The ongoing epistemological debate on scientific thought experiments (TEs) revolves, in part, around the now famous Galileo’s falling bodies TE and how it could justify its conclusions. In this paper, I argue that the TE’s function is misrepresented in this a-historical debate. I retrace the history of this TE and show that it constituted the first step in two general “argumentative strategies”, excogitated by Galileo to defend two different theories of free-fall, in 1590’s and then in the 1638. (...) I analyse both argumentative strategies and argue that their function was to eliminate potential causal factors: the TE serving to eliminate absolute weight as a causal factor, while the subsequent arguments served to explore the effect of specific weight, with conflicting conclusions in 1590 and 1638. I will argue thorough the paper that the TE is best grasped when we analyse Galileo’s restriction, in the TE’s scenario and conclusion, to bodies of the same material or specific weight. Finally, I will draw out two implications for the debate on TEs. (shrink)

The first attempted derivation by Galileo of the law relating space and time in free fall that has survived is preserved on an otherwise unidentified sheet bound among his manuscripts preserved at Florence. It is undoubtedly closely associated with a letter from Galileo to Paolo Sarpi, dated 16 October 1604, which somehow found its way into the Seminary of Pisa, where it is still preserved. Those two documents, together with the letter from Sarpi to Galileo which seems to have inspired (...) them, are translated in full below. Sarpi's letter, dated 9 October 1604, suggests that recent oral discussions of problems of motion had recently taken place between the two men. It reads as follows:“In sending you the enclosure, it occurs to me to propose to you a problem to resolve, and another that seems to me paradoxical. (shrink)

The most perplexing aspect of Galileo's work in physics is without doubt the sharp distinction one can draw between his essentially dynamic studies in such juvenilia as De Motu and the consciously kinematical approach of his later output—particularly the Two New Sciences. Whether one chooses to call this a shift from the “why” of motion to the “how”, or, as I should prefer, a shift from dynamics to kinematics, there can be no denying its existence. The Galileo who wrote (...) that “The present does not seem to be the proper time to investigate the cause of the acceleration of natural motion …” is, on the face of it, a very different man from the one who had earlier written almost an entire treatise on precisely this topic. (shrink)

Galileo's refutation of the speed-distance law of fall in his Two New Sciences is routinely dismissed as a moment of confused argumentation. We urge that Galileo's argument correctly identified why the speed-distance law is untenable, failing only in its very last step. Using an ingenious combination of scaling and self-similarity arguments, Galileo found correctly that bodies, falling from rest according to this law, fall all distances in equal times. What he failed to recognize in the last (...) step is that this time is infinite, the result of an exponential dependence of distance on time. Instead, Galileo conflated it with the other motion that satisfies this ‘equal time’ property, instantaneous motion. (shrink)

According to Aristotelian physics, there was a fundamental distinction between natural and violent motion. When the cause of the motion was internal to the moving body, that motion was regarded as natural. Violent motion was supposed to have an external efficient cause. It should stop as soon as this external cause ceased its action. The fall of a body was believed to have an internal cause – the very nature of the heavy body – but the motion of a projectile (...) was supposed to be accidental and a violent one, produced by an external agent and maintained by the continuous action of the air around it. Those distinctions disappeared from physics during the 17th century. Descartes and Newton do not address those problems. However, in Galileo’s thought those distinctions were still present, and they did play a relevant role in his physics. Some central arguments presented by Galileo Galilei in the Dialogues concerning the two chief world systems depended on the characterisation of circular motion as “natural”. Considerations concerning natural or violent motion, circular and straight motions, provided a trap that led Galileo astray to ideas that seem extremely odd, from the point of view of classical mechanics. This article shows how Galileo struggled with those Aristotelian concepts when he tried to understand the nature of the motion of falling bodies. (shrink)

This essay attempts to demonstrate that it is doubtful if Galileo's famous thought experiment concerning falling bodies in his 'Dialogues Concerning Two New Sciences' (Galileo 1954: 61-64) actually does succeed in proving that Aristotle was wrong in claiming that "bodies of different weight […] move […] with different speeds which stand to one another in the same ratio as their weights," (Galileo 1954: 61). (Part I); and further that it is likewise doubtful that that argument does (...) or even can establish Galileo's own famous 'Law of Falling Bodies,' viz., that regardless of their weight all bodies fall with the same speed. (Part II). (shrink)

