Some Tactics in Galileo’s Propaganda for the Mathematization of Scientific Experience

  • Robert E. Butts
Part of the Boston Studies in the Philosophy of Science book series (BSPS, volume 155)


It has frequently been claimed that Galileo is the father of modern science. Historians of science who thus enshrine him claim for him not only important scientific discoveries, but also the discovery of the telescope, the introduction of the first genuine scientific method, defined mainly by reliance on experimentation, and the destruction of the prevailing Aristotelian metaphysics of his day. Other writers proclaim him for his restoration of Platonism (Koyré, 1939, 1943), or condemn him for introducing the basic elements of a subjectivist view of man destined to lead to no good (Burtt, 1932). In the past few years, we have begun to get new motivation to think about Galileo by new assessments of his work, some balanced (Shea, 1972), others highly skewed and controversial (Feyerabend, 1970b). Perhaps it is somewhere between the clear historico-philosophical analysis by Shea of Galileo’s achievements, and Feyerabend’s contention that Galileo was one of the greatest propagandists of ideas in the history of science that the truth about Galileo lies. Certainly enough is now know about this great man of science to realize that it would be a mistake to pin him up in a museum case as just one more ‘father.’


Physical Object Material Object Sensory Quality Secondary Quality Geometrical Theorem 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Like many people who write on Galileo I am not a Galileo specialist. I am aware that many of his contemporaries shared views similar to his on matters both philosophical and scientific. I am also aware—but in this paper will ignore—that a fairly substantial tradition of experimentation predated Galileo’s work. These historical concessions in no way militate against the interpretation of Galileo that I will offer.Google Scholar
  2. 2.
    Even if what follows confirms Feyerabend’s views of Galileo, there is no cause for alarm. What Galileo introduces on behalf of his programme for mathematizing scientific experience is only a sketch (negatively expressed-a caricature). Descartes, Newton and Leibniz do a better metaphysical job. Only Kant, however, sees the true limits of the philosophical task, and sets himself the required problems. There is philosophy as the introduction of bold, seemingly inappropriate ideas. There is philosophy as the analysis of the final success of such ideas. More than anything else it is the improbable link between Galileo and Kant that makes Galileo’s bravado both tolerable and interesting— at least to those of us who see his ideas as having some lasting effect upon modern philosophical norms. It is not of minor importance that Kant recognized this achievement of Galileo in his Preface to the second edition of Critique of Pure Reason. I will not in this note undertake to write the additional paper prerequisite to an understanding of Kant’s insight.Google Scholar
  3. 3.
    Galileo seems to have had something like this view of the two kinds of qualities in mind for a long time. He writes in ‘Letters on Sunspots...’, p. 124: “Hence I should infer that although it may be vain to seek to determine the true substance of the sunspots, still it does not follow that we cannot know some properties of them, such as their location, motion, shape, size, opacity, mutability, generation, and dissolution. These in turn may become the means by which we shall be able to philosophize better about other and more controversial qualities of natural substances. And finally by elevating us to the ultimate end of our labors, which is the love of the divine Artificer, this will keep us steadfast in the hope that we shall learn every other truth in Him, the source of all light and verity.” Galileo here writes partially in the Aristotelian idiom typical of his approach in the ‘Letter.’ But the fact is clear that he is already prepared to identify knowledge of some properties (geometrical and quantitative ones) with divine knowledge.Google Scholar
  4. 4.
    Compare Galileo’s form of the distinction with what Descartes has to say about the ball of wax in the second ‘Meditation.’ Inanities of standard history of philosophy aside, both Galileo and Descartes seem to have had something of great importance in mind when they introduced the distinction. But clearly neither of them thought of the distinction as underwriting a specific form of empiricism or rationalism (but then of course neither of them had read Hegel’s history of philosophy!). Drake’s note is in Drake, 1957, p. 274.Google Scholar
  5. 5.
    As we shall see there is a certain simplistic assumption underlying Galileo’s distinction, the assumption that sensory and what appear to be essentially private qualities cannot be made accessible to measurement. Half a programme is better than no programme at all. Nevertheless, there are many hints in his writings that Galileo at least entertained the notion of rendering secondary qualities fit for scientific measurement.Google Scholar
  6. 6.
    I have put this point somewhat unfairly and perhaps — so far as Galileo scholars are concerned — flippantly. But not much is at stake. Salviati had already argued that if a body is projected along a tangent struck anywhere on the surface of the earth it would not be released from the surface of the earth because of the acuteness of the angle involved. Shea, 1972, pp. 140-42, has shown that Salviati failed to take into account the centrifugal force of the moving earth. Given sufficient speed of centrifugal movement, the earth would throw off at least some bodies; and this is all that Simplicio needs for purposes of ridicule. Salviati’s real point comes next.Google Scholar
  7. 7.
    Chapter 4 of this book provides an elegant discussion of problems connected with conventionalism in geometry that in a sense ‘update’ Galileo’s implicit concerns in the Dialogue. Of equal importance is the general treatment of falsifiability in science in Chapter 17. Einstein’s fullest statement of his position on geometry is in Einstein, 1949, pp. 676-79.Google Scholar
  8. 8.
    I am here regarding the Duhem-Einstein thesis as a special case of the more general Duhem thesis. Roughly phrased, Duhem’s thesis points out that in the case of well articulated physical theories, negative experimental results cannot logically falsify the entire physical theory at issue, but only some (logically unspecifiable) aspect of that theory. This entails that the scientist has a choice — not to be made on empirical grounds — of which parts of the theory he will save. Galileo’s DMH is logically much stronger than the Duhem thesis: it asserts that no matter what a certain philosophical theory, complete with its ontology, will hold. The philosophical theory will of course be accepted for reasons far transcending the results of positive experimentation; indeed, the reasons will shape the very nature of experimentation.Google Scholar
  9. 9.
    Galileo’s The Assayer’ appeared in 1623, his Dialogue in 1632. In view of the fact that the Dialogue presents a massive frontal attack upon the stereotypical Aristotelian physics, including its reliance upon direct reports of perception, I think it is fair to assume that Galileo’s distinction in The Assayer’ is presupposed in the later work. See note 3 above for suggestions of Galileo’s early indications of acceptance of the distinction.Google Scholar
  10. 10.
    Shea, 1972, pp. 159-63, contains an excellent brief discussion of Galileo’s free fall law. My own account owes much to Shea’s treatment of the topic.Google Scholar
  11. 11.
    Shea, 1972, pp. 39-40, provides an insightful discussion of Galileo’s use of experiments as regulative principles. He writes: “It would seem, therefore, that experiments are not essential for Galileo in the sense that their mere mechanical repetition can produce a theory. Rather they are important inasmuch as they play a discriminatory role in the selection of the set of principles that will be used as the basis of a physical interpretation of nature. This means that framing exact hypotheses is only the first step in science. The second one is deriving practical conclusions from them and devising well-chosen experiments to test them. It is one of Galileo’s great contributions to the development of scientific method that he clearly recognised the necessity of isolating the true cause by creating artificial conditions where one element is varied at a time.”.Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 1993

Authors and Affiliations

  • Robert E. Butts
    • 1
  1. 1.Department of PhilosophyThe University of Western OntarioCanada

Personalised recommendations