---
title: "Demarcation problem"
chunk: 2/3
source: "https://en.wikipedia.org/wiki/Demarcation_problem"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:36:27.454881+00:00"
instance: "kb-cron"
---

== Kuhnian postpositivism ==
Thomas Kuhn, an American historian and philosopher of science, is often associated with what has been termed postpositivism or postempiricism. In his 1962 book The Structure of Scientific Revolutions, Kuhn divided the process of doing science into two different endeavors, which he termed normal science and extraordinary science (sometimes known as "revolutionary science"), the latter of which introduces a new "paradigm" that solves new problems while continuing to provide solutions to the problems solved by the preceding paradigm.

Finally, and this is for now my main point, a careful look at the scientific enterprise suggests that it is normal science, in which Sir Karl's sort of testing does not occur, rather than extraordinary science which most nearly distinguishes science from other enterprises. If a demarcation criterion exists (we must not, I think, seek a sharp or decisive one), it may lie just in that part of science which Sir Karl ignores.
Kuhn's view of demarcation is most clearly expressed in his comparison of astronomy with astrology. Since antiquity, astronomy has been a puzzle-solving activity and therefore a science. If an astronomer's prediction failed, then this was a puzzle that he could hope to solve for instance with more measurements or with adjustments of the theory. In contrast, the astrologer had no such puzzles since in that discipline "particular failures did not give rise to research puzzles, for no man, however skilled, could make use of them in a constructive attempt to revise the astrological tradition" ... Therefore, according to Kuhn, astrology has never been a science.
Popper criticized Kuhn's demarcation criterion, saying that astrologers are engaged in puzzle solving, and that therefore Kuhn's criterion recognized astrology as a science. He stated that Kuhn's criterion results in a "major disaster ... [the] replacement of a rational criterion of science by a sociological one".

== Feyerabend and Lakatos ==
Kuhn's work largely called into question Popper's demarcation, and emphasized the human, subjective quality of scientific change. Paul Feyerabend was concerned that the very question of demarcation was insidious: science itself had no need of a demarcation criterion, but instead some philosophers were seeking to justify a special position of authority from which science could dominate public discourse. Feyerabend argued that science is not in fact special in terms of either its logic or method, and no claim to special authority made by scientists can be sustained. He argued that, within the history of scientific practice, no rule or method can be found that has not been violated or circumvented at some point in order to advance scientific knowledge. Both Imre Lakatos and Feyerabend suggest that science is not an autonomous form of reasoning, but is inseparable from the larger body of human thought and inquiry.

== Thagard ==
Paul R. Thagard proposed another set of principles to try to overcome these difficulties, and argued that it is important for society to find a way of doing so. According to Thagard's method, a theory is not scientific if it satisfies two conditions:

The theory has been less progressive than alternative theories over a long period of time, and has many unsolved problems; and...
The community of practitioners makes little attempt to develop the theory towards solutions of the problems, shows no concern for attempts to evaluate the theory in relation to others, and is selective in considering confirmations and disconfirmations.
Thagard specified that sometimes theories will spend some time as merely "unpromising" before they truly deserve the title of pseudoscience. He cited astrology as an example: it was stagnant compared to advances in physics during the 17th century, and only later became "pseudoscience" in the advent of alternative explanations provided by psychology during the 19th century.
Thagard also stated that his criteria should not be interpreted so narrowly as to allow willful ignorance of alternative explanations, or so broadly as to discount our modern science compared to science of the future. His definition is a practical one, which generally seeks to distinguish pseudoscience as areas of inquiry which are stagnant and without active scientific investigation.

== Some historians' perspectives ==
Many historians of science are concerned with the development of science from its primitive origins; consequently they define science in sufficiently broad terms to include early forms of natural knowledge. In the article on science in the eleventh edition of the Encyclopædia Britannica, the scientist and historian William Cecil Dampier Whetham defined science as "ordered knowledge of natural phenomena and of the relations between them". In his study of Greek science, Marshall Clagett defined science as "first, the orderly and systematic comprehension, description and/or explanation of natural phenomena and, secondly, the [mathematical and logical] tools necessary for the undertaking". A similar definition appeared more recently in David Pingree's study of early science: "Science is a systematic explanation of perceived or imaginary phenomena, or else is based on such an explanation. Mathematics finds a place in science only as one of the symbolical languages in which scientific explanations may be expressed." These definitions tend to emphasize the subject matter of science rather than its method and from these perspectives, the philosophical concern to establish a demarcation between science and non-science becomes "problematic, if not futile".