This paper aims to formalize Galileo’s argument against the Aristotelian view that the weight of free-falling bodies influences their speed. I obtain this via the application of concepts of parthood and of mereological sum, and via recognition of a principle which is not explicitly formulated by the Italian thinker but seems to be natural and helpful in understanding the logical mechanism behind Galileo’s train of thought. I also compare my reconstruction to one of those put forward by Atkinson (...) and Peijnenburg :115–136, 2004), and propose a formalization which is based on a principle introduced by them, which I shall call the speed is mediative principle. (shrink)

This essay attempts to demonstrate that it is doubtful if Galileo's famous thought experiment concerning falling bodies in his 'Dialogues Concerning Two New Sciences' (Galileo 1954: 61-64) actually does succeed in proving that Aristotle was wrong in claiming that "bodies of different weight […] move […] with different speeds which stand to one another in the same ratio as their weights," (Galileo 1954: 61). (Part I); and further that it is likewise doubtful that that argument does (...) or even can establish Galileo's own famous 'Law of Falling Bodies,' viz., that regardless of their weight all bodies fall with the same speed. (Part II). (shrink)

This article analyzes the evolution of Mersenne's views concerning the validity of Galileo's theory of acceleration. After publishing, in 1634, a treatise designed to present empirical evidence in favor of Galileo's odd-number law, Mersenne developed over the years the feeling that only the elaboration of a physical proof could provide sufficient confirmation of its validity. In the present article, I try to show that at the center of Mersenne's worries stood Galileo's assumption that a falling body (...) had to pass in its acceleration through infinite degrees of speed. His extensive discussions with, or his reading of, Descartes, Gassendi, Baliani, Fabri, Cazre, Deschamps, Le Tenneur, Huygens, and Torricelli led Mersenne to believe that the hypothesis of a passage through infinite degrees of speed was incompatible with any mechanistic explanation of free fall. (shrink)

Thought experiments provide a conspicuous case study for epistemologists of the imagination. Galileo’s famous thought experiment about falling stones is a central example in the debate about how thought experiments in science work. According to a standard interpretation, the thought experiment poses a challenge to an Aristotelian principle about falling bodies that conceives of bodies in an extremely liberal way. This chapter argues that this interpretation is implausible and then shows how the thought experiment might present (...) a challenge to a principle that conceives of bodies in a less permissive, more plausible way. The new interpretation of the thought experiment relies on a distinction between two ways of imagining Galileo’s experiment, one of which requires Aristotelians to temporarily ignore their belief in the principle under challenge. It is suggested that the distinction tracks an increasingly familiar distinction among dual-process theories in psychology: ‘intuitive’ and ‘reflective’ imagination. In order for Aristotelians to appreciate the thought experiment’s challenge to their theory, they are expected to use their intuitive imagination and not just their reflective imagination. (shrink)

The “Scientific Revolution” of the seventeenth century cannot adequately be assessed without an appreciation of the achievements and limitations of those, whether giants or dwarfs, on whose shoulders Galileo and his contemporaries stood. And since for many historians Galileo's main contribution lies in the mathematization of the natural world and especially of time and motion, particular interest attaches to medieval treatises dealing with these questions, above all to those which were in widespread demand early in the sixteenth century.

Galileo claimed inconsistency in the Aristotelian dogma concerning falling bodies and stated that all bodies must fall at the same rate. However, there is an empirical situation where the speeds of falling bodies are proportional to their weights; and even in vacuo all bodies do not fall at the same rate under terrestrial conditions. The reason for the deficiency of Galileo’s reasoning is analyzed, and various physical scenarios are described in which Aristotle’s claim is (...) closer to the truth than is Galileo’s. The purpose is not to reinstate Aristotelian physics at the expense of Galileo and Newton, but rather to provide evidence in support of the verdict that empirical knowledge does not come from prior philosophy.Author Keywords: Author Keywords: Aristotle; Galileo; Thought experiments; Falling bodies. (shrink)

The ArgumentWe present a number of findings concerning Galileo's major discoveries which question both the methods and the results of dating his achievements by common historiographic criteria. The dating of Galileo's discoveries is, however, not our primary concern. This paper is intended to contribute to a critical reexamination of the notion of discovery from the point of view of historical epistemology. We claim that the puzzling course of Galileo's discoveries is not an exceptional comedy of errors but (...) rather illustrates the normal way in which scientific progress is achieved. We argue that scientific knowledge generally develops not as a sequence of independent discoveries accumulating to a new body of knowledge but rather as a network of interdependent activities which only as a whole makes the individual steps understandable as meaningful “discoveries.”. (shrink)

