Skip to main content Accessibility help

Experience and Experiment: A Comparison of Zabarella's View with Galileo's in De Motu *

  • Charles B. Schmitt (a1)


‘Quoad congeriem vero, conficimus historiam non solum naturae liberae ac solutae (cum scilicet ilia sponte fluit et opus suum peragit), qualis est historia coelestium, meteororum, terrae et maris, mineralium, plantarum, animalium; sed multo magis naturae constrictae et vexatae; nempe, cum per artem et ministeriurn humanum de statu suo detruditur, atque premitur et fingitur.’

—Francis Bacon, Novum Organum (1620), ‘Distributio operis, pars tertia’

‘Experimentum est experientia, quae versatur circa facta naturae, quae nonnisi interveniente opera nostra contingunt.’

—Christian Wolff, Psychologia empirica (1732)

One of the tendencies which clearly marked the intellectual development of the seventeenth century was an increasing emphasis on experience. In philosophy this took the form of an empiricism which developed progressively from Gassendi to Locke; in science there emerged ever more clearly a definable ‘experimental method’, which was progressively refined from Francis Bacon to Newton. By the end of the seventeenth century the classic works illustrating these tendencies had appeared and set the trend for much of eighteenth-century intellectual activity.



Hide All

This paper is partly an outgrowth of research carried out with the aid of Grant No. 3809, Penrose Fund, American Philosophical Society. The generosity of this assistance is gratefully acknowledged. In one form or another it has been read on the following occasions: (1) 4 April 1967, to the Columbia University Seminar on the Renaissance; (2) 24 May 1968, to the Seminar on Methodology at University College, London; and (3) 5july 1968, to the British Society for the History of Science, Summer Meeting at Leeds University. In preparing it I have benefited greatly from the many helpful suggestions, criticisms, and comments of a number of scholars, especially the following: William F. Edwards, Neal W. Gilbert, Donald R. Kelley, Paul Oskar Kristeller, Edward P. Mahoney, J. R. Ravetz, Edward Rosen, William R. J. Shea, and Charles Webster.



Hide All

1 I do not mean to imply that this was the only tendency in 17th-century thought or even the dominant one, but merely to indicate that it was one of a number of approaches to knowledge and understanding which became increasingly important in the course of the century. For an example of a very different tendency which manifested itself at the same time see Schmitt, Charles B., ‘Perennial Philosophy: From Agostino Steuco to Leibniz’ Journal of the History of Ideas, XXVII 1966, 505532

2 Of the large literature we might cite the following: Caverni, R., Storia del metodo sperimentale in Italia (Florence, 1891-1898); Hanschmann, Alexander Bruno, Bernard Palissy: der Künstler, Naturforscher, und Schriftsteller, ah Vater der induktiven Wissenschaftsmethode des Bacon von Verulam (Leipzig, 1903); Lynn Thorndike, History of Magic and Experimental Science (8 vols., New York, 1923-1958); Carton, Raoul, L'expérience physique chez Roger Bacon (Paris, 1924); J. H. Randall, Jr., ‘The Development of Scientific Method in the School of Padua’, Journal of the History of Ideas 1 (1940), 177-206 [reprinted in a more definitive form in Randall’s The School of Padua and the Emergence of Modern Science (Padua, I961),pp. 15-68]; A. C. Crombie, Robert Grosseteste and the Origins of Experimental Science (Oxford, 1953); William A. Wallace, The Scientific Methodology of Theodoric of Freiberg (Fribourg, 1959); D. E. Gershenson and Greenberg, D. A., Anaxagoras and the Birth of Scientific Method (New York, 1964); Valdarini, Angelo, Il metodo sperimentale da Aristotele a Galileo, 3rd ed. (Bologna, 1920).

3 ‘The Development of Scientific Method …’, in The School of Padua and the Emergence of Modern Science, pp. 15-68. All further references will be to this edition, unless otherwise noted.

4 The most recent student of 16th-century logic as a whole also points out Zabarella's importance: ‘Der bedeutendste dieser italienischen Aristoteliker und zweifellos der Hohepunkt der Paduaner Schule ist Zabarella, einer der scharfsinnigsten und klarsten Logiker aller Zeiten.’ Risse, Wilhelm, Die Logik der Neuzeit: I. Band, 1500-1640 (Stuttgart- Bad Cannstatt, 1964), 278 . See also William F. Edwards, The Logic of Iacopo Zabarella (1533-1580) (New York: Columbia University Dissertation, i960) and Petersen, Peter, Geschichte der aristotelischen Philosophie improtestantischen Deutschland (Leipzig, 1921).

5 Das Erkenntnisproblem in der Philosophic und Wissenschaft der neueren Zeit, 2nd ed. (Berlin, 1911-1923), 1, 136-143. See also Wiener, P. P., ‘The Tradition behind Galileo’s Methodology’, Osiris, 1 (1936), 733746 , at 741.

6 Cassirer, op. cit., I, 139: ‘Mit dieser BegrifFsbestimmung der Erkenntnis aber weist Zabarella bereits deutlich auf Galilei voraus. Auf ihn deutet nicht nur die Scheidung von “kompositiver” und “resolutiver” Methode, sondern vor allem die tiefere und reinere Abgrenzung von populärer Beobachtung und wissenschaftlicher Erfahrung … . Alle diese Ausführungen sind von Galileis Methodenlehre, in der wir sie völlig gleichlautend wiederfinden werden, nur durch einen einzigen Zug getrennt, der allerdings entscheidend ist.’ Randall, op. cit., p. 27: ‘It is possible to trace step by step in rather beautiful fashion the gradual elaboration of the Aristotelian method, in the light of the medical tradition, from its first discussion in Pietro d'Abano to its completed statement in the logical controversies of Zabarella, in which it reaches the form familiar in Galileo and the seventeenth century scientists.’

7 Cassirer, op. cit., 1, 139-140: ‘Die Rolle, die der Mathematik in der “beweisenden Induction“ zukommt, wird von Zabarella nirgends begriffen: die Beispiele, auf die er sich fur seine neue Grundanschauung beruft, sind nicht der exakten Wissenschaft, die erst in vereinzelten Ansätzen vorlag, sondern der Metaphysik und Naturlehre des Aristoteles entnommen.’ Randall, op. cit., 65: ‘There is but one element lacking in Zabarella's formulation of method: he did not insist that the principles of natural science be mathematical, and indeed drew his illustrations largely from Aristotle's biological subject matter.’ Incidentally, one must use all of the redactions of Randall's article to get a comprehensive picture of his view. Gilbert, Neal W., ‘Galileo and the School of Padua’ ’Journal of the History of Philosophy, I 1963, 223231 at 227n4, has pointed out one change made by Randall in a later version of the article, but there are others, as, for example, the curious one discussed below in n. 57.

8 Art cit. Professor Gilbert, however, is not quite right in asserting that ‘there is no mention of Zabarella in the whole mass of Galileo's writings’ (p. 224), for there seems to be at least one. See Antonio Favaro, ‘Capitolo inedito e sconosciuto di Galileo Galilei contro gli aristotelici’, Atti del Reale Istituto Veneto di scienze, lettere ed arti, ser. vn, ni (1891-1892), 1-12, at p. 8, which reads: ‘Fioriro un tempo il padovano nido un Zabarella, un Mainetto, un Speroni’ This poem, not included in the national edition of the Opere was written about 1623. I an indebted to Professor William F. Edwards for calling this to my attention. See n. 7, p. 66 of Professor Edwards’ article cited below in my n. 137.

9 Op. cit., p. 61.

10 Ibid., p. 55. In the view of the present writer Zabarella is not so far from the Schoolmen as Randall claims and is certainly in many ways much closer to the 13th- and 14thcentury Schoolmen than to Galileo regarding questions of method. See Gilbert, Neal W., Renaissance Concepts of Method (New York, 1960), p. 173 .

11 For the peripatetic background of Galileo's language in the Italian works see Maria Luisa Altieri Biagi, Galileo e la terminologia tecnico-scientifica, in Biblioteca dell’ Archivium Romanicum, ser. n, 32 (1965), 25-41. The conclusions of this study, which is based on the Italian works of Galileo, is that, although Galileo did not reject wholesale the significant scientific terms used before him, he had a strong tendency to refuse to use the Aristotelian terminology. It must be said, however, that the De motu betrays significantly more Aristotelian elements in terminology, as well as in doctrine, than do the mature Italian works. Galileo's key methodological terms, viz. metodo risolutivo and metodo compositivo, are, of course, traditional Aristotelian usages and are to be found in their Latin form in Zabarella, as Cassirer and Randall have pointed out.

12 If Galileo was influenced by Zabarella before he arrived in Padua it must have been through the Opera logica (1st ed., Venice, 1578). The De rebus naturalibus, which utilizes many interesting experientiae, as we shall see below, was not printed until 1590, by which time the De motu had probably been completed.

13 For some indications see our conclusions below, pp. 110-114.

14 E.J. Dijksterhuis, The Mechanization of the World Picture, trans. C. Dikshoorn (Oxford, 1961), pp. 138-140.

15 Eugenio Garin, Medioevo e Rinascimento, 2nd ed. (Bari, 1961), pp. 150-191, esp. pp. 158-159, 188-190; Nauert, Charles G., Jr., Agrippa and the Crisis of Renaissance Thought (Urbana, 1965), pp. 214215 .

16 Nauert, op. cit., p. 215, citing from Agrippa's De occulta philosophia, 1, Ch. 10. 17 For a 16th-century example see Ringelbergius, Ioachim Fortius, Lucuhrationes vel potius absolutissima Kvkƛoπaíδειa … (Basel, 1541), p. 719 .

18 ‘Ad curandam ictiteiam [!] proprium experimentum recipe (?) rasure eboris, succi epatice … ,’ Summa experimentorum sive thesaurus paupemm magistri Petri Yspani [Antwerp, 1497], f. d2r. As an example of the range of materials included during the Middle Ages under the categories of experimentum and experientia see Bridges, John Henry, ed., The'Opus Majus’ of Roger Bacon (Oxford, 1897), II, 167-222, pars sexta: De scientia experimentali.

This is a very mixed bag, including materials on rainbows, medicine, alchemy, and explosives, among other things. See also Lynn Thorndike, A History of Magic and Experimental Science (New York, 1923-1958), II, 435-448 (on Albert the Great); II, 854- 855 (on Arnold of Villanova); and n, 906 (on Pietro d'Abano), which illustrates the wide diversity of meaning among the various usages of experientia and experimentum. The discussions of Arnold of Villanova and Pietro d'Abano clearly indicate that experience is considered to reveal to us information which cannot be reached through reason. A most significant example of the way experimentumwzs sometimes used in the Middle Ages is to be found in a document of the acts of the Dominican Chapitre provincial de Bordeaux, dated 15 August 1311 [from the Bibliothéque publique de la ville de Toulouse, MS. 490 (I, 273), f. 4I2v]. It reads as follows: ‘Item, prior provincialis, de consilio diffinitorum, in virtute sancte obedientie precipit omnibus fratribus habentibus libros nigromanticos, experimenta, conjurationes et quecumque scripta supersticiosa, quod infra VIII dies ab audientia vel notitia hujus precepti, prioribus suis vel eorum loca tenentibus ea tradant, et ipsi priores vel eorum loca tenentes priori provinciali ea tradant quam cito eis fuerit oportunum.’ As cited in C. Douais, Les frères prêcheurs en Gascogne au XIIIe et au XIVe siècle (Paris, 1885), p. 121. My attention was called to this by K. W. Humphreys, The Book Provisions of the Mediaeval Frairs, 1215-1400 (Amsterdam, 1964), p. 43. The failure to distinguish the two terms in the medical literature is clearly brought out in the 16th-century medical lexicon, Joannes Gorraeus, Definitionum medicarum libri XXIV Uteris Graecis distincti … (Frankfurt-am-Main, 1578), f. 364v, which reads as follows: Experimentum sive experientia. Vocabulum est empericorum proprium. Significat autem eius frequenter et eodem modo visum est, comprehensionem atque memoriam; vel definire potes, experientiam esse eius quod eodem modo visum est, observationem atque memoriam. Idem vero est observatio atque experientia. Galeni de optima secta. Est et experientia, quam quasi iam tritam experientiam appellabant, ab experimentali disciplina ductam, experimentalem vero disciplinam vocabant eorum habitum quae ita frequenter apparuerunt, ut iam inde theorematasintcomparata, perceptumque numquid ilia semper aut plerumqueaut utrovis modo, aut raro evenire soleant. Scribit Galenus libello de subfiguratione empirica.’ It is interesting to note that the first edition of Gorraeus’ (1505-1577) work, printed at Paris by Andre Wechel in 1564 has no entry under . It was added only in the second edition published posthumously. For an interesting example in English see OED, III, n, 429c (Experiment), which shows that in Wyclif's Bible (Genesis, XLII, 15) a 1382 redaction has ‘experyment’, while the 1388 version has ‘experience'in the same passage. The vulgate has experimentum. The evidence seems to indicate that a highly developed sense of experiment and a clearer distinction between ‘experience’ and ‘experiment’ was current in medieval Arabic thought. See the important paper, A. I. Sabra, ‘The Astronomical Origin of Ibn al-Haytham's Concept of Experiment’, forthcoming in Actes du XIVe congrès international d'histoire des sciences (Paris, 1968). I am indebted to Dr. Sabra for allowing me to see his paper before its publication.

