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Why Astrology is a Pseudoscience

Published online by Cambridge University Press:  28 February 2022

Paul R. Thagard*
University of Michigan-Dearborn


Most philosophers and historians of science agree that astrology is a pseudoscience, but there is little agreement on why it is a pseudoscience. Answers range from matters of verifiability and falsifiability, to questions of progress and Kuhnian normal science, to the different sorts of objections raised by a large panel of scientists recently organized by The Humanist magazine. Of course there are also Feyerabendian anarchists and others who say that no demarcation of science from pseudoscience is possible. However, I shall propose a complex criterion for distinguishing disciplines as pseudoscientific; this criterion is unlike verificationist and falsificationist attempts in that it introduces social and historical features as well as logical ones.

I begin with a brief description of astrology. It would be most unfair to evaluate astrology by reference to the daily horoscopes found in newspapers and popular magazines.

Part VI. Aspects of Rationality
Copyright © 1978 by the Philosophy of Science Association

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I am grateful to Dan Hausman and Elias Baumgarten for comments.


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