For forty years, beginning with the publication of the first modern English translation of the Dialogue Concerning the Two Chief World Systems, Stillman Drake was the most original and productive scholar of Galileo's scientific work of our age. During that time, he published sixteen books on Galileo, including translations of almost all the major writings, and Galileo at Work, the most comprehensive study of Galileo's life and works ever written. His collection Discoveries and Opinions on Galileohas remained in (...) print since its appearance in 1957 and has become the most widely read of all books on Galileo. In addition to his books, Drake published about 130 papers, of which nearly 100 are on Galileo and the rest on related aspects of the history and philosophy of science. This three-volume collection includes eighty of those papers. Drake's papers are an essential supplement to his translations and other books because it was in his papers that he wrote his most detailed technical studies of Galileo's scientific work. There is hardly a subject in Galileo's science that is not considered. Perhaps the most important is the series on mechanics and motion, in which Drake analysed Galileo's manuscript notes recording the experiments by which he discovered and confirmed the law of the acceleration of falling bodies. There are also papers on the notes in which Galileo recorded his discovery of Jupiter's satellites and on other aspects of Galileo's astronomy, including his defence of the Copernican theory. Other papers consider Galileo's life and scientific work in general, exploring what Drake calls the 'scientific personality' of Galileo along with his scientific method and philosophy of science. In addition to the papers on Galileo, there are a number of papers on medieval and early modern science, principally on mechanics, and on the philosophers A.B. Johnson and J.B. Stallo, both of whom influenced Drake's own philosophy of science. (shrink)

This book is intended as a historical and critical study on the origin of the equations of motion as established in Newton's Principia. The central question that it aims to answer is whether it is indeed correct to ascribe to Galileo the inertia principle and the law of falling bodies. In order to accomplish this task, the study begins by considering theories on the motion of bodies from classical antiquity, and especially those of Aristotle. The theories developed (...) during the Middle Ages and the Renaissance are then reviewed, with careful analysis of the contributions of, for example, the Merton and Parisian Schools and Galileo's immediate predecessors, Tartaglia and Benedetti. Finally, Galileo's work is examined in detail, starting from the early writings. Excerpts from individual works are presented, to allow the texts to speak for themselves, and then commented upon. The book provides historical evidence both for Galileo's dependence on his forerunners and for the major breakthroughs that he achieved. It will satisfy the curiosity of all who wish to know when and why certain laws have been credited to Galileo. (shrink)