19 This is to be found in Buridan's Questiones super octo phisicorum libros Aristotelis, Book vm, question 12. A modern edition of the relevant passage is to be found in Maier, Anneliese, Zwei Grundprobleme der scholastischen Naturphilosophie (Rome, 1951), pp. 207214 . For an English translation and a discussion of its significance see Marshall Clagett, Science of Mechanics in the Middle Ages (Madison, 1959), pp. 533-534, 538.

20 By this I mean that it cannot directly utilize ‘experiments’ in the sense of observational situations designed by an experimenter and making use of artificial boundary conditions, controlled variables, etc. The classic distinction between ‘observational’ and ‘experimental' sciences is due, of course, to Bernard, Claude, Introduction à I'étude de la médecine expérimentale (Paris, 1865).

21 See especially the examples cited in Johnson, Francis R., Astronomical Thought in Renaissance England (Baltimore, 1937) and Jones, Richard Foster, Ancients and Modems, 2nd ed. (Berkeley and Los Angeles, 1965), pp. 322 .

22 ‘… utqui neque alias ex una atque altera sectione quicquam affirmare soleam.’ Andreas Vesalius, Epistola, rationem modumque propinandi radicis Chynae decocti … (Basel, 1546), p. 139. Cf. Moritz Roth, Andreas Vesalius Bruxellensis (Berlin, 1892), p. 108 and C. D. O'Malley, Andreas Vesalius of Brussels: 1514-1564 (Berkeley-Los Angeles, 1964), p. 116, who cites an incorrect page number. This aspect of the medical tradition is neatly expressed in Ioannis Gallego de la Serna … Recte ac dogmatice medendi vera methodus …(Paris, 1639), p. 1, which succinctly states: ‘eadem scilicet observatio sive experientia saepius repetita’. This work as a whole has much of interest with regard to problems of methodology. Here again (e.g. pp. 289-290) the terms experimentum and experientia are used in an interchangeable way.

23 See Straus, William L. Jr. and Temkin, Owsei, ‘Vesalius and the Problem of Variability’, Bulletin of the History of Medicine, XIV (1943), 609633 .

24 ‘… turn demum misere collabi coepit [scil. medicina], quum ipsi [i.e., medici] manum munus ad alios reijcientes, perdiderunt, Anatomen.’ Andreae Vesalii… De humani corporis fabrica libri septem (Basel, 1543), f. *2v.

25 Of the now large literature on this subject the following should be especially noted: Leonardo Olschki, Geschichte der neusprachlichen wissenschaftlichen Literatur (vol. 1: Die Literatur der Technik und der angetvandten Wissenschaften vom Mittelalter bis zur Renaissance, Heidelberg, 1918; n: Bildung und Wissenschaft im Zeitalter der Renaissance in Italien, Leipzig, 1922; III: Galilei und seine Zeit, Halle, 1927); Zilsel, Edgar, ‘The Origin of William Gilbert's Scientific Method’ Journal of the History of Ideas, II 1941, 132 idem, “The Sociological Roots of Science'American Journal of Sociology, XLVII 1942, 544562 Rupert Hall, ‘The Scholar and the Craftsman in the Scientific Revolution’, in Marshall Clagett, ed., Critical Problems in the History of Science (Madison, 1962), pp. 3-23; Adriano Carugo and Ludovico Geymonat, T così detti “esperimenti mentali” nei discorsi galileiani ed i loro legami con la tecnica’, in Actes du symposium international des sciences physiques et mathématiques dans la première moitié du XVIIe siècle (Vinci-Paris, s.d., c. 1962), pp. 35-47; Lynn White, Jr., ‘Pumps and Pendula: Galileo and Technology’, in Golino, Carlo, ed., Galileo Reappraised (Berkeley and Los Angeles, 1966), pp. 96110 .

26 Francisci Bonamici… De motu libri X quibus generalia naturalis philosophiae principia summo studio collecta continentur . .. (Florence, 1591). The dedication letter (fs. a2r-a3v) is dated 1587. This work has not been very much studied by modern scholars, but see Koyré, Alexandre, Études galiléennes (Paris, 1939), 1, II , 18-41.

Buonamici's work seems to form the basis of Galileo's so-called Juvenilia, which are apparently his notes taken when he was a student in Buonamici's classroom. On the similarities between Buonamici's De motu and Galea's Juvenilia see Favaro, Antonio, ‘Di alcune scritture giovanili di Galileo’, Atti e memorie della R. Accademia di scienze, lettere, ed arti in Padova XXXVII (1921), 611 .

27 ‘Magna etiam vis est experientiae quae nascitur ex memoria rerum quas sensus semel atque iterum suppeditat; nanque ex repetita sensione memoria propagatur. Multae eiusdem rei memoriae potestatem unius experientiae faciunt, ex experimentis vero primorum principiorum cognitio gignitur … Principia quae secundum unumquodque sunt, experimenti esse tradere: ut puta, astrologicae disciplinae principia ex astrologica experientia colliguntur … .’ Ibid., p . 4. This discussion continues for the next dozen or so lines, with the two terms continually used in the same haphazard way. Buonamici's discussion here recalls the final chapter of the Posterior Analytics, esp. iooa5-9. His text here seems to conflate two different traditions of translation of the Aristotelian term ., i.e., experimentum and experientia. The former, which occurs in the so-called versio communis of the work (see G. Lacombe et al., Aristoteles Latinus, pars prior [Rome, 1939], pp. 122-124), w a s used, for example, in the commentaries on Posterior Analytics, 11, 19 by Thomas Aquinas, Opera omnia … (Rome, 1882f.), 1,401; Albertus Magnus, Opera omnia (Paris, 1890-1899), n, 230; and Augustinus Niphus, Posteriorum analyticorum subtilissima commentaria (Venice, 1553), f. 79. Experientia, which occurs in Argyropulos’ translation of the work, was used, for example, by Schegk, Jacobus, De demonstratione libri XV … (Basel, 1564), p. 432 ; Soto, Dominicus, In librosposteriorum Aristotelis sive de demonstratione . . . (Venice, 1574), p . 548 ; and Iacobus Zabarella, In duos libros Aristotelisposteriores analyticos commentarii (Venice, 1582), f. 169v. The two terms are used interchangeably by Venetus, Paulus, In libros posteriorum Aristotelis … (Venice, 1491), Sig. mm6. Although we cannot here be exhaustive in this matter, the indication is that the two terms were not clearly distinguished, but both were used to render Aristotle's iinreipla without consistent distinction. Also see nn. 18, 22, and 30.

28 A brief survey of the situation is given in my ‘Changing Conceptions of Vacuum (1500-1650)’, Actes du XIe congrès international d'histoire des sciences (Warsaw, 1968), III, 340-433. A more detailed analysis of the experimental question is in my ‘Experimental Evidence for and against a Void: The Sixteenth-Century Arguments’, Isis LVIII (1967), 352-366.

29 For a sampling of the usages in the sixteenth-century discussions of vacuum see: Cardano, Girolamo, De subtilitate, in Opera Omnia (Lyon, 1663), III, 360; Commentarium Collegii Conimbrkensis Societatis Iesu in octo libros physicorum Aristotelis Stagiritae secunda pars (Lyon, 1602), cols. 90, 95; Julius Pacius, Aristotelis … naturalis auscultationis libri VIII (Frankfort, 1596), 604-605; Francesco Patrizi, Nova de universis philosophia (Venice, 1593), part II, f. 64v; de Soto, Domingo, Super octo libros physicorum Aristotelis quaestiones (Salamanca, 1582), f. 65v; Franciscus Toletus, Commentaria .. . in octo libros Aristotelis dephysica auscultatione (Lyon, 1580), p. 452; Bernardino Telesio, De rerum natura (Modena, 1910- 1923), 1, 88. It is interesting to note that one of the most vehement and learned anti-Aristotelians of the sixteenth century, Gianfrancesco Pico della Mirandola, considered Aristotle's positive contributions to lie in his attention to detail and his exhaustive experiments, rather than in his theoretical contributions to philosophy inon tarn doctrina, quam eximia cura ac diligentibus experimentis). See Examen vanitatis, iv, prooem., in Ioannis Francisci Pici … Opera … (Basel, 1601), p. 639 and Charles B. Schmitt, Gianfrancesco Pico della Mirandola (1460,-1533) and His Critique of Aristotle (The Hague, 1967), pp. 59, 72-73. Pico, of course, here shows his sceptical orientation, according to which direct observations (experimenta) are valued much more highly than is theorizing.

30 See for example the fifteenth-century treatise of Giovanni d'Arezzo entitled De medicinae et legum praestantia in Garin, Eugenio, ed., La disputa delle arti nel Quattrocento (Florence, 1947), pp. 35101 , esp. pp. 52, 58-66. We read for example: ‘Sed si his vulgus mordeas verbis, cum nulla sit evasio, ad experimenta fugam arripiunt. Vidisse enim ferunt, ut iam plerumque explorare coepi, experientias incredibiles …’ (p. 52). See also the text cited above in n. 18.

31 On Zabarella see especially Edwards, op. cit. and idem, ‘Zabarella’, in Enciclopedia filosofica (Venice-Rome, 1958), pp. 1811-1813, which cite the other relevant literature up to about 1958. Since then, the following have appeared which are also of value: J. J. Glanville, ‘Zabarella and Poinsot on the Object and Nature of Logic’, in Readings in Logic, ed. R. Houde (Dubuque, 1958), pp. 204-226; Gilbert, Renaissance Concepts of Method, pp. 167-176; Edwards, W. F., ‘The Averroism of Iacopo Zabarella’, Atti del XII congresso internazionale difiloscfia (published, Florence, 1960), IX, 91107 ; Corsano, Antonio, ‘Per la storia del pensiero del tardo Rinascimento, x: Lo strumentalismo logico di I. Zabarella’, Giornale critico della filosqfia italiana XLI (1962), 507517 ; di Napoli, Giovanni, L'immortalita dell'anima nel Rinascimento (Turin, 1963), pp. 376379 ; Wilhelm Risse, op. cit., pp. 278-290; Pra, Mario dal, ‘Una “oratio” programmatica di G. Zabarella’, Rivista critica di storia della filosqfia xxi (1966), 286290 .

32 Zabarella, Iacobus, Opera logica (Frankfurt, 1623), cols. 1267-1273, esp. 1269-1270. For a recent and detailed study of the question in Aristotle see Bourgey, Louis, Observation et expérience chez Aristote (Paris: Vrin, 1955).

