# Normal science

Normal science, identified and elaborated on by Thomas Samuel Kuhn in The Structure of Scientific Revolutions, is the regular work of scientists theorizing, observing, and experimenting within a settled paradigm or explanatory framework. Kuhn explained normal science as slowly accumulating detail in accord with established broad theory, without questioning or challenging the underlying assumptions of that theory.

## Quotes

* Kuhn used the phrase “normal science” for scientific work that occurs within the framework provided by a paradigm. A key feature of normal science is that it is well organized. Scientists doing normal science tend to agree on which problems are important, on how to approach these problems, and on how to assess possible solutions. … He argued that it is false that science exhibits a permanent openness to the testing of fundamental ideas. Not only that, but science would be worse off if it had the kind of openness that philosophers have treasured. … For Kuhn, there are two distinct kinds of scientific change: change within normal science, and revolutionary science. (These are bridged by “crisis science,” a period of unstable stasis.) These two kinds of change have very different epistemological features; when we try to apply concepts such as justification, rationality, and progress to science, according to Kuhn we find that normal and revolutionary science have to be described very differently. Within normal science, there are clear and agreed-upon standards for the justification of arguments; within revolutionary science there are not. Within normal science there is clear progress; within revolutionary science it is very hard to tell (and it is hard to even interpret the question).
** Peter Godfrey-Smith, Theory and Reality: An Introduction to the Philosophy of Science (2003), Chap. 5 : Kuhn and Normal Science
* Normal science is work aimed at extending and refining the paradigm. A good normal scientist is committed to the paradigm and does not question it. Normal scientists extend their paradigm both theoretically and experimentally. Anomalies inevitably arise, however, and eventually these reach a kind of critical mass, at which point scientists lose faith in the paradigm and the field plunges into a state of crisis. … One problem comes from Kuhn’s insistence that, except in unusual cases, a scientific field has one paradigm per field per time. … Secondly, Kuhn exaggerates the degree of commitment that a normal scientist does and should have to a paradigm. Kuhn describes the attitude of a normal scientist in very strong terms. Scientific education is a kind of “indoctrination,” which results in scientists having a deep “faith” in their paradigm. As a description of how science actually works, this seems exaggerated. Sometimes there is a faithlike commitment, but sometimes there is not. Many scientists are able to say that they always work within a paradigm, for practical reasons, while being very aware of the possibility of error and the eventual replacement of their framework. One of the ironies of Kuhn’s influence is that his book might have weakened the faith of some normal scientists, even though Kuhn thought that normal scientists should have a deep faith in their paradigms!
** Peter Godfrey-Smith, Theory and Reality: An Introduction to the Philosophy of Science (2003), Chap. 5 : Kuhn and Normal Science
* For a current illustration of what is absolutely right, and also of what is questionable, in Kuhn’s idea of normal science, notice that the high-energy physics most widely reported by science journalists is the search for the Higgs particle. This involves an incredible treasury of both money and talent, all of which is dedicated to confirming what present physics teaches—that there is an as yet undetected particle that plays an essential role in the very existence of matter. Innumerable puzzles, ranging from mathematics to engineering, must be solved en route. In one sense, nothing new in the way of theory or even phenomena is anticipated. That’s what Kuhn was right about. Normal science does not aim at novelty. But novelty can emerge from confirmation of theories already held. Indeed it is hoped that when the right conditions for eliciting the particle are finally established, an entire new generation of high-energy physics will begin. The characterization of normal science as puzzle-solving suggests that Kuhn did not think normal science was important. On the contrary, he thought scientific activity was enormously important and that most of it is normal science. Nowadays even scientists skeptical of Kuhn’s thought about revolutions have great respect for his account of normal science.
** Ian Hacking (2012), Introductory Essay, in 50th anniversary edition of Thomas Kuhn's The Structure of Scientific Revolution
* In my view the ‘normal’ scientist, as Kuhn describes him, is a person one ought to be sorry for. (According to Kuhn’s views about the history of science, many great scientists must have been ‘normal’; yet since I do not feel sorry for them, I do not think that Kuhn’s views can be quite right.) The ‘normal’ scientist, in my view, has been taught badly. I believe, and so do many others, that all teaching on the University level (and if possible below) should be training and encouragement in critical thinking. The ‘normal’ scientist, as described by Kuhn, has been badly taught. He has been taught in a dogmatic spirit: he is a victim of indoctrination. He has learned a technique which can be applied without asking for the reason why (especially in quantum mechanics). As a consequence, he has become what may be called an applied scientist, in contradistinction to what I should call a pure scientist.
** Karl Popper, "Normal Science and Its Dangers", in Imre Lakatos & Alan Musgrave (eds.), Criticism and the Growth of Knowledge (1970)
* It was not Kuhn's description of scientific revolutions that impressed me so much when I first read Structure in 1972, but rather his treatment of normal science. Kuhn showed that a period of normal science is not a time of stagnation, but an essential phase of scientific progress. This had become important to me personally in the early 1970s because of recent developments in both cosmology and elementary particle physics.
** Steven Weinberg, "The Revolution That Didn't Happen", The New York Review of Books (October 8, 1998)

## See also

* Thomas Kuhn
* Paradigm shift