This book collects a renowned scholar's essays from the past five decades and reflects two main concerns: an approach to logic that stresses argumentation, reasoning, and critical thinking and that is informal, empirical, naturalistic, practical, applied, concrete, and historical; and an interest in Galileo’s life and thought—his scientific achievements, Inquisition trial, and methodological lessons in light of his iconic status as “father of modern science.” These republished essays include many hard to find articles, out of print works, and chapters which (...) are not available online. The collection provides an excellent resource of the author's lifelong dedication to the subject. Thus, the book contains critical analyses of some key Galilean arguments about the laws of falling bodies and the Copernican hypothesis of the earth’s motion. There is also a group of chapters in which Galileo’s argumentation is compared and contrasted with that of other figures such as Socrates, Karl Marx, Giordano Bruno, and his musicologist father Vincenzo Galilei. The chapters on Galileo’s trial illustrate an approach to the science-vs-religion issue which Finocchiaro labels “para-clerical” and conceptualizes in terms of a judicious consideration of arguments for and against Galileo and the Church. Other essays examine argumentation about Galileo’s life and thought by the major Galilean scholars of recent decades. The book will be of interest to scholars in philosophy, logic, philosophy of science, history of science, history of religion, philosophy of religion, argumentation, rhetoric, and communication studies. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Physics and Metaphysics in Descartes and GalileoBlake D. Duttonin his classic biography of Descartes, Charles Adam passes this judgment on the influence of Galileo’s condemnation on the development of Cartesian metaphysics:Sans la condemnation de Galilée, nous aurions eu tout de même la métaphysique de Descartes. Mais nous ne l’aurions problement pas eue sous la forme volumineuse qu’elle a prise avec toutes ces Objections et Reponses, qui font plus que (...) quintupler les Méditations primitives.1(AT XII, 306)While not charging Descartes with dissimulation, Adam argues that the metaphysics was developed to deflect attention from the heart of the Cartesian system—its mechanistic physics—which posed a direct challenge to the reigning Aristotelianism. In his words, it served primarily as a “tent... to cover the merchandise (le pavilion... couvrir la marchandise)”(AT XII, 306).2Adam is certainly not alone in pointing to the Galileo affair as grounds for raising suspicions about the role of the metaphysics in Descartes’ larger work. In a recent biography, itself destined to become a classic, Stephen Gaukroger takes a similar line, arguing that it was Galileo’s failure to convince his opponents through arguments drawn from natural philosophy that prompted Descartes to seek acceptance of his own natural philosophy though metaphysical legitimation. Had Galileo not been silenced there would have been no impetus for Descartes to have developed a metaphysical argument; natural-philosophical [End Page 49] arguments would have sufficed.3 Thus, in the words of Gaukroger, Descartes’ project of metaphysical legitimation was “a task which he never even contemplated before the condemnation of Galileo in 1633, and... was a direct response to that condemnation.”4 If we are to believe Adam and Gaukroger, then, Descartes was first and foremost a natural philosopher whose extended venture into metaphysics was primarily a strategic response to the events of 1633.Despite the many merits of this line of interpretation, I believe it is trouble-some insofar as it isolates Descartes’ reaction to the condemnation from both his criticisms of Galileo’s science and his views on the relation between science and theology. In doing so, it overstates the degree to which Cartesian science can itself be isolated from Cartesian metaphysics. In what follows, then, I will contextualize Descartes’ reaction to the Galileo affair by examining his comments on Galileo’s scientific work and the relation of his own views on science and theology to those of Galileo. Two results will emerge. First, we will see that if we fail to take Descartes’ search for metaphysical foundations as having a genuinely scientific motivation, not only will we render his criticisms of Galileo’s science unintelligible, but we will fail to understand the distinctive nature of his science vis-à-vis Galileo’s. This will become clear as we examine the work of each on motion and the fall of bodies. Second, we will see that it is only by taking Descartes’ metaphysical commitments as integral to his science that we can make sense of the divergent ways in which he and Galileo resolved the question of the relation of science to theology. Both, it is clear, sought to guarantee the autonomy of science, yet each did so in a way which mirrored his unique conception of science and its relation to metaphysics. All of this, I conclude, deflates the utility of appealing to Descartes’ concern over the Galileo affair as a means of assigning a primarily strategic or extra-scientific role to his metaphysics. [End Page 50]1. descartes on galilean scienceAlthough they were contemporaries, there is no evidence that Descartes and Galileo ever met or corresponded. There is also no strong evidence that the work of either had any significant influence on the work of the other, despite the fact that Descartes reports having leafed through the Dialogue Concerning the Two Chief World Systems and having obtained a copy of the Two New Sciences.5 However, we do find several references to Galileo in Descartes’ correspondence from which a general attitude toward the Italian scientist becomes reasonably clear. While occasionally being complimentary, Descartes appears to have been largely unimpressed and even claims to have arrived at several... (shrink)

The purpose of this study is to gain a better understanding of the role of abstraction and idealization in Galileo’s scientific inquiries into the law of free falling motion, and their importance in the history of science. Because there is no consensus on the use of the terms “abstraction” and “idealization” in the literature, it is necessary to distinguish between them at the outset. This paper will argue for the importance of abstraction and idealization in physics and the theories (...) and laws of physics constructed with abduction from observations and that these theoretical laws of physics should be tested with deduction and induction thorough quasi-idealized entities rather than empirical results in the everyday world. Galileo’s work is linked to thought experiments in natural science. Galileo, using thought experiments based on idealization, persuaded others that what had been proven true for a ball on an inclined plane would be equally true for a ball falling through a vacuum. (shrink)

The clearly recognized innovation in Galileo’s work on free fall has been a stimulus and a challenge for the history and philosophy of science. This article will analyze the experimental and theoretical aspects of Galileo’s work on free fall. It draws on several authors’ results to justify the claim that the research model established by Galileo remains valid today (Sections 2 and 3). The article draws this parallel with current science by focusing on Galileo’s method, way of considering scientific instruments, (...) and practice of confrontation between theory and experiments. The Galilean mode of investigation can be interpreted from a variety of possible philosophical perspectives: Section 3 examines how relevant the so-called constructivist and conventionalist perspectives are to analysis of Galileo’s innovations. Section 4 discusses Galileo’s contribution to the mathematization of science and the Platonic character of his thought. Finally, the article attempts to show that Galileo’s Platonism also involves experiments, as he conceives them. Keywords: Inclined Plane. Mathematics. Platonism. (shrink)