33 Book n, chapters 8-10.1 use the following edition: Zabarella, Iacobus, De rebus naturalibus libri XXX (Frankfurt, 1617), cols. 361-374. This deals with the question: An motus misti factus secundum prevalens elementum sit simplex, an mistus … .

34 ‘Experientia quoque hanc sententiam confirmat, nam aedificatores utuntur linea perpendiculari simplici, quam inveniunt per plumbum vel lapidem capiti funis alligatum. Haec enim sunt mista corpora et ad centrum feruntur gravitate elementi praevalentis per lineam perpendicularem, quae simplex est, omnis enim recta linea ad centrum protenta simplex est. Parietes quoque aedificiorum, nisi ad perpendicularem [text: perpendicularum] sint fabricati [text: fabricari], durare diu nequeunt, sed aliquando cadunt et per lineam perpendicularem deorsum feruntur; et omnino docet experientia, non minus mista gravia, quam elementa, per simplicem lineam descendere.’ Ibid., n, 9, cols. 370-371. The bulk of Zabarella's polemic at this point is against Agostino Nifo. See Nifo's In Aristotelis libros de coelo et mundo commentaria (Venice, 1567), pp. 12-13, Book 1, texts 8-9. The origin of the problem goes back to Aristotle's De coelo, 1, texts 7-8 (258b27f). The handling of the question by earlier commentators also, in some cases, shows some reHance on experience. We do not mean to imply here that Zabarella was necessarily more empirical in discussing it than were his 14th-century predecessors. See, for example, Nicole Oresme, Le livre du del et du monde, text and commentary by A. D. Menut and A. J. Demony, in Mediaeval Studies III (1941), 196-198 [a new edition of this text is in preparation by Prof. Menut; and the Latin version, as yet still in manuscript, of Oresme's Quaestiones super libros de caelo et mundo is being prepared for publication by Dr. Claudia Kren of the University of Missouri]; and Joannes Buridan, Quaestiones super libris quattuor de caelo et mundo, ed. E. A. Moody (Cambridge, Mass., 1942), pp. 31-35. Zabarella certainly was aware of earlier discussions of the question, not only those of Medieval Latin authors, but those of Simphcius, Averroes, and others as well. For the general question of 'mixed bodies’ and their motion see the literature cited below in n. 58. The particular point at issue here, however—whether ‘mixed bodies’ follow the motion of their predominant element—does not seem to have been much discussed by the modern scholars.

35 Although a good deal has been written concerning the influence of technology and craftsmanship on die emergence of ‘modern science’ and ‘scientific method’ during the 16th and 17th centuries, little attempt has been made to relate this tradition to the continuing tradition of natural philosophy in the universities (e.g., see Zilsel, ‘The Sociological Roots …’, p. 550). The examples we have cited from Zabarella are by no means unique. This is a question which should be investigated further. Without a doubt Leonardo, WilHam Gilbert, and Galileo were influenced by technology, but to a significantly greater degree than those stodgy conservatives who held university chairs? See above, n. 25, for a listing of some of the relevant literature on the technological and craft traditions during the Renaissance. In emphasizing the empirical approach of Zabarella I do not in any way mean to imply that a strongly empirical approach was not also to be found in certain earlier commentators on Aristotle. A significant appeal to experience is also to be found particularly among the 14th-century natural philosophers upon whom historians of medieval science have placed so much emphasis. It is quite evident, however, that early 14th-century scholastic authors were not the only ones before Galileo to have something significant to say about experience and its function in ‘science’. Despite the enormous contributions made to our understanding of the subject by the historians of medieval science, they often appear to have an inherent prejudice against 16th-century thinkers. It sometimes seems as though for them the early 14th century is a ‘golden age’ and nothing else of significance happened until the 17th century. It will only be after a careful study of the 15th- and 16th-century writers on natural philosophy—as well as the 14th-century ones—that we shall be in a position to evaluate what progress was actually made in the later period.

36 De rebus naturalihus … , cols. 1041-1076.

37 ‘Idque etiam quotidie experimur, nam ego aliquando vidi piscem quendam quern putavi esse auratum piscem, tamen piscatores dixerunt non esse piscem auratum, sed aliam quandam speciem. Ego igitur solam convenientiam illius piscis cum aurato animadverti, differentiam autem non animadverti. Sic pueri convenientiam asini cum equo e mulo cognoscunt, sed eorum differentias non discernunt. Nos quoque adulti cognoscimus ex loco valde remoto convenientiam equi et asini et muli, differentiam vero conspicere non possumus, nisi propinquiores simus. Facilius igitur convenientia cognoscitur quam differentia.’ Ibid., De ordine intelligendi, ch. 12, col. 1065.

38 ‘Hoc autem experientia manifeste comprobatur, nam pueri primum non distinguunt equum ab asino neque a bove, sed eos omnes eodem nomine boves vocant, quia rudem illam animalis figuram et motum conspicantur videntque illud commune accidens, quod hi omnes currum trahunt; at particularia lineamenta figurae singulorum et particulares motuum conditiones nondum discernunt, hae namque differentiae continent alias, quare maiorem iudicandi vim in sensu requirunt, ut videantur.’ Ibid., col. 1067.

39 184b12-14.

40 For other examples of his use of experience to resolve philosophical disputes see the following passages in the De rebus naturalibus: col. 69 (De naturalis scientiae constitutione, ch. 24), col. 1056 (De ordine intelligendi, ch. 8), and col. 1069 (De ordine intelligendi, ch.13). I cannot quite agree with Edwards’ low estimate (The Logic of Iacopo Zabarella, p. 286) of the use which Zabarella made of experience. Although it is true that Zabarella refers to nothing more than ‘boiling tea-kettles and other very simple machines’, the fact that he refers to these is not as unimportant as it might seem. Even Galileo and the early 17th-century scientists seldom used intricate or complicated machinery in their experiments. For Galileo and the inclined plane see T. B. Settle, ‘An Experiment in the History of Science. With a Simple but Ingenious Device Galileo Could Obtain Relatively Precise Time Measurements’, Science, CXXXIII (1961), 19-23.

One of Zabarella's most striking uses ofexperientia in the context of natural philosophy is to be found in De motugravium et levium 1, 15 (ed. cit., cols. 333-338, a chapter entitled: Cur motus gravium et levium sit velocior in fine, quam in principio, plures aliorum sententiae). In a further significant passage, where Zabarella argues against Galen concerning the substance of the eye, he refers to what he has learned from observing an anatomical dissection. In De visu 11, 5 (col. 903) he says: ‘Ego igitur oculorum sectione vidi crystallinum ab aliis humoribus separatum …’, a passage pointed out to me by William F. Edwards. This is by no means a unique example of the use of information learned from anatomical dissections in arguments concerning natural philosophy and sensory psychology during the 16th and early 17th centuries. I plan to treat this topic in greater detail elsewhere.

For one example see Charles B. Schmitt, ‘Giulio Castcllani (1528-1586): A Sixteenth- Century Opponent of Scepticism’, Journal of the History of Philosophy v (1967), 15-39 a t 33-34- A further aspect of Zabarella is illuminated by Baptistae Fierae Mantuani . .. Coena notis illustrata a Carlo Avantio … (Padua, 1649), pp. 78-79. Carlo Avanzi, in his notes to the section of the work dealing with alectoriae (Cf. Pliny the Elder, Nat. hist., xxxvn, 144), says the following: ‘Ostendit etiam mihi V. CI. Jacobus Zabarella, Patavii olim Simplicium Professor, lapillos aliquot varii coloris et figurae: quos in annosi capi ventre repertos asserebat. Qui porro an fuerint in illius ventre geniti, an ab eodem cum cibo deglutiti, in re incerta non amrmaverim.’ The ‘experimental’ side of early modern Aristotelianism is well expressed by Bartholomaeus Keckermann's statement, ‘Nolo de hoc plura, nee debeo, quia experientia et sensus (optimum philosophandi principium) pro me disputat. Fac ergo experimentum, optime lector, et favebis.’ Operum omnium quae extant tomus primus (Geneva, 1614), col. 1801. This is from the treatise Contemplatio gemina: prior ex generali physka de loco, altera ex speciali de terrae motu (1601).

41 De rebus naturalibus, cols. 541-556. 42 It will be noted that the majority of the examples we cite are from the collection of opuscula on natural philosophy, entitled De rebus naturalibus libri XXX. This collection, which has hitherto been little studied, contains most of Zabarella's writings on the naturalistic works of Aristotle. He did write a commentary on the De anima, it is true, but his commentary on the Physics is fragmentary, covering only Books i, n, and vm. The latter was published only posthumously (Venice, 1601). Although Zabarella's influence as a logician has been recognized (see the works of Edwards and Petersen cited in n. 2, as well as Gilbert, Renaissance Concepts of Method, pp. 211, 213-218), the extent of his influence on the 17th-century German university teaching of natural philosophy has hardly been noticed. The theses of the period disclose that he was considered to be a major authority in natural philosophy. See, for example, Goclenius, Rodolph, Adversaria ad exotericas aliquot Julii Caesaris Scaligeri … exercitationes, 3rd ed. (Marburg, 1606); Keckermann, Bartholomaeus, Systerna physicum (Hanover, 1612); and Sagittarius, Thomas, Physicorum Aristotelico-Scaligereorum pars prior (posterior) (Leipzig, 1654).

43 Zabarella takes as his starting point Book 1 of Aristotle's Meteorology, esp. ch. 4. The key text in which the differentiation between the two regions or layers is made is at 34ibn-24.

44 Monte Venda, which is 603 meters high, is about 15 kilometers southwest of Padua.

The highest of the Colli Euganei, it has a commanding view of the surrounding area. At the present time it is the site of a meteorological observation station.

45 ‘Possumus autem etiam per experientiam id quod diximus comprobare. Mini enim contigit id quod etiam aliis pluribus contigisse audivi, ut ascenderem ad summitatem usque Montis Veneris, qui omnium in Patavino agro altissimus est, ibi per totum diem habui aerem serenissimum, sed infra circiter medium montis videbam nubes, quae me visione vallium probibebant. Vesperi autem postquam de illo monte descendi, inveni factam eo die in infera parte magnam pluviam, quum in montis cacumine nihil pluisset.

Ex eo intellexi me transisse per mediam aeris regionem in qua est facta pluvia, nee tamen earn sensi frigidissimam, imo ut vix aliquam animadverti differentiam frigidioris et calidioris aeris, nam aestivum tempus erat et pro aestivo tempore eram vertitus, nee tamen tantum frigoris quod me laederet ex eo loco percepi. Pars igitur ilia non est absolute frigida, sed solum comparatione inferi aeris calidioris.’ De regionibus aeris, ch. 8; De rebus naturalibus, col. 554. The title of this chapter is: ‘Dictae sententiae confirmatio per omnium dimcultatum solutionem et per experientiam.’ Zabarella's ‘experience’ on his trip to Monte Venda seems to have made an impression on later meteorological writers. It was directly quoted and discussed, for example, by Adriaan Heereboord, Philosophia naturalis (Nijmegen, 1665), n, 358-359 and Robert Boyle, The Works of the Honourable Robert Boyle (London, 1772), v, 695 (in the treatise General History of the Air).

46 For another excellent example of careful observation and its application to a philosophical problem by an Italian Aristotelian see my paper cited in n. 40.

47 ‘Magnum quoque veritatis testimonium praebent stillationes aquarum; videmus enim e roribus [text: rosis]in stillicidio existentibus, supposito igne vaporem elevari et in operculum stillicidii incidentem condensari et in aquam mutari; attamen si operculum illud manu tangamus, valde calidum est et quandoque ita calidum, ut manu tangentes tolerare calorem ilium nequeamus. Qui enim fieri potest, ut quum sit calidum mutet vaporem in aquam, si facere id non potest, nisi refrigerando? Dicendum igitur est operculum illud, licet calidum, frigidi tamen operam praestare respectu vaporis ascendentis calidioris ob suppositum ignem. A re igitur calida potest per condensationem aqua generari, quia, dum agit ut minus calida, agit ut frigida. Quare non est necessarium ut aer mediae regionis, si debeat vaporem in aquam mutare, sit frigidissimus, sed satis est si sit minus calidus quam inferus aer et quam vapor, qui, per inferum aerem elatus, ad mediam regionem perducitur.’ De regionibus aeris, ch. 8; De rebus naturalibus, col. 554.

