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Normal Science – “The Structure of Scientific Revolutions” by Thomas Kuhn

Contributed by William Walter Kay BA JD © 2022

Thomas Kuhn’s The Structure of Scientific Revolutions debuted as a monograph in the 1962 edition of the International Encyclopedia of Unified Science. Later that year the University of Chicago issued Structure in book form. In 1962 Structure sold 919 copies. In 1963 it sold 774. A second edition, bolstered by a 30-page supplement, appeared in 1969. By 1971 some 90,000 hardcover and paperback copies had been sold. By 1987 over 650,000 copies had been sold as Structure had become required reading for many Sociology, Philosophy and History students. (1)

The current (2012) edition includes an Introduction by philosopher of science, Ian Hacking. Millions have read Structure. Kuhn hoped Structure would: “produce a decisive transformation in the image of science.” Mission accomplished, according to Professor Hacking.

Although it was destined to be overthrown by Bio-tech and Computer-tech, in 1962 Physics ruled the sciences. Forever the physicist, Kuhn took Physics as his model. While broadly chronicling ground-breaking scientific theories, Structure spares but half a page for Darwin.

A Math paper is like an egg – if it is part bad, it is all bad. (2) Humanities papers can be erroneous yet redeemable. Structure is a case in point. Structure:
a) is overwhelmingly about Physics which Kuhn wrongly presumes is indicative of all science;
b) uncritically relays dubious internal narratives about 20th century “revolutions” in Physics;
c) does not discuss the impact on science of social forces external to science;
d) neglects changes to higher education over the past four centuries; and,
e) ultimately defends the scientific status quo.
Nevertheless, what Structure says about “normal science” is more germane now than it was in 1962.


Kuhn defines normal science as:
…a strenuous and devoted attempt to force nature into the conceptual boxes supplied by a professional education.” (3)

To this he adds:

Mopping up operations are what engage most scientists throughout their careers. They constitute what I am calling normal science… No part of the aim of normal science is to call forth new sorts of phenomenon; indeed those that will not fit in the box are not seen at all. (4)


Normal science… suppresses fundamental novelties because they are necessarily subversive of its basic commitments. (5)


Aristotle’s “paradeigma” is synonymous with our “exemplar.” Paradeigmas were fitting scenarios; teaching aids. The Romans translated paradeigma into “exemplum.” Structure is saturated with the term “paradigm.” One scholar tabulated 22 distinct nuances of “paradigm” within Structure.

A paradigm is a set of analogies, equations, applications, experiments and observations related to a specific hypothesis. Paradigms form the foundations of scientific traditions. Paradigms are the “standard models” facilitating professional communication and assessment.

Paradigms are the “working hypotheses” unifying schools of thought. They are the foci of “scientific consensuses.”

Paradigms are inseparable from “scientific communities” i.e., thought-collectives that can number fewer than 100 scientists but which are frequently magnitudes larger. Scientific communities revolve around, and are defined by, their shared paradigms.

Successful paradigms spawn puzzles. Science education (which Kuhn casually calls “indoctrination”) consists mainly of making students solve the puzzles listed at the end of textbook chapters. These questions require students to demonstrate an ability to manipulate a paradigm’s core algebraic equations (, F=MA or E=MC2). Students are trained to spot signature paradigms inside a variety of phenomena.

Paradigms are the Alpha-to-Omega of normal science:

Without commitment to a paradigm there could be no normal science.” (6)

Normal science: “aims to refine, extend and articulate a paradigm that is already in existence.” (7)

Normal research discovers only what it is expected to discover. Normal scientists (in Kuhn’s words: “hacks”) grind away solely on officially pre-scripted conundrums because:
…in normal science, the research worker is a solver of puzzles, not a tester of paradigms. (8)

Thus, normal science journals contain only:
a) re-determinations of significant facts;
b) matchings of new facts to the paradigm; and,
c) further articulations of the paradigm, usually in algebraic treatises. (9)

Normal scientists stack stone upon stone in tribute to their almighty paradigm.


Kuhn dates the concept of “scientific revolution” to Kant’s Critique of Pure Reason (1787). Kant espied two scientific revolutions – the former occurring when Greeks transformed Babylonian mathematics into proofs from postulates; and the latter being Galileo’s use of the experimental method and the laboratory. Modern scholars identify the Scientific Revolution as an epic running from 1543 to 1687 starring Bacon, Galileo and Newton.

Kuhn penned The Copernican Revolution in 1957. Soon after, he toyed with an entirely separate revolution situated in the early 19th century wherein the study of heat, light, electricity and magnetism became mathematized. This period is better defined as a leap forward in measurement and instrumentation. Mathematization (i.e., algebraization) of these fields awaited Maxwell’s 1860s doodlings.

While normal science cannot change paradigms it can, according to Kuhn, generate anomalies that lead to crises which then cause paradigm shifts, i.e., scientific revolutions.

(This sequence of events preceded neither the Einsteinian nor the Quantum “revolutions” of early 20th century German Physics. Kuhn’s ulterior motive for writing Structure appears to have been to induct these two pseudo-revolutions into the hall of famous discoveries alongside Heliocentricity or the Oxygen Theory of Combustion et al. Kuhn’s exemplars don’t jibe with Kuhn’s paradigm.)

Pre-revolutionary periods (“crisis science”) witness proliferations of dueling articulations. Scientists talk past one another. Words change meanings. Limits to what proponents of opposing theories can communicate to one another are hit. “Incommensurability” reigns. A scientist’s rejection of one paradigm is simultaneously an embrace of its rival. Switches of allegiance are inspirational “conversions” not sober re-assessments.


Post-1962 the term “paradigm” became ubiquitous in academic literature. Kuhn sought to clarify paradigm’s meaning in a 1974 paper but eventually, having lost control of the word, abandoned it.

Kuhn became the darling of Science Studies scholars despite his disdain for Sociology. Various sociologies of science blossomed after Structure – nourished in part by the book’s success. Kuhn pooh-poohed this trend.


  1. Kuhn, Thomas. The Structure of Scientific Revolutions; University of Chicago, 2012. Data on book sales etc. found in this paragraph are from Ian Hacking’s 30-page Introduction. All further parenthetic references to Hacking are from this Introduction.
  2. Collins, Harry & Pinch, Trevor. The Golem: what you should know about science; University of Cambridge Press, Second Edition, 1998, page 154.
  3. Kuhn, page 5.
  4. Ibid, page 24.
  5. Ibid, page 5.
  6. Ibid, page 100.
  7. Ibid, page 122.
  8. Ibid, page 144.
  9. Ibid, page 24. See also Hacking’s Introduction in same volume.


Books by William Kay

From Malthus to Mifepristone: A Primer on the Population Control Movement

The Green Swastika: Environmentalism in the Third Reich


Post-Paris: Climate Talks and Geopolitics

1 Comment


    To borrow from the late Stephen Jay Gould, science proceeds by punctuated equilibrium. Consensus paradigms are necessary only to organise a hypothesis but as many have said, “If the facts change, I change my mind, What do you do?” How many facts will it take to convince the governments of the world that the UN IPCC paradigm is dangerous delusion.

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