Gianantonio Tadini (1754–1830) is the little known protagonist in an important experiment carried out in Bergamo between 1794 and 1795. Based on the measurement of the deviation of a falling body, the experiment owes much to the one that was conducted by Giambattista Guglielmini (1760–1817) in Bologna in 1791, which aimed at demonstrating Earth’s rotation. Tadini’s experimental work represents the most successful attempt carried out before the 19th century, and it led to the first correct formulation of deviation’s measurement. (...) In spite of this, it is not well represented in the general literature on the history of experiments intended to show diurnal Earth’s motion.1 The discovery of Tadini’s diary of experiments as well as some notes and a part of his correspondence – preserved as manuscripts in the Angelo Mai municipal library in Bergamo – allows us now to reconstruct the history of Tadini’s experiment and of his reasoning about Guglielmini’s work. In this paper, I describe the genesis and the development of Tadini’s experiment, clarify the role played by the different personalities involved and set these trials against the background of the widest history of proofs on diurnal Earth’s rotation carried out in Europe in those years. (shrink)

Beginning with an overview of Galileo's earliest work on free fall, the paper examines the relationship between experiment and theory in his study of motion in the period immediately before and after 1604. The possible role of experiment is assessed in relation to the manuscript evidence and by means of reconstructed experiments.

The inductive problem of extending the sequence 1, 3, 5, 7, is solved when these numbers are the ratios of the incremental distances fallen in successive unit times. The controlling fact is Galileo’s assumption that these ratios are invariant under a change of the unit of time. It admits few laws and only one is compatible with the two-numbered initial sequence 1, 3.

Galileo's refutation of the speed-distance law of fall in his Two New Sciences is routinely dismissed as a moment of confused argumentation. We urge that Galileo's argument correctly identified why the speed-distance law is untenable, failing only in its very last step. Using an ingenious combination of scaling and self-similarity arguments, Galileo found correctly that bodies, falling from rest according to this law, fall all distances in equal times. What he failed to recognize in the last (...) step is that this time is infinite, the result of an exponential dependence of distance on time. Instead, Galileo conflated it with the other motion that satisfies this ‘equal time’ property, instantaneous motion. (shrink)

: Although Galileo's struggle to mathematize the study of nature is well known and oft discussed, less discussed is the form this struggle takes in relation to Galileo's first new science, the science of the second day of the Discorsi. This essay argues that Galileo's first science ought to be understood as the science of matter—not, as it is usually understood, the science of the strength of materials. This understanding sheds light on the convoluted structure of the (...) Discorsi's first day. It suggests that the day's meandering discussions of the continuum, infinity, the vacuum, and condensation and rarefaction establish that a formal treatment of the "eternal and necessary" properties of matter is possible; i.e., that matter as such can be considered mathematically. This would have been a necessary, and indeed revolutionary, preliminary to the mathematical science of the second day because matter itself was thought in the Aristotelian tradition to be responsible for the departure of natural bodies from the unchanging and thus mathematizable character of abstract objects. In addition, the first day establishes that when considered physically, these properties account for matter's force of cohesion and resistance to fracture. This essay closes by showing that this dual style of reasoning accords with the conceptual structure of mixed mathematics. (shrink)

In the ten years following the publication of Galileo Galilei's Discorsi e dimostrazioni matematiche intorno a due nuove scienze , the new science of motion was intensely debated in Italy, France and northern Europe. Although Galileo's theories were interpreted and reworked in a variety of ways, it is possible to identify some crucial issues on which the attention of natural philosophers converged, namely the possibility of complementing Galileo's theory of natural acceleration with a physical explanation of gravity; the (...) legitimacy of Galileo's methods of proof and of his theory of the composition of continuous magnitudes; and the adequacy of the experimental evidence in favor of his theory.Through his published works and his correspondence, Marin Mersenne contributed in a significant way to each of these discussions. In the following, I shall provide a sketch of Mersenne's multiple engagement with the new science of motion, while trying to account for his growing skepticism concerning Galileo's law of free fall. Whereas in the 1630s, Mersenne still firmly believed in the validity of this law and tried to devise experimental and mathematical proofs in its favor, in the 1640s he developed serious doubts regarding the possibility of constructing an exact science of motion. As we shall see, Mersenne's evolving attitude sheds an interesting light on his views concerning the relation between physics and mathematics.---------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ----------------------------------------------------. (shrink)