48 See n. 35 above.

49 Another interesting example which indicates that Zabarella had experience outside of the lecture room is to be found in his commentary on the Posterior Analytics, where in the Latin text of the discussion he introduces a vernacular phrase to help clarify the meaning of a passage of Aristotle's Greek which is not clear in the Latin translation. See text 104 of Book 11, Opera Logica, col. 1271.

50 See especially Werner Gent, Die Philosophic des Raumes und der Zeit, second unrevised edition (Hildesheim 1962); Duhem, Pierre, Système du monde (Paris, 1913-1958), esp. vols. I and vm; Cornells de Waard, l’expérience barométrique: ses antécédents et ses explications (Thouars, 1936); and Max Jammer, Concepts of Space, 2nd ed. (New York, i960).

51 ‘Ad hoc responded solet distinguendo cognitionem: haec enim duplex est, unam vocant positivam, alteram privativam … . Privativa autem non entis cognitio est cognoscere ipsum non esse et falsam propositionem falsam esse, quam cognitionem dari non negaret Aristoteles: propterea in libris Physicorum docuit infinitum et vacuum non dari.’ In librosposteriorum analyticorum commentaria, Book 1, text 10; Opera logica col. 658.

52 ‘Cum tractatione autem de loco coniuncta esse debuit tractatio de vacuo, siquidem nil aliud significat nomen vacui quam locum sine corpore.’ Chapter 12; De rebus naturalibus, col. 34.

53 De rebus naturalibus, cols. 318-321.

54 See especially Moody, Ernest A., ‘Galileo and Avempace: The Dynamics of the Leaning Tower Experiment’,_Journal of the History of Ideas, XII 1951, 163193 375-422. To this should now be added Edward Grant, ‘Aristotle, Philoponus, Avempace, and Galileo's Pisan Dynamics’, Centaurus XI (1966), 79-95, a paper which appeared too late to be fully utilized in the present study. For an important recent attempt to integrate the whole period see Cesare Vasoli, ‘La cultura dei secoli XIV-XVI’, in Atti del primo convegno internazionale di rkognizione dellej'onti per la storia della scienza italiana: i secoli XIVXVI (Florence, 1967), 31-105.

55 ‘Averroes igitur ibi ex Aristotele sumit, necessarium esse plenum ad motum elementi propterea quod continuitas in motu a resistentia provenit, at in elemento nulla mobilis ad motorem interna resistentia est, ideo externa requiritur, si debeat fieri continuus motus; medium enim plenum resistit aliquantum elemento moto et ita facit continuitatem; quamobrem si daretur vacuum, elementum in eo positum non moveretur, sed momento temporis ad locum suum transiret, qui non esset motus, sed mutatio subita. Qua in re Averroes Avempacem reprehendit dicentem ad motum elementi non esse necessarium medium plenum, quandoquidem etiam in vacuo, si daretur, fieri elementi motus posset isque continuus ob internam resistentiam.’ De motu gravium et levium, Book 1, ch. 10; De rebus naturalibus, cols. 318-319.

56 ‘Adversus Aristotelem et Averroem hi recentiores insurgunt et aperte profitentur Aristotelem non cognovisse quae sit resistentia in motibus elementorum, imo et multa falsa dixisse in 7 Physicorum de [text: pe] proportionibus in motu. Adversus quae ipsi plura adducunt experimenta, quibus se cognovisse testantur falsas esse illas proportiones et hanc falsitatem processisse ex hoc falso fundamento, quod forma elementi movens ipsum non habet a mobili aliquam internam resistentiam, sed solum externam e medio pleno. Ipsi igitur, sequentes opinionem Avempaces ibi ab Averroe reprobatam, quam etiam sequutus est Scotus 2 sententiarum, distinctione 2, quaestione 9, dicunt duplicem esse resistentiam in motu elementi naturali: unam externam et accidentalem, quae fit a medio pleno et facit ut tardior sit motus in pleno quam esset in vacuo; alteram vero internam et essentialem, qua elementum motum resistit formae moventi, ita ut etiam in vacuo, si daretur, fieret continuus m o t u s … . Ego vero pro Aristotelis defensione possem facile demonstrare quantum isti decepti sint in illis experimentis, quae adversus Aristotelem adduxerunt, revera enim non officiunt dictis Aristotelis in 7 Physicorum de proportionibus in motu; sed quoniam alienum hoc esset a nostro instituto omittendum in praesentia e s t … sed si quando datum nobis fuerit in libros Physicos edere commentaries, diligenter hac de re loquemur.’ Ibid., col. 319. The text of Book vn of the Physics is to be found at 249b27-25oa28.

57 For an analysis of the experimental arguments in favor of a void see my paper cited in n. 28 and the works of DeWaard and Duhem cited in n. 50. The most likely candidate for Zabarella's attack, if indeed the attack is directed against a contemporary, is Bernardino Telesio. Telesio had a reputation already in Zabarella's time for being an ‘experimentalist' and we know that his discussion of the vacuum question was framed predominantly in experimental terms. See Telesio, op. cit., 1, 86-90; Cassirer, op. cit., 1, 258-260; and De Waard, op. cit., 27-28 for his views on the vacuum question. For his experimentalism in general see Antonio Persio, Liber novarum positionum (Venice, 1575), f. 3v Francis Bacon, De principiis atque originibus secundum fabulas Cupidinis et coeli: sive Parmenidis et Telesii etpraecipue Democriti philosophia tractata infabula de Cupidine, in The Works of Francis Bacon, ed. Spedding and Ellis (London, 1857-1874), III, 115; Cornelio, Tommaso, Progymnasmata physica (Venice, 1663), 118-120; R. Caverni, op. cit., 1, 435-436.

It must be noted that Telesio was born in 1509 and was therefore twenty-four years Zabarella's senior, taking his degree at Padua in 1535, when Zabarella was two years old. It is therefore difficult to see how Randall can maintain in the most recent and most permanent form of his ‘School of Padua’ article that ‘ … Zabarella went far along the path his pupil [!] Telesio was to follow’. Career of Philosophy, 1 (New York, 1962), 298. In the original version of his article (1940), Randall said, ‘Indeed, in his criticism of Platonic notions of teleology Zabarella went far along the path the radical graduate of Padua, Telesio was following’ (203). In the 1961 version, it is held that, ‘… Zabarella went far along the path the earlier pupil of the Paduans, Telesio, had already taken’ (62). This passage is omitted from still another [abbreviated] version of the article contained in Wiener, P. P. and Noland, A. (eds.), Roots of Scientific Thought (New York, 1957), 139 146 . The present writer also finds it somewhat eccentric to mention only Telesio's relation to Padua and his criticism of Platonism. First and foremost he was a critic of Aristotle, as even the most casual reading of De natura rerum discloses. Garin's judgment (cited in n. 113 below) seems more valid and more in accord with the actual evidence.

58 A discussion of this subject with Edward Grant of Indiana University and a more careful consideration of the whole context of Zabarella's treatment makes it appear that this is the more likely solution. See Grant, Edward, ‘Motion in the Void and the Principle of Inertia in the Middle Ages’, Isis LV (1964), 265-292; Idem, ‘Bradwardine and Galileo: Equality of Velocities in the Void’ Archive for the History of the Exact Sciences, II 1965, 344364 Anneliese Maier, An der Grenze von Scholastik und Naturwissenschaft, 2nd ed. (Rome, 1952), 219-254, esp. 236 ff.

59 This is in accord with the general thesis of Kuhn, Thomas S., The Structure of Scientific Revolutions (Chicago, 1962), esp. pp. 77-90.

60 See the passage cited in n. 14, esp. p. 139.

61 By this I do not imply that this distinction in itself is adequate for any detailed discussion of the problem of method as it applies to 20th-century science. I do feel, however, that it is one of the most basic distinctions which had to be made before a genuine experimental approach could evolve, and, consequently, one of the key distinctions which was emerging in the period we are here discussing. Zabarella may seem to approach the modern conception of experiment particularly with his observations on Monte Venda, but it must be noted that there is no clear evidence to indicate that he actually planned the trip to make the observations which he did. His trip might be sharply contrasted with the more famous trip to Puy-de-D6me, initiated by Blaise Pascal in 1648.

62 A good basic bibliography is to be found in A. C. Crombie, Robert Grosseteste … , 304m. To this should be added Randall, The School at Padua … ; Moody, op. cit.; Gilbert, Renaissance Concepts of Method, pp. 230-231 and passim; idem, ‘Galileo and the School of Padua’; Carlo Maccagni, ‘Esperienza tecnica e matematica nel “metodo” di Galileo Galilei’, in Actes du Symposium … (cited in n. 25), pp. 167-177; Bruno Busulini, ‘Novità metodologiche nel pensiero galileiano’, Atti della Accademia delle Scienze di Torino, classe di scienze matematiche e naturali, xcvn (1962-1963), 809-840; Namer, Émile, ‘L'intelligibilité mathématique et l'expérience chez Galilée'Revue d'histoire des sciences et leurs applications, XVII 1964, 369384 and Dubarle, Dominique, ‘La méthode scientifique de Galilée'Revue d'histoire des sciences et leurs applications, XVIII 1965, 161190 Several interesting papers have recently appeared in McMullin, Ernan (ed.), Galileo Man of Science (New York, 1967 ; but issued 1968). These include Dominique Dubarle, ‘Galileo's Methodology of Natural Science’, 295-314; Thomas B. Settle, ‘Galileo's Use of Experiment as a Tool of Investigation’, 315-337; Edward W. Strong, ‘The Relationship Between Metaphysics and Scientific Method in Galileo's Work’, 352-364; and Thomas P. McTighe, ‘Galileo's “Platonism”: a Reconsideration’, 365-387. For a more complete bibliography of recent Galileo literature see Gentili, Elio, Bibliografiagalileianafra i due centenari (1942- 1964) (Venegono Inferiore [Varese], 1966), which contains 979 items and Galileo Man of Science, i-lxxxii.

63 The date of the work seems to be 1589-1592. See Drabkin, I. E., ‘A Note on Galileo's De motu’ Isis, LI (1960), 271277 . For further information on the work see Cooper, Lane, Aristotle, Galileo and the Tower of Pisa (Ithaca, 1935), passim; Alexandre Koyré, Études galiléennes, I, 54-73; Raffaele Giacomelli, Galileo Galilei giovane e il suo ‘De motu’ (Pisa, 1949); Moody, ‘Galileo, Avempace …’; A. Koyré, ‘Le De motu gravium de Galilée: De I'expérience imaginaire et de son abus’, Revue d'histoire des sciences et leurs applications, XIII (i960), 197-245 [in this and what follows I will generally cite Koyré's articles from the original sources, although most of them are now available in the following recent collections: Études d'histoire de la pensée scientifique, ed. R. Taton (Paris, 1966) and Metaphysics and Measurement: Essays in the Scientific Revolution, ed. M. Hoskin (London, 1968)]; Busulini, Bruno, ‘Componente archimedea e componente medioevale nel De motu di Galileo'Physis, VI 1964, 303321 E. Grant, ‘Aristotle, Philoponus, …’ (cited in n. 54); Thomas B. Settle, ‘Galileo's Use of Experiment…’ (cited in n. 62); and the recent English translation Galileo Galilei, On Motion and On Mechanics, ed. I. E. Drabkin and Stillman Drake (Madison, i960), pp. 1-131. This latter work will hereafter be cited as 'Drabkin’ with an indication of page number. The critical text of the De motu will be cited from [Antonio Favaro, ed.], Le opere di Galileo Galilei (Florence, 1929-1939), 1, 243-419. Citations from the latter edition will hereafter be indicated by ‘Opere', with the volume number followed by the page number. If there is no ‘Drabkin’ reference, it will indicate that the relevant section is missing from his [partial] translation. The translations from the De motu cited in the text will be taken from Drabkin's translation where it exists, although in the view of the present writer it is not always reliable. One crucial instance where it is misleading will be discussed below. Unfortunately, this translation shows every sign of becoming accepted by historians of science as an authentic substitute for the original text. In addition to the translation being incomplete (e.g., I count nine of the thirty-eight passages cited in the present paper as being absent from the translation), it does not always convey the precise meaning of the original. Moreover, a distinguished historian of science has recently endorsed this translation with high praise in our most influential journal of the history of science. See the review of Cohen, I. Bernard in Isis LVH (1966), 501504 , which claims (502) that the translation is ‘faithful to the original which it presents’. The reviewer actually quotes (502)—apparently with a straight face and after a comparison with the original text—the very passage which I will show below to seriously misrepresent the real meaning of the Latin text.

