PSA 1974 pp 79-104 | Cite as

Galileo and Reasoning ex Suppositione: the Methodology of the two New Sciences

  • William A. Wallace
Part of the Boston Studies in the Philosophy of Science book series (BSPS, volume 32)


Galileo has been seen, from the philosophical point of view, alternately as a Platonist whose rationalist insights enabled him to read the book of nature because it was written in ‘the language of mathematics,’ and as an experimentalist who used the hypothetico-deductive methods of modern science to establish his new results empirically (McTighe, 1967; Settle, 1967; Drake, 1970; Shapere, 1974). Both of these views present difficulties. In this paper I shall make use of recent historical research to argue that neither is correct, that the method utilized by Galileo was neither Platonist nor hypothetico-deductivist, but was basically Aristotelian and Archimedean in character. This method, moreover, was not merely that of classical antiquity, but it had been emended and rejuvenated in the sixteenth century, and then not by Greek humanist Aristotelians or by Latin Averroists but rather by scholastic authors of the Collegio Romano whose own inspiration derived mainly from Thomas Aquinas. Other influences, of course, were present, and these came from other medieval and Renaissance writers, but these need not concern us in what follows.


Middle Period Heavy Body Lunar Eclipse Hypothetical Reasoning Movable Object 
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Copyright information

© D. Reidel Publishing Company, Dordrecht, Holland 1976

Authors and Affiliations

  • William A. Wallace
    • 1
  1. 1.The Catholic University of AmericaUSA

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