This article considers the research ethics appropriate to Paul Feyerabend’s notorious ‘methodological anarchist’ approach to the history and philosophy of science, concluding that it might be especially appropriate for our ‘post-truth’ times. The article begins by noting that Feyerabend favorite historical figure, Galileo, appears Janus-faced in his corpus. The article focuses on the positive image of someone who broke institutionalized rules of inquiry in pursuit of a ‘higher truth’ that was fully realized by Newton and his successors. The logic of (...) Galileo’s early seventeenth century situation was that decisions about permissible forms of inquiry and inference were based on mixed political and epistemic criteria – and that this was known, and sometimes admitted, by all parties. Galileo played with this ambiguity to some but by no means complete success, largely because he could not properly ground his ‘higher truth’. The article proceeds to show that Galileo’s situation was not unique but commonplace in the history of science, a point that has become clearer since the rise of archival historical research in the nineteenth century. Moreover, the institutional incentives to commit, cover up and detect what we now call ‘research fraud’ have been very uneven. Most such fraud has probably passed undetected sufficiently long to be incorporated in the body of accepted scientific knowledge. In recent years, however, increased attention has been given to research fraud due to the increased existential and financial stakes involved, which in turn have contributed to science’s larger legitimacy crisis in the post-truth era. The article ends on a Feyerabendian note, suggesting that research findings should include sunset clauses and statues of limitations. (shrink)

Hailed by the Journal of the History of Astronomy as "charming and witty," this chronicle by a renowned physicist traces the development of scientific thought from the works of the "founding fathers" — Galileo, Huygens, and Newton — to the more recent discoveries of Maxwell, Boltzmann, and Gibbs. 1984 edition.

Based on an examination of Galileo’s mechanics, Peter Machamer and Andrea Woody proposed the scientific use of what they call models of intelligibility. As they define it, a model of intelligibility is a concrete phenomenon that guides scientific understanding of problematic cases. This paper extends Machamer and Woody’s analysis by elaborating the semantic function of MOIs. MOIs are physical embodiments of theoretical representations. Therefore, they eliminate the interpretive distance between theory and phenomena, creating classes of concrete referents for theoretical concepts. (...) Meanwhile, MOIs also provide evidence for historical analyses of concepts, like ‘body’ or ‘motion’, that are otherwise thought to be too basic for explicit explication. These points are illustrated by two examples also drawn from Galileo. First, I show how the introduction of the balance as an MOI leads Galileo to reject the Aristotelian conception of elemental natures. Second, Galileo’s rejection of medieval MOIs of circular motion constrains the reference of ‘conserved motion’ to curvilinear translations, thereby excluding the rotations that had been included in its scope. Both uses of MOIs marked important steps toward modern classical mechanics. (shrink)

Based on an examination of Galileo’s mechanics, Peter Machamer and Andrea Woody (and Machamer alone in subsequent articles) proposed the scientific use of what they call models of intelligibility. As they define it, a model of intelligibility (MOI) is a concrete phenomenon that guides scientific understanding of problematic cases. This paper extends Machamer and Woody’s analysis by elaborating the semantic function of MOIs. MOIs are physical embodiments of theoretical representations. Therefore, they eliminate the interpretive distance between theory and phenomena, creating (...) classes of concrete referents for theoretical concepts. Meanwhile, MOIs also provide evidence for historical analyses of concepts, like ‘body’ or ‘motion’, that are otherwise thought to be too basic for explicit explication. These points are illustrated by two examples also drawn from Galileo. First, I show how the introduction of the balance as an MOI leads Galileo to reject the Aristotelian conception of elemental natures. Second, Galileo’s rejection of medieval MOIs of circular motion constrains the reference of ‘conserved motion’ to curvilinear translations, thereby excluding the rotations that had been included in its scope. Both uses of MOIs marked important steps toward modern classical mechanics. (shrink)

In this paper Galileo’s we seek to follow Galileo’s mind as he constructs the principle of the complete isochronism of the pendulum from experimental observations and theoretical demonstrations. Our conclusion will be that the principle came from experiments with relatively small angle pendulums, coupled with a „leap“ from free fall along circular chords and ideas about the natural frequencies of physical systems. The pendulum experiments of the First and Fourth Day were, in all probability, never performed. The results claimes were (...) simply illustrations of the isochronism principle. (shrink)

In this essay, I shall argue that Galileo introduced a new scientifically useful notion of causality. This new notion of causality was an interventionist notion, according to which causal relations can be discovered by actively exploring and manipulating natural processes. The presence of this conception can be seen from Galileo's explanation of floating bodies and his theory of the tides. I shall point to the similarity between Galileo's notion of "cause" and recent interventionist accounts of causation in (...) the philosophy of science (especially James Woodward's). (shrink)

Recent debates about thought experiments have focused on a perceived epistemological problem: how do thought experiments manage to provide knowledge when they yield no new empirical data? A bold answer to this question is provided by James Robert Brown’s platonisrn, according to which a certain class of thought experiments allow a sort of intellectual perception of laws of nature, understood as relations between universals. I suggest that there are three main problems with platonism. First, it is restricted to a very (...) small class of thought experiments; hence, it largely fails to address the general epistemological problem. Second, it is not quite clear what it is supposed to explain. Third, its explanatory value in any case seems dubious, since the mechanisms it postulates (i) appear to raise issues more ditficult than what they would explain, and (ii) seem to obviate the very need for conducting thought experiments. I also argue that it fails to give an accurate account of Brown’s flagship example, Galileo’s thought experiment on falling bodies. In conclusion, I suggest that although platonism about thought experiments is an exciting thesis, it is at present unconvincing. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:Hispanic Philosophy in the Age of Discovery ed. by Kevin WhiteIván JaksicKevin White, editor. Hispanic Philosophy in the Age of Discovery. Washington, DC: Catholic University of America Press, 1997. Pp. xv + 326. Cloth, $59.95.The quincentennial of what has been termed the “encounter” between Europeans and Indians in the New World in the late fifteenth century furnished the occasion for much denunciation of the evils inflicted by greedy (...) intruders on the indigenous population and their environment. Many a conference was convened to reflect on such [End Page 463] events from the perspective of what appeared to be a consensus on the ultimately negative effects of European discovery, conquest, and colonization. In this context, it is quite remarkable that a conference on Hispanic philosophy in the age of discovery should have been convened to examine the philosophical figures and treatises of the era. As it turns out, this volume represents probably one of the most enduring outcomes of the myriad activities of 1992. This is a volume that ranges widely into the philosophical world of the period, brings to light the richness and significance of philosophers and their work, and provides a coherent and consistently well-researched set of essays.The volume consists of fifteen essays divided into five parts. Part I consists of one essay by Jorge J. E. Gracia which offers a wide panorama of Hispanic philosophy from 1500 to 1650, as well as a lucid interpretation of the historical reasons why Hispanic philosophy seems to have reached a dead end in the context of modern European philosophy, and suffered the neglect of intervening centuries. Part II consists of one essay by Mauricio Beuchot on discussions concerning the conquest of Mexico; two essays by John Doyle and Marcelo Sánchez-Sorondo on the work of Francisco de Vitoria; and two essays on the celebrated dispute between Juan Ginés de Sepúlveda and Bartolomé de las Casas in 1550–51, the first by Eduardo Andújar and the second by Rafael Alvira and Alfredo Cruz. Part III includes essays by William Wallace on Domingo de Soto and Galileo’s science; Juan Antonio Widow on the economic thought of the Spanish Scholastics; Jean de Groot on the mysticism of Teresa de Avila; Yves Floucat on St. John of the Cross, and Mirko Skarica on the problem of future contingents. Part IV includes three essays by Norman Wells, Stephen Menn, and Carlos G. Noreña on the works of Francisco Suárez, probably the best-known Spanish thinker of the period. The volume closes with Part V, which has a long essay by John Deely on John Poinsot’s doctrine of signs.A volume of this scope and nature is bound to contain some overlap and repetition, as is the case with the pieces concerning the Las Casas-Sepúlveda debate. And yet these essays read well because the authors seriously undermine the conventional treatment of Sepúlveda as the hawkish defender of Indian slavery, and place him in the context of a larger Renaissance view of non-European peoples. Las Casas, in the view of the authors, had a great deal more in common with his opponent than the historiography has thus far suggested. In other sections of the volume, the variety of approaches and subjects on the part of the contributors challenges the reader to constantly shift grounds. Part III, for instance, takes us from the disquisitions on the velocity of falling bodies to the moral aspects of economic thought, and to the meaning of mystical theology. Fortunately, the competence of the researchers makes all individual pieces worthwhile even if this particular reviewer would have been somewhat more stringent with the space allotted to make a point.Contributors to this book leave no doubt as to the importance of their subjects, and yet they resist the temptation of exaggerating the extent of the influence of many of the Spanish authors on other European thinkers. Indeed, the essay by Norman Wells shows that while one must consider the linkages between Suárez and Descartes, there is [End Page 464] no reason to believe that the latter made Suárez’s position on the moderni... (shrink)

This article analyzes Galileo's mathematization of motion, focusing in particular on his use of geometrical diagrams. It argues that Galileo regarded his diagrams of acceleration not just as a complement to his mathematical demonstrations, but as a powerful heuristic tool. Galileo probably abandoned the wrong assumption of the proportionality between the degree of velocity and the space traversed in accelerated motion when he realized that it was impossible, on the basis of that hypothesis, to build a diagram of the (...) law of fall. The article also shows how Galileo's discussion of the paradoxes of infinity in the First Day of the Two New Sciences is meant to provide a visual solution to problems linked to the theory of acceleration presented in Day Three of the work. Finally, it explores the reasons why Cavalieri and Gassendi, although endorsing Galileo's law of free fall, replaced Galileo's diagrams of acceleration with alternative ones. (shrink)

In Il Saggiatore (1623), Galileo makes a strict distinction between primary and secondary qualities. Although this distinction continues to be debated in philosophical literature up to this very day, Galileo's views on the matter, as well as their impact on his contemporaries and other philosophers, have yet to be sufficiently documented. The present paper helps to clear up Galileo's ideas on the subject by avoiding some of the misunderstandings that have arisen due to faulty translations of his work. (...) In particular, it shows how Galileo's distinction directly implicates a novel understanding of physical bodies, which played an important part in his later condemnation by the Catholic Church. At the same time, the paper also argues that Galileo's distinction can already be found in the text and illustrations of earlier, popular Copernican writings. (shrink)

Over the past twenty years the expression “thought experiment” (Gedankenexperiment) has become part of the philosophical vocabulary. Galileo’s thought experiment on the fall of bodies is an example that shows how thought experimentation might be an important scientific tool in order to acquire new knowledge. Nonetheless, the epistemological validity of thought experiments is still questioned in the domains different from physics. The paper aims to investigate whether the thought experimentation is really proper to physics. For this sake, biology will (...) be our testbed. The skeptical view on biological thought experiments, e.g. Snooks, implies that the thought experiment is not an experiment; it is just the copy of a real one. We adopt a more positive view, inspired by Bokulich and Lennox, and we apply it to some Darwinian thought experiments. This analysis points to the fact that, much alike thought experiments in physics, Darwin’s ones in biology test the non-empirical criteria of a theory. Therefore, we advance the hypothesis that even biological thought experiments participate to such a re-ordering of processes and mechanisms, as to push a theory beyond its time. (shrink)

I provide some considerations on scientific thought experiments, focusing on their epistemic value. First, I outline the distinctive features of scientific thought experiments, provide some historical background and, as an illustration, describe two thought experiments: Galileo's on falling bodies and Stevin's on inclined plane. I take thought experiments in physics as an example from which more general conclusions can be drawn - about thought experiments in other natural sciences, but also in philosophy, mathematics, and other sciences. Further, (...) I present Kuhn's epistemic puzzle as well as some proposed solutions. This closely relates to the question what kind of processes are involved in scientific thought experimenting. The satisfactory answer must consider scientific discoveries. I outline the mental model account as the most promising account since it best incorporates the findings of cognitive science. I conclude with two issues that the account needs to resolve and the role cognitive science can play in this. (shrink)

This paper is a case study. After formulating three norms for critical assessment of argumentation (section 1), I give a brief overview of Galileo’s argumentative strategy in his Dialogue and present his argument for the cause of the tides, which appears as an argument by analogy (section 2). I then discuss possible reconstructions of this argumentation, with one particular suggestion in detail. These arguments seem to fall short, given the aforementioned set of norms (section 3). This leads to my own (...) proposal of Galileo’s argument. I defend this proposal and it’s general idea - that is, the argument’s pattern. It will be classified as ‘interventionist’ and useful regarding the goals of critical assessment (section 4). Finally, I suggest that the pattern of argument is applicable to other cases and useful for applied theory of science (section 5). (shrink)