64 A rough count gives eighteen occurrences in the 170 pages of text and two uses of the verbal form experior.

65 For example Opere 1, 252, 329, 336 (Drabkin, 14, 101, 108-109).

66 This is contained in Benedetti's Diversarum speculationum tnathematkarum et physicarum liber (Turin, 1585), 168-197. It was first printed as the preface to Benedetti's Resolutio omniumproblematum aliorumque una tantummodo circuli data apertura (Venice, 1553) and reprinted a year later as Demonstratio proportionum motuum localium contra Aristotelem (Venice, 1554). For the printing history and changes in the different editions of Benedetti's work see I. E. Drabkin, ‘Two Versions of Benedetti', G. B.s Demonstratio proportionum motuum localium’, Isis, LIV (1963), 259262 . On Benedetti and his influence see: G. Vailati, ‘Speculazioni di Giovanni Benedetti sul moto dei gravi’, in his Scritti (Leipzig- Florence, 1911), 161-178; Bordiga, G., ‘Giovanni Battista Benedetti filosofo e matematico veneziano del secolo xvi’, Atti del R. Istituto Veneto di Scienze, Lettere, ed Arti, LXXXV (1925-1926), 585754 ; Koyré, Études galiléennes, I, 41-54; idem, ‘Jean Baptiste Benedetti, critique d'Aristote’, in Mélanges qfferts à Etienne Gilson (Paris, 1959), 351-372. For further information and bibliography see the article by Cappelletti, V. in Dizionario Biografico degli Italiani, VIII (1966), 259265 , which, however, ignores the important researches of Koyré. The two following important works appeared after the present paper was essentially completed: Carlo Maccagni, Le speculazioni giovanili ‘de motu’ di Giovanni Battista Benedetti (Pisa, 1967) and idem, ‘Contributi alia biobibliografia di Giovanni Battista Benedetti’, Physis ix (1967), 337-364. The point of contact between Benedetti and Galileo is their attempt to apply the mathematical methods of Euclid and Archimedes to problems of mechanics. But, whereas Benedetti seldom refers to ‘experience’ in his work, Galileo often does in the De motu. It should be noted, however, that an admonition has recently been issued against connecting Benedetti too closely with Galileo. See Drabkin, I. E., ‘G. B. Benedetti and Galileo's De motu’, Proceedings of the Tenth International Congress of the History of Science (Paris, 1964), pp. 627630 , who points out some of the very real differences between Benedetti's writings and the De motu.

67 ‘In hunc, itaque, ordinem a natura distributa fuisse corpora, ut, scilicet, quae graviora essent, centro propinquiora manerent, continua nobis declarat experientia.’ Opere I, 344. For other examples see p . 334 (Drabkin, 107) and the Iuvenilia, in Opere 1, 68, 84, 164, 174.

68 Opere 1, 329 (Drabkin, 101).

69 ‘Non bene sibi constare videtur Aristoteles. Nam 30 Caeli t. 27, inquit: Si quod movetur neque grave neque leve fuerit, vi movebitur; et quod vi movetur, nullam gravitatis aut levitatis resistentiam habens, in infinitum movetur. Textu autem sequenti inquit, proiecta a medio ferri; cum igitur aer nee gravitatem habeat nee levitatem, a proiciente motus in infinitum movebitur, et semper eadem velocitate; ergo etiam in infinitum portabit proiecta, nee fatigabitur, cum semper eadem vi moveatur. Huius tamen contrarium experientia docet.’ Opere 1, 309 (Drabkin, 78).

70 ‘Nam de terra, quod non sit gravissima omnium, iam experientia docet: ipsa enim metallis liquatis omnibus supernatat, ut argento quod dicunt vivo; ex quo patet, metalla graviora esse ipsa terra.’ Opere I, 360.

71 Other examples are: ‘at contrarium accidere experientia docet.’ Opere I, 330 (Drabkin, 102); ‘experientia tamen contrarium ostendit’. Opere I, 334 (Drabkin, 107); ‘experientia tamen contrarium ostendi’. Opere I, 356; ‘contrarium etiam experientia docet’. Opere 1, 370; ‘cuius tamen contrarium experientia demonstrat’. Opere 1, 371; ‘et licet experientia contrarium potius interdum ostendat’. Opere 1, 406; and in the Iuuenilia, in Opere 1, 49(2), 58, 130.

72 ‘Aristoteles igitur, 4Phys. t. 71, scripsit, idem mobile citius moveri in medio subtiliori quam in crassiori, et, ideo, tarditatis motus causam esse crassitiem medii, velocitatis autem subtilitas; et hoc non alia ratione confirmavit nisi ab experientia, quia, nempe, videmus mobile aliquod velocius moveri in aere quam in aqua. Verum hanc causam non sufficientem esse, proclive erit demonstrare.’ Opere 1, 260 (Drabkin, 24).

73 ‘Manifestum est igitur, insumcienter ab Aristotele dictum fuisse, tarditatem motus naturalis ob medii crassitiem contingere. Quapropter, ipsius opinione derelicta, ut veram tarditatis et celeritatis motus causam afferamus, attendendum est, celeritatem non distingui a motu.’ Opere I, 261 (Drabkin, 24-25).

74 ‘Sed, ut semper rationibus magis quam exemplis utamur (quaerimus enim effectuum causas, quae ab experientia non traduntur), sententiam nostram in medium afferemus, ex cuius comprobatione corruet Aristotelis opinio’. Opere 1, 263 (Drabkin, 27).

75 See the text cited in n. 69.

76 Already in the De motu Galileo expresses enormous admiration for Archimedes: 'suprahumani Archimedis’, Opere 1, 300 (Drabkin, 67); ‘divino Archimede’, Opere 1, 303 (Drabkin, 71); ‘divinissimi Archimidis’, Opere I, 368. Koyré most strongly emphasized the Archimedean element in Galileo: see especially his Études galiléennes 1, 72-73, but also Gilbert, ‘Galileo and the School of Padua’, 231; Busulini, ‘Componente archimedea e componente medioevale … ‘ ; Garin, Eugenio, ‘Gli umanisti e la scienza'Rivista di Filosofia, LII 1961, 259278 esp. 268, 277-278; and Marshall Clagett, Archimedes in the Middle Ages, 1: ‘The Arabo-Latin Tradition’ (Madison, 1964), 1.

77 ‘Aristotelem parum in geometria fuisse versatum, multis in locis suae philosophiae apparet; sed in hoc potissimum, ubi asserit, motum circularem motui recto non esse proportionatum, quia, scilicet, recta linea curvae non est proportionata aut comparabilis: quod quidem mendacium (indignum enim est nomine opinionis), nedum intima et magis recondita geometriae inventa, Aristotelem ignorasse, verum et minima etiam principia huius scientiae, demonstrat.’ Opere 1, 302 (Drabkin, 70). However, see below n. 79.

78 ‘Methodus quam in hoc tractatu servabimus ea erit, ut semper dicenda ex dictis pendeant; nee unquam (si licebit) declaranda supponam tanquam vera. Quam quidem methodum mathematici mei me docuere; nee satis quidem a philosophis quibusdam servatur, qui saepius, physica elementa docentes, ea quae seu in libris De anima, seu in libris De caelo, quin et in Metaphysicis, tradita, supponunt; nee etiam hoc sufticit, sed etiam, docentes logicam ipsam, continue ea in ore habent quae in ultimis Aristotelis libris tradita sunt; ita ut, dum discipulos prima docent, supponunt eos omnia scire, doctrinamque tradunt non ex notioribus, verum ex ignotis simpliciter et inauditis. Accidit autem ita addiscentibus, ut nunquam quicquam per causas sciant, sed tantum ut fide credant, quia, nempe, hoc dixerit Aristoteles. Utrum deinde verum sit quod dixerit Aristoteles, pauci sunt qui quaerant: sufficit enim his, quod eo doctiores habebuntur, quo plures Aristotelis locos prae manibus habebunt.’ Opere I, 285 (Drabkin, 50-51). It is not at all clear that the phrase mathematici mei should be translated as ‘my teachers of mathematics’. Such a meaning is certainly possible, but it can as easily mean—more easily on the basis of the text we have—'my mathematicians’, meaning the authors (primarily Greek) on mathematics whom Galileo had studied and admired. This is the way in which it is interpreted by Grimaldi, Vincenzo, La mente di Galileo Galilei desunta principalmente dal libro De motu gravium (Naples, 1901), p. 118 , a work which otherwise is of little value for an understanding of the De motu.

79 The basic approach of the Posterior Analytics, as well as many of the examples which Aristotle uses in the work, is strongly geometrical, reflecting Greek geometrical tradition a few decades before Euclid. See Lee, H. D. P., ‘Geometrical Method and Aristotle's Account of First Principles’Classical Quarterly, XXIX 1935, 113124

80 Here the whole approach seems to be more matter of probability, less geometrical, and more a product of experience. See McCue, James F., ‘Scientific Procedure in Aristotle's De coelo’, Traditio XVIII (1962), 124 .

81 See Opere 1, 277-278 (Drabkin, 42), where he denounces one of Aristotle's supposed 'demonstrations’ for being based upon axioms (axiomata) which are neither obvious (manifesto) to the senses, nor demonstrated, nor demonstrable.

82 ‘Verum, caeterorum omissis sententiis, ut veram, quam credimus, huius effectus causam indagemus, hac resolutiva methodo utemur’. Opere I, 318 (Drabkin, 88).

83 ‘Verum magis resistit quod contra nititur, quam quod aut quiescit aut ad eadem fertur: in eo, ergo, quod contra nititur, arctius virtus imprimitur; quod experientia docti qui follibus ludunt, ab aliquo contra se follem deici volunt, ut in eo reluctante et magis resistente plus virtutis motivae imprimatur. Verum, ut iam diximus, id soli praestare possunt, qui robusto fortique brachio praediti sunt: qui vero languidi sunt viribus, nee contra impetum niti possunt, contra quiescentem vel non ad contrarias tendentem follem moventur; quod si ad easdem moveatur follis, paululum, ut quisque novit, impellitur. Cuius effectus causa quidem est, quia quod quiescit, a maxima virtute percussum, movetur antequam tota virtus imprimatur, cum illius mobilitas impressionem tantae virtutis non expectet: quod non accidit in eo quod in contrarias [sic] cietur; nam, aucta per motum suae gravitatis resistentia, magis resistit, nee ante totius virtutis impressionem retrocedit. Et hoc idem experimur omnes, cum lapidem ante proicere volumus.’ Opere 1, 338 (Drabkin, III ) . See also Opere 1, 264 (Drabkin, 28).

84 See for example, the text of John Buridan cited from his Quaestiones super libris quattuor de caelo et mundo in Clagett, Marshall, The Science of Mechanics in the Middle Ages (Madison, 1959), p. 524 , n. 39 and Cardano, Girolamo, Opera Omnia (Lyon, 1663), 1 , 360 (2 examples).

