.

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.

We see the world in terms of our theories.

Individuals who break through by inventing a new paradigm are almost always either very young men or very new to the field whose paradigm they change. These are the men who, being little committed by prior practice to the traditional rules of normal science, are particularly likely to see that those rules no longer define a playable game and conceive another set that can replace them.

Every important idea in science sounds strange at first.

Far from being magisterial in its objectivity, science was conditioned by history, society, and the prejudices of scientists.

The transition between competing paradigms cannot be made a step at a time, forced by logic and neutral experience. Like the gestalt switch, it must occur all at once (though not necessarily in an instant) or not at all.

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

Normal science, the activity in which most scientists inevitably spend most all their time, is predicated on the assumption that the scientific community knows what the world is like. Normal science often suppresses fundamental novelties because they are necessarily subversive of its basic commitments.

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

Probably, the single most prevalent claim advanced by the proponents of a new paradigm is that they can solve the problems that led the old one to a crisis.

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.

The historian of science may be tempted to claim that when paradigms change, the world itself changes with them. Led by a new paradigm, scientists adopt new instruments and look in new places. even more important, during revolutions, scientists see new and different things when looking with familiar instruments in places they have looked before. It is rather as if the professional community had been suddenly transported to another planet where familiar objects are seen in a different light and are joined by unfamiliar ones as well.

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.

Under normal conditions the research scientist is not an innovator but a solver of puzzles, and the puzzles upon which he concentrates are just those which he believes can be both stated and solved within the existing scientific tradition.

Communication across the revolutionary divide is inevitably partial.

The crises of our time, it becomes increasingly clear, are the necessary impetus for the revolution now under way. And once we understand nature's transformative powers, we see that it is our powerful ally, not a force to feared our subdued.

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

All crises begin with the blurring of a paradigm and the consequent loosening of the rules for normal research. .. Or finally, the case that will most concern us here, a crisis may end with the emergence of a new candidate for paradigm and with the ensuing battle over its acceptance.

No part of the aim of normal science is to call forth new sorts of phenomena; indeed those that will not fit the box are often not seen at all. Nor do scientists normally aim to invent new theories, and they are often intolerant of those invented by others.

Political revolutions aim to change political institutions in ways that those institutions themselves prohibit. Their success therefore necessitates the partial relinquishment of one set of institutions in favor of another, and in the interim, society is not fully governed by institutions at all

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

Literally as well as metaphorically, the man accustomed to inverting lenses has undergone a revolutionary transformation of vision.

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.