85 For a clear example of periculum used to mean ‘experiment’ see Cicero's In Pisonem xxvii, 65 (Fac huius odii tanti ac tarn universi periculum, si audes). This text is translated by a recent editor as follows: ‘Test by experiment this bitter and widespread hatred, if you dare.’ Cicero, The Speeches, ed. N. H. Watts (London: Loeb Library, 1931), p. 219. The same translation is suggested by R. G. M. Nisbet in his edition of the work (Oxford, 1961), p. 128. In Plautus’ Asinaria, in, 3, one of the characters in speaking of love says: 'Scio qui periculum feci’, i.e., ‘I, who have tried it, know’. Other examples are to be found in Lewis and Short's Dictionary and Mario Nizoli's Lexicon Ciceronianum.

86 The only example I have been able to find is in Giordano Bruno's De gli eroicifurori V: ‘la quale finalmente non tanto per far pericolo di sua gloria’, in Dialoghi Italiani, ed. Gentile-Aquilecchia (Florence, 1958), 1173, where the editor correctly explains it in a note. In my opinion, the recent English translation [Giordano Bruno's The Heroic Frenzies, trans. Paul Eugene Memmo, Jr. (Chapel Hill, 1964), 263] miscontrues this passage. The Vocabulario degli Accademici della Crusca (Florence, 1691) gives no instance which approximates the way in which Bruno uses it, nor do any of the other Italian dictionaries which I have been able to consult. It is interesting to note, however, that the Vocabulario gives as Latin equivalents for cimento (n, 336) the following: ‘periculum, experimentum, tentamentum’. Although I have not investigated this in detail, it is obvious that esperienza, sperimento, and sperimentore are commonly used in Galileo's later Italian works. These also became the standard words in the Galileian tradition of the 17th century in Italy. See, for example, the material in Le opere dei discepoli di Galileo Galilei, I (L'Accademia del Cimento) (Florence, 1942). In the Latin translation of these experiments, which gained European distribution, experimentum is used to translate esperienza. See Tentamina experimentorum naturalium captorum in Academia del Cimento … Ex italico in latinum sermonem conversa. Quibus commentarios, nova experimenta, et orationem de methodo instituendi experimenta physica addidit Petrus van Musschenbroek (Leiden, 1731). See nn. 102 and 131 below.

87 This is true, both in the examples referred to above in n. 85 and in all of those which I have found in the De motu. It should be noted here, however, that this does not necessarily imply that periculum refers to an actual physical experiment. The De motu is still open to the same general problems—as are the remainder of Galileo's works—of distinguishing 'physical experiments’ from ‘thought experiments’. The question of the role of 'thought experiments’ in the De motu—as well as the more general problem of their changing function as Galileo developed from youth to maturity and old age—is a very important one which should be dealt with in detail. It would take us too far afield, however, to treat the matter exhaustively here.

88 ‘Nisi forte credas, probationem esse id quod t. 39 eiusdem libri ponit, dicens, ignem non descensurum, quia nullam habet gravitatem: sed hoc esset probare idem per idem, si, dum conatur demonstrare, ignem nullam habere gravitatem eo quod non descendit, probaret ipsum non descendere quia nullam habeat gravitatem. Eget itaque hoc demonstratione; et eo amplius, quia nee ipse Aristoteles, quod credam, periculum fecit, an descendat ignis remoto aere. Quod autem non sit aliquid igne levius, unde scivit Aristoteles? Nonne possunt esse exhalationes aliquae, quae super ignem advolent? Sed, demum, quomodo unquam poterit quis ignem imaginari, substantiam cum quantitate coniunctam, gravitatem non habere? Hoc profecto omnino mihi irrationabile videtur.’ Opere 1, 377. The text referred to is found in De coelo, 312b3-20.

89 See Koyré, ‘Le De motu gravium . . .’, pp. 211-212. We should note, however, the following interesting passage which deals with the determination of precise weights and which is couched in wholly theoretical terms: ‘Quod si in vacuo ponderari possent, tunc certe, ubi nulla medii gravitas ponderum gravitatem minueret, eorum exactas perciperemus gravitates.’ Opere 1, 276 (Drabkin, 40). On Galileo's position regarding the void problem see especially his correspondence with Giovanni Battista Baliani and De Waard, op. cit., 93-101.

90 ‘Hae, igitur, universales sunt regulae proportionum motuum mobilium, sive eiusdem sive non eiusdem speciei, in eodem vel in diversis mediis, sursum aut deorsum motorum.

Sed animadvertendum est, quod magna hie oritur difficultas: quod proportiones istae, ab eo qui periculum fecerit, non observari comperientur. Si enim duo diversa mobilia accipiet, quae tales habeant conditiones ut alterum altero duplo citius feratur, et ex turri deinde demittat, non certe velocius, duplo citius, terram pertinget.’ Opere I, 273 (Drabkin, 37-38). Cf. Koyré, ‘Le De motu . . .’, p. 227.

91 The wording seems to indicate that again we have a ‘thought experiment’ rather than an actual physical one.

92 See Opere 1, 333-337 (Drabkin, 106-110).

93 ‘Quae quidem diversitates et, quodammodo, prodigia unde accidant (per accidens enim haec sunt), non est hie locus inquirendi’. Opere 1, 273 (Drabkin, 38).

94 ‘Experientia tamen contrarium ostendit: verum enim est, lignum in principio sui motus ocius ferri plumbo; attamen paulo post adeo accelerator motus plumbi, ut lignum post se relinquat, et, si ex alta turri demittantur, per magnum spatium praecedat: et de hoc saepe periculum feci. Firmiorem igitur causam ex firmioribus hypothesibus ut hauriamus, tentandum est’. Opere I, 334 (Drabkin, 107).

95 The bulk of the evidence seems to indicate that he did not. See the material cited in n. 123. Thomas B. Settle, ‘Galileo's Use of Experiment…’ interprets the evidence of the De motu in a way almost completely contrary to that of the present article. Professor Settle sees the De motu as being based almost completely on experimental evidence, and, indeed, believes that Galileo's ‘experimentalism’ was already very much in evidence during the Pisa period. In reading his article after the present study had been completed, I have found that he presents no new and compelling evidence to make me change my interpretation. I have had many fruitful conversations with Professor Settle over the past several years, which have helped to elucidate many points regarding Galileo and early modern science, but I fear that we are in fundamental disagreement on several crucial points, including the following: (1) In how far are Galileo's claims to have utilized experientiae to be accepted at face value; (2) How much credence is to be given to the testimony of Viviani; and (3) How far is the possibility for Galileo to perform a given experiment to be taken as evidence that he actually did perform it?

On the problem of actually performing an ‘experiment’ to discredit the Aristotelian position see Toulmin, S. and Goodfield, J., The Fabric of the Heavens (London, 1961, cited from Penguin ed., London, 1963), pp. 108-109. Galileo's statement that ‘wood moves more swiftly than lead at the beginning’, but that lead later passes it, is somewhat baffling. See Settle, art cit., 325-326, who is also puzzled by this text, but who analyzes it very perceptively. Dr. Donald R. Miklich of the Children's Asthma Research Institute and Hospital in Denver has recently made a most valuable suggestion (in a private communication). Dr. Miklich argues that if one attempted the experiment of dropping a lead and a wooden ball simultaneously—especially if he had been holding the two for some time to line diem up accurately, for example—, then the muscular fatigue would be greater in the hand holding the heavier object. This would result in his being unable to release the lead ball as quickly as the wooden one and, consequently, he would see the wooden ball move ahead of the lead one. It may well be that Galileo and others (e.g. Girolamo Borri, as Settle, 325-326 suggests) tried this experiment with the result described. If such is the case, it must be noted that Galileo states that after the wood is initially ahead, ‘a little later the motion of the lead is so accelerated that it leaves the wood behind.’ One can now raise the question of whether Galileo actually observed such a thing to happen. It seems highly unlikely that he did, for it is difficult to imagine under what circumstances it would actually happen that the lead would pass the wood. The inescapable conclusion is that, if Galileo, for the reason suggested by Dr. Miklich, saw the wooden ball move ahead of the lead one, his further statement of the lead ball passing the wooden one at a later stage was based wholly on theoretical considerations, rather than experimental or observational ones. That is, although Galileo saw the lighter object move ahead of the heavier, he knew on the basis of his fundamental hypothesis concerning the nature of light and heavy bodies that the lead ball would overtake the wooden one. Here again attempted experiment is subverted by a priori theory. Call it Platonic if you like or give it anodier name, but the conclusion seems unmistakable.

96 ‘Et haec quae demonstravimus, ut etiam supra diximus, intelligenda sunt de mobilibus ab omni extrinseca resistentia immunibus: quae quidem cum forte impossibile sit in materia invenire, ne miretur aliquis, de his periculum faciens, si experientia frustretur, et magna sphaera, etiam si in piano horizontali, minima vi non possit moveri’. Opere I, 300-301 (Drabkin, 68). That the demonstrations involve an idealized situation is again reiterated shortly afterwards: ‘Sed, ut saepius diximus, hae demonstrationes supponunt, nulla esse extrinseca impedimenta, seu mobilis figurae, seu plani aut mobilis asperitatis, seu medii in contrarias aut in easdem partes moti, seu extrinseci motoris virtutis urgentis aut retardantis motum, et similia: de his enim accidentibus, eo quod innumeris modis accidere possint, regulae tradi nequeunt’. Opere 1, 302 (Drabkin, 69). Cf. Koyré, Études galiléennes, 1, 72-73.

97 The meaning of forte may be better expressed in this context as ‘accidentally’ or 'through no fault of ours’.

98 I.e., in the physical world of nature.

99 Or ‘should not wonder’.

100 I.e., the result of the experiment, which the experimenter observes or ‘takes in’ as an experience deriving from the planned periculum which he has performed.

101 I.e., it fails to turn out as one might have predicted or fails to produce the soughtafter result.

102 See the text cited in n. 94. Although Galileo's use of periculum is somewhat unusual in such passages it is by no means unique. One example of its use during the period is to be found in Iossius, Nicander, Tractatus novus utilis et iucundus de voluptate et dolore, somno et vigilia, deque fame et siti (Frankfurt, 1603), pp. 5051 , in a work first printed at Rome in 1580. Here we read in the section, De voluptate et dolore opusculum: ‘Quid turn de continuitatis solutione, potest ne aliquis dubitare ne ab ilia etiam fiant insignes dolores? cum illud pateat experimento, videmus enim sive per incisionem aut puncturam, erosionem vel contusionem, aliove quovis modo fiat haud mediocres, sed pene intolerabiles fieri dolores, quorum nemo est, ut arbitror, qui in se ipso periculum non fecerit, ratio vero ilia, quoniam soluens continuam realem passionem inurit sensitivo corpori gravemque laesionem corrumpentem partis naturam, quippe quae sua natura est una.’

A more significant example occurs in Sanctorius Sanctorius, De statica medirina (Leipzig, 1670), f. A4v, in the Prefatory Letter to the Reader, which begins: ‘Novum atque inauditum est in medicina posse quempiam ad exactam perspirationis insensibilis ponderationem pervenire; nee quisquam philosophorum, nee medicorum unquam hanc medicae facultatis particulam aggredi ausus est. Ego vero primus periculum feci et (nisi me fallat genius) artem ratione et triginta annorum experientia ad perfectionem deduxi, quam consultius judicavi doctrina aphoristica, quam diexodica describere. Primo ad imitationem magni nostri dictatoris, cujus vestigiis insistere gloriosum semper duxi; deinde id feci, quasi necessitate impulsus quandoquidem ipsa experimenta, quibus quotidie assiduis multorum annorum studiis incumbebam … .’ Here, it is interesting to note, experientia, experimentum, and periculum are all used in the same passage. This should be studied with greater care, but it would take us too far afield to do so here. On Santorio, who studied medicine and philosophy (with Zabarella!) at Padua from 1575 to 1582 and took a medical degree in the latter year, see especially A. Castiglioni, La vita e Vopera di Santorio Santorio capodistriano (1561-1636) (Bologna, 1920: authorized English trans, by Emilie Recht in Medical Life, n.s. 135 [New York: December, 1931], 727-786) and Grmek, Mirko Drazen, Santorio Santorio i njegovi aparati i instrumenti (Zagreb, 1952), with English summary, 79-82.

The fact that both of these examples are found in medical writings may suggest that the term was commonly used by medical authors of the late 16th and early 17th centuries. In Galileo's case it may be a carry-over from his early medical studies. This point must be investigated further elsewhere. See also below, n. 131.

103 ‘His responderem, me sub suprahumani Archimedis (quern nunquam absque admiratione nomino) alis memet protegere’. Opere I, 300 (Drabkin, 67).

104 Ibid. Cf. Koyré, Études galiéennes, I, 72.

105 ‘At quia, ex tribus mediis per quae fiunt motus, ignis a nobis nimium distat, cumque in aere non nisi de motu deorsum periculum facere possimus; ea enim, quae apud nos sunt, omnia aere sunt graviora; ideo in medio aquae demonstrationes nostrae verificabuntur: habemus enim corpora nonnulla quae in aqua descendunt, et item aliqua quae, in aquam demissa, sursum petunt. Attamen [etiam cancelled] ea quae de aqua ostendentur et de mobilibus in ea, vera sunt quoque de aliis duobus mediis, aeris nempe, et ignis. Demonstrationibus autem quas [ms.: quae] afferam, similes demonstratae sunt ab Archimede; attamen aliis suppositis, aliis mediis in demonstrationibus adsumptis. Quae omnia cum sint pure mathematica [ms.: matematka], a me rationibus quibusdam magis physicis demonstrabuntur; eo quod magis conferent ad praesens negocium.’ Opere 1, 380m.

106 See especially Koyré, ‘Le De motum gravium de Galilée …’, ed. cit.

107 Galileo draws a clear distinction between ‘mathematical’ and ‘physical’explanation: Of ere 1,257 (Drabkin, 20). Even what he calls a'physical’ approach is not an experimental one, but primarily a theoretical discussion which deals with physical entities, as we see from the section of his work which follows, i.e., where he is specifically approaching the subject physice.

108 There has been a conjoining of mathematical with philosophical interests upon rare occasions among the Aristotehans, primarily with some of the 14th-century French and English natural philosophers. A rare Italian example is Blasius of Parma. The general situation becomes most apparent when one considers how few of the 15th- and 16thcentury commentators and translators, who concerned themselves with ancient mathematical works, were Aristotelians.

109 The differences between Galileo's ‘Platonism’ and other varieties of Platonism are shown by Ernst Cassirer, ‘Galileo's Platonism’, in Montague, M. F. Ashley, ed., Studies and Essays in the History of Science and Learning Offered in Homage to George Sarton on the Occasion of his Sixtieth Birthday (New York, 1944), 279297 . Cf. Garin, Scienza e vita civile net Rinascimento (Bari, 1965), p. 157. There has been a good deal of discussion recently on the point of Galileo's ‘Platonism’. See especially the papers of McTighe and Strong cited above in n. 62 and Cassirer's ‘Mathematical Mysticism and Mathematical Science’, trans, by E. McMullin for Galileo Man of Science, 338-351 [originally in Lychnos V (1940), 248-265, as ‘Mathematische Mystik und Naturwissenschaft’]. Both McTighe and Strong argue against calling Galileo a ‘Platonist’. The argument is largely sterile at this point. What is evident is that Galileo did accept certain positions identified more closely with the Platonic tradition (broadly conceived) than with any other major philosophical tradition, but he quite obviously did not accept all tenets of all Platonists. I have not yet been able to see M. Clavelin, La philosophie naturelle de Galilée (Paris, 1968). According to the publisher's advertisement the conclusion of this book is optimistically 'Finalement l'idée d'un Galilée platonicien apparait pour ce qu'elle est: un mythe.’ 110 See the works of Randall and Edwards cited above.

111 The case with Zabarella seems to have been essentially the same as Professor R. W. Southern has pointed out that it was with Grosseteste and Roger Bacon. See Crombie, A. C., ed., Scientific Change (London, 1963), pp. 301306 , esp. 304.

112 See below for a fuller discussion of this.

113 Eugenio Garin, Scienza e vita civile nel Rinascimento italiano (Ban, 1965), p . 179 observes: 'La filosofia della natura di Telesio non conquistò gli Studi [di Padova], come non vi penetrò nessuna delle posizioni veramente dinamiche del Cinquecento. Nè la situazione di Padova, con buona pace di certi storici, era diversa de quella di Pisa.’ See my review of this important book in International Philosophical Quarterly VIII (1968), 297-303.

114 Vincenzo Viviani wrote in his Racconto (Opere, xix, 602): ‘Udì i precetti della logica da un Padre Valombrosano; ma però que'termini dialettici, le tante definizioni e distinzioni, la moltiplicità delli scritti, Fordine et il progresso della doctrina, tutto riusciva tedioso, di poco frutto e di minor satisfazione al suo esquisito intelletto.’ This must be read with the same caution as other sections of Viviani's work (see below n. 123), but there are passages in Galileo's writings from all periods of his life which clearly state his dislike of Aristotelian logic. For the polemic between Zabarella and Piccolomini and Petrella see Pietro Ragnisco, ‘La polemica tra Francesco Piccolomini e Giacomo Zabarella nella Università di Padova’, Atti delR. Instituto Veneto, ser. VI, IV (1885-1886), 1119-1252, and idem, ‘Una polemica di logica nell Universita di Padova nelle scuole di Bernardino Petrella e di Giacomo Zabarella’, ibid., ser. vi, IV, 463-502.

115 The present writer plans to discuss this topic more fully in a paper on Galileo's use of models and analogies in the De motu.

116 This is quite apparent, for example, in Opere I, 254-257 (Drabkin, 17-20). Galileo's approach here is certainly less formal than that which we find in Archimedes’ On Floating Bodies, but it must be remembered that the De motu does not have the character of a completed work; it is rather more in the nature of a preliminary draft.

117 Printed in Opere I, 9-177. The precise significance of these notes has not yet been determined. Most Galileo scholars are of the opinion that they do not represent his original thought, but are merely his professors’ (especially Bonamici's) teachings which he copied down. It is possible, however, that they with the logic Quaestiones might represent an early Aristotelian phase against which he later reacted violently, e.g., in works such as the De motu, as Giacomelli, op. cit., 6-12, seems to suggest.

118 See Opere ix, 279-282, 291-292 for a discussion of these Quaestiones, a listing of the topics treated, and a sample question. These were excluded from the National Edition of the Opere. It is hoped that a complete edition of them will be forthcoming shortly. It is essential to study this material with greater care if we are to have a clearer understanding of Galileo's methodological sources. It is presently MS. Galileo 27 of the Biblioteca Nazionale of Florence. For descriptions see, in addition to the pages in the Opere, cited above, A. Procissi, La collezione galileiana della Biblioteca Nazionale di Firenze, 1 (Rome, 1959). 106-107. Among the authors whom Galileo cites in the Quaestiones are: Themistius, Philoponus, Algazel, Avicenna, Averroes, Thomas Aquinas, Albertus Magnus, Caietanus, Zimara, and Balduinus. The mentioning of the last three (e.g., f. 29v) indicates that Galileo had at least some acquaintance with important Italian Aristotelian thinkers from Padua, even during his Pisan period. The importance of this manuscript becomes even more crucial for the resolution of the problem of the relation of Galileo to the Aristotelian movement, when we note that the Tertia disputatio (fs. 29r-31v) is entided ‘De speciebus demonstrationis’ and that the Quaestio tertia of this has the title of ‘An detur regressus demonstrativus’ (fs. 31r-31v ) . It is unfortunate that Favaro omitted this material from his edition, but since he has done so, we must not fall into the trap of following his judgment as to its ‘unimportance’, as Gilbert seems to have done. See his ‘Galileo and the School of Padua’, p. 224.

119 These include: La bilancetta ﹛Opere 1, 211-220) of 1586, the first extant work in Italian and one which shows its dependence upon Archimedes even from the opening sentence; a list oiesperienze carried out with the balance ﹛Opere 1, 223-228); the Theoremata circa centrumgravitatis solidorum ﹛Opere 1, 181-208) of 1587, also clearly under Archimedean influence; and some annotations on Archimedes’ De sphera et cylindro of about the same time ﹛Opere 1, 231-242).

In addition to these works of scientific and mathematical interest from the pre-Padua period, we have also several works of primarily literary orientation. These include Due lezioni all'accademiafiorentina circa lafigura, sito e grandezza dell'inferno di Dante ﹛Opere ix, 31-57) and his satirical poem, Capitolo contro ilportar la toga ﹛Opere ix, 213-223). In the first of these Galileo attempts to determine certain physical characteristics of Dante's Inferno, but rather than basing his estimates on observation and experience, he realizes that a different approach is necessary: ‘Se è stata cosa difficile e mirabile … l'aver potuto gli uomini per lunghe osservazioni, con vigilie continue, con perigliose navigazioni, misurare e determinare gFintervalh de i cieli, i moti veloci ed i tardi e le loro proporzioni. .. quanto phù maravigliosa deviamo noi stimare l'investigazione e descrizione del sito e figura dell'Inferno, il quale, sepolto nelle viscere della terra, nascoso a tutti i sensi, è da nessuno per niuna esperienza conosciuto …’ (p. 31). The method to be used again turns out to be that of Archimedes: ‘Ma volendo sapere la sua grandeza rispetto a tutto l'aggregato dell'aqqua [sic] e della terra, non doviamo già seguitare la opinione di alcuno che dell'Inferno abbia scritto, stimandolo occupare la sesta parte dello aggregato; però che facendone il conto secondo le cose dimostrate da Archimede ne i libri Delia sfera e del cilindro, troveremo che il vano dell'Inferno occupa qualcosa meno di una delle 14 parti di tutto l'aggregato’ (p. 34). The whole approach to this problem is mathematical and one might observe that, not only is ‘the book of nature’ written in mathematical terms, but, in this case at least, the ‘book of the supernatural’ is as well. Whereas we might ex pect the analysis to contain some elements of the technology and craftsmanship so vividly and graphically portrayed by Dante himself in the description of the inferno, they are wholly absent. Rather, the point of departure, besides Archimedes, is from Euclid's Elements: '… se tale Inferno fosse una intera sfera, sarebbe una delle mille parti di tutto l'aggregato, come da gli Elementi d'Euclide facilmente si cava’ (p. 48).

Although his poem, strictly speaking, contains nothing to allow us to decide whether Galileo was, at that time, experimentally or mathematically oriented, one might draw a certain significance from the following passage, jocose as it may be:

'Perchè, secondo l'opinion mia,

A chi vuol una cosa ritrovare,

Bisogna adoperar la fantasia,

E giocar d'invenzione, e ‘ndovinare;

E se tu non puoi ire a dirittura,

Mill'altre vie ti posson aiutare

Questo par che c’ insegni la natura,

Che quand'un non può ir per l'ordinario,

Va dret’ a una strada phù sicura.’ (pp. 213-214)

For further information on the purely literary aspects of Galileo's works and his influence on Italian literary style see especially Enrico Falqui, ‘Galileo Galilei e la prosa scientifica del Seicento’, in Letteratura italiana: I minori, 1 (Milan, 1961), 1523-1572, where further bibliography will be found. For a valuable summary of Galileo's Florentine background —literary and intellectual—see Eric Cochrane, ‘The Florentine Background of Galileo's Work’, in Galileo Man of Science, pp. 118-139.

120 Opere x , 22-50. This includes correspondence with Christophorus Clavius (2 letters by Galileo, 2 by Clavius), Guidobaldo dal Monte (one by Galileo, 12 by Guidobaldo), and one letter in Latin to Galileo from Michael Coignet, a mathematician at Antwerp.

121 Opere 1, 219-220. The description here is quite detailed, even going into how to overcome some of the practical difficulties which may be encountered in constructing a balance. One does not find any such practical hints in the writings of Archimedes which have come down to us. The Pseudo-Archimedean work, De insidentibus in humidum, however, gives a number of practical details, as do other medieval treatises on weights. See Moody, Ernest A. and Clagett, Marshall, eds., The Medieval Science of Weights (Madison, 1952), pp. 4053 , esp. definitio 1, p. 40. As Moody points out in his introduction (p.39) this work was printed in the 16th century, but was not attributed to Archimedes except in a French translation of 1565. Blasius of Parma's Tractatus de ponderibus (Moody and Clagett, ed. cit., pp. 229-279) gives numerous practical details, e.g., p. 275.

122 ‘Cominciò questi [i.e., Galileo] ne’ prim'anni della sua fanciullezza a dar saggio della vivacità del suo ingegno, poichè nell'ore di spasso esercitavasi per lo piu in fabbricarsi di propria mano varii strumenti e machinette, con imitare e porre in piccol modello ci6 che vedeva d'artifizioso, come di molini, galere, et anco d'ogni altra macchina ben volgare. In difetto di qualche parte necessaria ad alcuno de’ suoi fanciulleschi artifizii suppliva con Finvenzione, servendosi di stecche di belena in vece di molli di ferro, o d'altro in altra parte, secondo gli suggeriva il bisogno, adattando alia macchina nuovi pensieri e scherzi di moti, purchè non restasse imperfetta e che vedesse operarla.’ Opere xix, 601. Gherardini's Vita (Opere xix, 633-646), however, strongly emphasizes Galileo's great love for mathematics during the time he was at Pisa (pp. 636-637).

123 Opere XIX, 603, 606. For a summary of the problems see Giacomelli, op. cit., 6-12. See also Lane Cooper, op. cit.; Favaro, Antonio, ‘Sulla veridicita del “Racconto istorico della Vita di Galileo” ‘, Archivio storico italiano, LXXIII (1915), 323380 ; idem, ‘Di alcune inesattczze nel “Racconto istorico della Vita di Galileo” ‘ibid., LXXIV 1916, 127-150

124 Opere x, 55-57. After a long involved discussion, Galileo says: ‘… et tutto questo e manifestissimo per l'esperienza’ (p. 57). A further avenue of exploration with regard to Galileo's dependence upon experience, and one which remains largely unstudied, is the empirical musical background of his father Vincenzo Galilei. Careful study could perhaps elucidate whether Galileo was influenced by Vincenzo's attitude toward music. Much important material is collected by Claude V. Palisca, ‘Scientific Empiricism in Musical Thought’, in Rhys, H. H., ed., Seventeenth Century Science and the Arts (Princeton, 1961), pp. 91137 . See also Olschki, op. cit., III, 135-139. Dr. J. R. Ravetz has called this material to my attention; his incisive criticisms of an earlier draft of this paper have added immeasurably to its improvement.

125 Opere n, 7-146.

126 Opere 11, 155. T h e treatise opens as follows: ‘Degno di grandissima considcrazione mi è parso, avanti che discendiamo alia speculazione delli strumenti mecanici, il considerare in universale, e di mettere quasi inanzi agli occhi, quali siano i commodi, che dai medesimi strumenti si ritraggono: e cio h o giudicato tanto piu doversi fare, quanto (se non m'inganno) più ho visto ingannarsi l'universale dei mecanici … perchè, quando niuno utile fusse da sperarne [i.e., of the science of mechanics], vana saria ogni fatica che nell'acquisto suo s'impiegasse’ (pp. 155-156).

127 In his article Galilei, Galileo’, Encyclopedia of Philosophy (New York, 1967), III, 262-267, at 265b. The work is printed in Opere rv, 5-141.

128 ‘E perchè la dottrina che io séguito nel proposito di che si tratta è diversa da quella d'Aristotile e da’ suoi principii, ho considerate) che contro l'autorità di quell'uomo grandissimo, la quale appresso di molti mette in sospetto di falso ciò che non esce dalle scuole peripatetiche, si possa molto meglio dir sua ragione con la penna che con la lingua, e per cio mi son risoluto scriverne il presente discorso: nel quale spero ancor di mostrare che, per capriccio, o per non aver letto o inteso Aristotile, alcuna volta mi parto dall'opinion sua, ma perchè le ragioni me lo persuadono, e lo stesso Aristotile mi ha insegnato quietar l'intelletto a quello che m'e persuaso dalla ragione, e non dalla sola autorità del maestro …’, Opere IV, 65. Cf. pp. 80-86 where there is an extended refutation of positions advanced in Bonamici's De motu.

129 E.g., ibid., p. 67.

130 ‘… e sara l'una e l'altra esperienza molto ben Concorde alia dottrina d'Archimede …’, ibid., p . 82; ‘… potremo con sicurezza dire, la dottrina d'Archimede esser vera, poichè acconciamente ella s'adatta alle esperienze vere …’, ibid., p. 83.

131 ‘Ma perchè tali cose, profferite cosi in astratto, hanno qualche difficultà all'esser comprese, è bene che vegniamo a dimostrarle con esempli particulari: e, per agevolezza della dimostrazione, intenderemo, i vasi, ne'quali s'abbia ad infonder l'acqua …’, ibid., p. 7 1 ; ‘ … qualunque volta noi vogliamo far prova di ciò che operi circa questo effetto la diversità della figura, sara necessario far l'esperienza con materie nelle quali la varietà delle gravezze non abbia luogo … ‘ , ibid., p. 88. The second passage cited above is interesting in so far as it seems to distinguish between far prova and/ar l'esperienza, something we cannot discuss in detail here. For the present context, however, it is perhaps of interest to note thatfacere periculum may be the Latin usage behind the former. We find periculum and experitnentum given as Latin equivalents for prova in Pergamino, Giacomo, 17 memoriale della lingua italiana (Venice, 1617), p. 434 and Vocabolario degli accademici della Crusca, 2nd ed. (Venice, 1763), III, 529. Other relevant lexicographical information includes: Calepinus, Ambrosius, Dictionarium in quo restituendo atque exornando haec praestitimus … (Venice, 1571), II, 66v , which reads: ‘Periculum … Aliquando accipitur pro experimento [Esperienza, prova] …’, and Luc'Antonio Bevilacqua, Vocabulario volgare et latino … (Venice, 1571), 52r, which reads: ‘Prova, et pruova, sperienza.] periculum, experimentum. probatio. Far prova.] facere periculum.’ A further interesting example, this time in a French- Latin dictionary, is to be found in Estienne, Robert, Dictionarium Latinogallicum (Paris, 1538), 533 , which reads as follows: ‘Periculum, periculi, Peril, Danger … Facere periculum, Faire l'experience de quelque chose, Experimenter, Esprouver, Essayer.’

132 Eugenio Garin, ‘Gli umanisti e la scienza’.

133 The case with Newton was, of course, different as is becoming increasingly apparent. See especially McGuire, J. E. and Rattansi, P. M., ‘Newton and the “Pipes of Pan” ‘, Notes and Records of the Royal Society of London, XXI (1966), 108-143. Even Galileo, however, did not entirely escape from such influences, especially during the early part of his life before 1597—as much as the positivistically oriented historians of science would like to lead us to believe he did. E.g., see the recent and influential book by Ludovico Geymonat, Galileo Galilei (Turin, 1957; English trans, by Stillman Drake and Foreword by Giorgio de Santillana, New York, 1965). For a more accurate analysis of the situation see Garin, Scienza e vita civile …, pp. 147-170 (Galileo fdosofo), esp. pp. 156-158, 163,167.

134 It must be noted, as has been pointed out by A. Koyré, ‘An Experiment in Measurement’, Proceedings of the American Philosophical Society xcvn (1953), 222-237, a t 222-223 that the ‘empiricism of modern science is not experiential; it is experimental’ and that ‘its “empiricism” differs toto caelo from that of the Aristotelian tradition’.

135 In the opinion of the present writer Alexandre Koyré sometimes tended to do this. Consequently, an empirically oriented thinker such as Gassendi, with only a limited interest in mathematics and Platonic philosophy seems to be consistently underestimated. See his From the Closed World to the Infinite Universe (New York, 1958), 290 and his paper 'Gassendi: le savant’, in Pierre Gassendi: sa vie et son oeuvre, 1592-1655 (Paris, 1955), 60- 69, esp. 60. For the importance of Gassendi see especially Popkin, Richard H., The History of Scepticism from Erasmus to Descartes (Assen, 1960), I O I - I I I , 142-148 and Tullio Gregory, Scetticismo ed empirismo: studio su Gassendi (Bari, 1961).

136 In addition to the above analysis of Zabarella see my ‘Giulio Castellani (1528- 1586): A Sixteenth Century Opponent of Scepticism’, esp. 36, 39, where we see a 16thcentury Aristotelian siding with Lucretius to defeat scepticism. The present writer is not at all certain whether Professor Randall's statement, viz. ‘It is significant that the atomism of Lucretius was always held at Padua to be crudely unscientific’, The School of Padua … , p. 85, is entirely accurate. I plan to publish elsewhere the evidence for the influence of Lucretius and Atomism upon the Aristotelian natural philosophy of the Renaissance.

137 This, of course, disagrees fundamentally with the Cassirer-Randall thesis, which traces the dominant factors of Galileo's methodology to Paduan influences. I also find it difficult to see how the contention of William A. Wallace, op. tit., p. 263 n. 2 ('Galileo, of course, studied at the School of Padua and learned his methods of investigation there.’) is to be substantiated. If anything, Galileo studied at the ‘school of Pisa’ and learned his methods there. All too often in the literature, the ‘School of Padua’ seems to have an ideological, rather than a geographical reference—not wholly unlike the ‘School of Hard Knocks’. For an attempt to defend the Randall thesis against the substantial criticisms which it has received see William F. Edwards, ‘Randall on the Development of Scientific Method in the School of Padua—A Continuing Reappraisal’, in Naturalism and Historical Understanding: Essays in the Philosophy of John Herman Randall, Jr., ed. John P. Anton (State University of New York Press, Buffalo, 1967), pp. 53-68. It should be noted that later in his life Cassirer tended to see Galileo more as a type of'Platonist.’ See for example, his papers cited above in n. 109.

138 See Gilbert, Renaissance Concepts of Method, pp. 230-231. There is much to be said for Fr. Dubarle's argument that ‘Galilée, contrairement, à ce que Ton dit souvent, n'est pas le fondateur de la méthode expérimentale moderne. II a fondé la physique scientifique, mathématisée, sans avoir encore vraiment recours à la méthode expérimentale proprement dite.’ op. cit., p. 185. It is interesting to note that Antonio ∼Rocco,jilosofo peripatetico, criticized Galileo for not properly following the vie sensibili, as he claims to have done in the Dialogo sopra i due massimi sistetni. See Rocco's Esercitazionifilosofiche (Venice, 1633), as printed in Galilei, Opere, ed. Favaro, vn, 712.1 am indebted to Rev. William R. G. Shea for this reference.

* This paper is partly an outgrowth of research carried out with the aid of Grant No. 3809, Penrose Fund, American Philosophical Society. The generosity of this assistance is gratefully acknowledged. In one form or another it has been read on the following occasions: (1) 4 April 1967, to the Columbia University Seminar on the Renaissance; (2) 24 May 1968, to the Seminar on Methodology at University College, London; and (3) 5july 1968, to the British Society for the History of Science, Summer Meeting at Leeds University. In preparing it I have benefited greatly from the many helpful suggestions, criticisms, and comments of a number of scholars, especially the following: William F. Edwards, Neal W. Gilbert, Donald R. Kelley, Paul Oskar Kristeller, Edward P. Mahoney, J. R. Ravetz, Edward Rosen, William R. J. Shea, and Charles Webster.


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed