1 Volume 61, Boston Studies in the Philosophy of Science (Dordrecht, 1980).

2 Mahoney, Edward P., ed. and tr., “The Scholar and his Public in the Late Middle Ages and the Renaissance,” Medieval Aspects of Renaissance Learning: Three Essays by “ Paul Oskar Kristeller (Durham, North Carolina, 1974), pp. 12–13 Google Scholar. I have greatly benefited from Professor Kristeller's and Professor Mahoney's observations on a number of points in this essay.

3 See the discussion of the background of the letter in Stillman Drake, Discoveries and Opinions of Galileo (New York, 1957), pp. 145-171, and in Langford, Jerome, Galileo, Science and the Church (Ann Arbor, 1971), pp. 50–78 Google Scholar. Another quite different view is that of Koestler, Arthur, The Sleepwalkers (New York, 1968), pp. 415–463 Google Scholar. An earlier and very careful recapitulation of the events leading up to the trial is in von Gebler, Karl, Galileo Galilei and the Roman Curia, tr. Sturge, Mrs. George (London, 1879)Google Scholar.

4 The sermon was deplored by Luigi Maraffi, a preacher general of the Dominican Order. See Maraffi to Galileo in the National Edition of Galileo's works, Le Opere di Galileo Galilei (henceforth referred to as Opere), ed. Antonio Favaro, 20 vols, in 21 (Florence, 1890-1909, rpt. 1968), XII, 127-128.

5 Lorini to the Holy Office, Opere XII, 297ff

6 Castelli says that the Barnabite had promised passages from St. Augustine and other doctors who confirm Galileo's preferred interpretation of Joshua, developed in the earlier letter to Castelli, Opere XII, 126-127. Francois Russo conjectures that Galileo used St. Augustine's commentary on Genesis more frequently than the others because that was the source most sympathetic to his views, “Lettre a Christine de Lorraine Grande-Duchesse dc Toscane (1615),” Revue d'histoire des sciences, 17 (1964), 337.

7 Favaro examined 34 manuscript copies of the letter in preparing his edition; Opere V, 272-278, contains a discussion of these.

8 See the communication of Mathias Bernegger to Elio Diodati, December 1634, referring to the letter's forthcoming publication, Opere XVI, 168. According to Bernegger the letter was furnished by his and Galileo's friend Diodati, who translated it into Latin. One might conjecture that this was with Galileo's knowledge, but Favaro points out there is no evidence in Galileo's correspondence that he was aware of these preparations, Opere V, 275.

9 For discussions of the influence of ars dictaminis through the Renaissance see Kristeller, “The Scholar and his Public,” pp. 10-14, and “Humanism and Scholasticism in the Italian Renaissance” in his collected essays, Renaissance Thought and its Sources, Mooney, Michael, ed. (New York; 1979), pp. 85–105 Google Scholar. Seigel, Jerrold E. treats the topic in Rhetoric and Philosophy in Renaissance Humanism (Princeton, 1968)CrossRefGoogle Scholar, ch. 7. For the late Middle Ages see James J. Murphy, Rhetoric in the Middle Ages (Berkeley, 1974), ch. 5, and Witt, Ronald, “Medieval ‘Ars Dictaminis’ and the Beginnings of Humanism: A New Construction of the Problem,” Renaissance Quarterly, 35 (Spring 1982), 1–35 CrossRefGoogle Scholar. See also Wieruszowski, Helene, “Ars dictaminis in the Time of Dante,” Politics and Culture in Medieval Spain and Italy (Rome, 1971)Google Scholar.

10 Favaro's critical edition of the letter appears in Opere V, 309-348. For the convenience of the reader I have followed Drake's English translation in this essay, emending it occasionally for style and nuances in conformity with Favaro's version. (Drake's translation is in Discoveries, pp. 175-216). It was based on Thomas Salusbury's 1661 English translation and Favaro's edition.

11 The National Edition includes facsimiles of the Sidereus Nuncius in autograph and in its first printed edition, Opere III. 1, 15-96. Drake translated the work in Discoveries, pp. 23-58.

12 Drake's attitude is apparent in his introduction to the letter in Discoveries where he presents it as a valiant and uncompromising effort to describe the “proper relation of science to religion,” p. 145 (cf. p. 165). De Santillana places the letter on a plane with Milton's Areopagitica in his well known work on the trial, The Crime of Galileo (Chicago, 1955), pp. 96-98.

13 Favaro discusses the evidence for this, based on the draft of the Letter found in Codex Volpicelliano, Opere, V, 274-275.

14 Opere I, 412 [m. 17], English translation by Drake, in Mechanics in Sixteenth Century Italy (Madison, 1969), p. 382 Google Scholar. The same sentiment is sounded in Galileo's Dialogue on Motion of c. 1586-87, Opere I, 398, also in Mechanics, pp. 364-365.

15 Robert Westman, unpublished paper, “The Copernicans and the Churches: From De Revolutionibus to the Decree of 1616,” for the Carner Foundation— University of Wisconsin Conference on “Christianity and Science: Two Thousand Years of Conflict and Compromise,” Madison, 23-25 April 1981, pp. 8-10, 31. The thesis will be further developed in Professor Westman's forthcoming book, The Copernicans: Universities, Courts and Interdisciplinary Conflict, 1543-1700. In his Oberlin lecture on Aristotelianism, Kristeller makes the same point, emphasizing the fact that Galileo's new conception of a physics based on mathematics was thought to be an intrusion by a mathematician and astronomer upon the field of natural philosophy that had previously been separate from mathematics and astronomy (Renaissance Thought and Its Sources, pp. 48-49). See also the discussion of disciplinary rivalries among Florentine humanists and philosophers before Galileo's day in Seigel, pp. 68-98.

16 Opere V, 315, lines 2-3.

17 Here Galileo's enthusiasm carries him too far. Although, as is well known, Copernicus’ uncle was archbishop of Frauenburg and he himself was a canon of the cathedral there, the Polish astronomer was never ordained to the priesthood. Moreover, Galileo's first reference to Copernicus occurs in his Tractatio de caelo, Opere 1, 43, 47-48, an early work wherein he himself rejects outright the heliocentric teaching. Alistair Crombie provides a replica of the folio containing this reference in Galileo's own handwriting in his “Sources of Galileo's Early Natural Philosophy,” in Reason, Experiment, and Mysticism in the Scientific Revolution, Righini, M. L. Bonelli, and Shea, W. R., eds. (New York, 1975), facing p. 162 Google Scholar.

18 Westman, pp. 14-16. Garin's account of Tolosani's work is in his Rinascite e rivoluzioni. Movimenti culturali dal XIVal XVIIIsecolo (Bari, 1976), pp. 255-281, giving Tolosani's text on pp. 283-295.

19 Koestler, pp. 433-434. Koestler's treatment of Galileo's Letter to Christina and the character of the astronomer is too harsh, and his book has been countered in reviews by De Santillana, Drake, and others. Koestler does not distinguish carefully enough between the earlier version of the letter written to Castelli and the later one to Christina. On the other hand, De Santillana makes too much of the effect of the Letter to Christina on Cardinal Barberini, based on a conversation with Galileo recorded by Giovanfrancesco Buonamici in the latter's diary. A rereading of Buonamici's diary by a disinterested eye does not yield the interpretation that the Cardinal was persuaded by the letter to counsel the Holy Office against accusing Galileo of heresy in 1616; cf. De Santillana, pp. 203, 289, and Opere XV, i n .

20 Fragments of classical selections, probably written by Galileo as scholastic exercises at Vallombrosa, have been assembled by Favaro in Vol. 9 of the National Edition. The extent of Galileo's training in rhetoric at the University of Pisa is difficult to ascertain, and more research is required in this area. Angelo Fabroni provides a survey of the professors and texts used in Galileo's time in his history of the university, Historia Academiae Pisanae, 3 vols. (Pisa, 1791—1795), Vol. II, cap. 15. The principal rhetoricians who taught there were Francesco Robortello, Ciriaco Strozzi, Pietro Angelio Bargeo, and Aldo Manucci. Especially noteworthy is the fact that the funeral oration for Bargeo was delivered in 1595 by Jacopo Mazzoni (II, 431, n. 1), the close friend of Galileo and his father, which could indicate that Bargeo was also part of their circle. See notes 22 and 35, infra.

21 A translation of a passage from Isocrates, the Greek rhetorican, into Latin, probably done by Galileo during his student days, is in Opere IX, 283-284. Fabroni states that the translation of Isocrates into Latin was a part of the requirement introduced by Lorenzo Lippi at Pisa near the end of the fifteenth century (I, 373). The Rhetorica ad Herennium, Cicero's rhetorical works, and Quintilian's, were newly appreciated in the early Renaissance and commentaries on them again appeared; see the discussion in Kristeller, , Renaissance Thought, pp. 239 Google Scholar, 245-255, and Kennedy, George A., Classical Rhetoric and Its Christian and Secular Tradition from Ancient to Modern Times (Chapel Hill, 1980), pp. 195–217 Google Scholar. Aristotle's Rhetoric was part of the curriculum for universities in Italy in the sixteenth century according to the researches of Lisa Jardine, Studies in the Renaissance, 11 (1974), 31-62. In his “Rhetoric in the Middle Ages,” Speculum, 17 (1942), 1-32, Richard McKeon points out that close connections between rhetoric and logic lingered on into the Renaissance and beyond, 31-32. Kristeller also discusses this connection and notes that dialectical argument emerged in Italy about the same time as Humanism, Renaissance Thought, pp. 99-101.

22 Galileo was reared in a family with extensive cultural and literary contacts. His father was a lutcnist and musicologist, well acquainted with classical languages and mathematics, and their home was the frequent meeting place for the litterati of Pisa and Florence. Apart from his knowledge of Virgil, Ovid, and Seneca, Galileo was particularly interested in the essays of Berni, the comedies of Ruzzante, and the verse of Ariosto and Tasso. In 1588 he delivered two lectures at the Florentine Academy on the dimensions of hell as set out in Dante's Inferno, and while teaching at Pisa around 1590 he composed a satirical poem “Against wearing the toga.” These are included in Vol. 9 of the National Edition (pp. 31-57 and 212-223 respectively), along with his other literary and poetic compositions. Ludovico Geymonat describes Galileo's literary interests in Galileo Galilei: A Biography and Inquiry into his Philosophy of Science, S. Drake, tr. (New York: 1965), pp. 9-15. Even more polemical and rhetorical in style are two pseudonymous dialogues written in Tuscan dialect in 1605 and 1606, which Drake has shown to be Galileo's and which he regards as the astronomer's first published work; see his Galileo Against the Philosophers (Los Angeles, 1976).

23 The autograph is preserved in the collection of Galileiana at the Biblioteca Nazionale Centrale in Florence with the signature MS Gal. 27. Misled by a statement in Vincenzo Viviani's biography of Galileo, Favaro regarded it as a mere scholastic exercise composed while the young Pisan was studying at the Monastery of Vallombrosa, and published only a brief excerpt from it and a listing of the questions they contain, now generally referred to as the “Logical Questions,” in Opere IX, 279-282, 291-292.

24 Edwards’ transcription, with an introduction and commentary by William A. Wallace, is forthcoming. Another transcription has been made independently by Adriano Carugo, and a brief summary of its contents appears in Crombie's essay, “Sources of Galileo's Early Natural Philosophy,” pp. 171-175.

25 Drake, , Galileo at Work: His Scientific Biography (Chicago, 1978), p. 245 Google Scholar, and Discoveries, p. 167.

26 See Opere XII, 183-184; his letter is translated in Drake, , Discoveries, p. 167 Google Scholar.

27 Foscarini's defense of Copernicanism also took the form of a published letter. Its long title is Lettera del R.P.M. Paolo Antonio Foscarini Carmelitano Sopra I'Opinione de'Pittagorici e del Copernico, delta Mobilita della Terre e Stabilita del Sole, e del Nuovo Pittagorico Sistema del Mondo (Naples, 1615).

28 Notes made by Galileo and containing rebuttals of the various points in Bellarmine's letter have been transcribed by Favaro and published under the title Considerazioni circa Vopinione Copernicana, Opere V, 340-370; excerpts from this material are translated by Drake in Discoveries, pp. 167-170. The notes were probably written before Galileo revised his epistle to Castelli, but in any event Bellarmine's observations are all taken into account in the Letter to Christina.

29 Opere XII, 171; the letter is translated in Discoveries, pp. 162-164.

30 Opere XII, 173, 30.

31 See Opere XII, 171, line 32. That Galileo understood the precise meaning of this expression is clear from his commentary on the Posterior Analytics contained in the Logical Questions. The second treatise in this work is in fact entitled De demonstratione, and it consists of three disputations, the first on the nature and importance of demonstration, the second on its properties, and the third on its kinds (Opere IX, 2S0-281). W. A. Wallace has given the more important readings from this treatise and has traced their recurrence in Galileo's later writings on his “The Problem of Causality in Galileo's Science,” The Review of Metaphysics, 36 (1983), 607-632. Additional details are provided in his “Aristotle and Galileo: The Uses of γΠOθEIΣ (Suppositio) in Scientific Reasoning,” in Studies in Aristotle, Dominic O'Meara, cd. (Washington, D.C., 1981), pp. 47-77. I am indebted to Professor Wallace for discussions of this and other points related to Galileo's science and scientific reasoning.

32 Opere XII, 185; Drake, Discoveries, p. 166.

33 Ibid.

34 The Italian reads ”… quanto ella sia ben fondata sopra manifeste esperienze e necessarie dimostrazioni … “ (Opere V, 312, lines 27-28). In view of Galileo's understanding of the expression “necessarie dimostrazioni,” there is an ambiguity in this statement that will be exploited throughout the remainder of the Letter. As Galileo states it, the Copernican system is “well grounded” (ben fondata) on manifest experiences and necessary demonstrations. Does this mean that the system is actually demonstrated on the basis of sense experience, or that it is merely a plausible hypothesis that can be supported in part by observation and strict mathematical reasoning? The first is the impression Galileo intends to convey, as can be seen throughout the remainder of the Letter, whereas the second would be consonant with Bellarmine's understanding of the proofs Galileo and Foscarini were alleging, which would not be sufficient to evoke a wholesale reinterpretation of the Scriptures, as Galileo states in the Letter. The authority of the Bible, he says there, “ought to be preferred over that of all human writings which are supported only by bare assertions and probable arguments, and not set forth in a demonstrative way” (Opere V, 317, lines 21-24; Discoveries, p. 183). See also my comparision of Galileo's argumentation in the Letter with that employed in his Dialogue of 1632, “Galileo's Rhetorical Strategies in Defense of Copernicanism,” in Novita Celesti, Crisi del Sapere, Paolo Galluzzi, ed., forthcoming.

35 Galileo describes himself as an Aristotelian in his scientific reasoning in his letter of September 14, 1640, to Fortunio Liceti, Operc XVIII, 248; see the passage translated into English in Wallace, “Aristotle and Galileo,” p. 75. The “progressive Aristotelianism” of Galileo in matters methodological is delineated by Wallace, in his “Aristotelian Influences on Galileo's Thought,” in Aristotelismo Veneto e Scienza Moderna, Olivieri, Luigi, ed., 2 vols. (Padua, 1983), I, 349–378 Google Scholar. This is not to deny that Galileo was also influenced by Plato, as has been noted by Kristeller in his Renaissance Thought, p. 64 and notes 47 and 48 on pp. 269-270, and also urged by Koyre, Alexandre in his Metaphysics and Measurement: Essays in the Scientific Revolution (Cambridge, Mass., 1968), pp. 16–43 Google Scholar. During Galileo's days at Pisa the oppositions between Aristotelianism and Platonism were not as clearly noted as they arc in our times; both Jacopo Mazzoni and Cosimo Boscaglia taught Aristotle and Plato at the university there, and Mazzoni even attempted a complete reconciliation of the two philosophers. Galileo studied with Mazzoni in 1590, as he records in his letter to his father on November 15th of that year (Opere X, 44-45), and seems to have been particularly impressed with the way in which his father's friend used mathematics to remove impediment to man's knowledge of the physical world. For more details, sec Purnell, Frederick, “Jacopo Mazzoni and Galileo,” Physis, 3 (1972), 273–294 Google Scholar.

36 Augustin Cardinal Bea, S.J., in fact, speaks of Providentissimus Deus as “the Magna Carta of biblical studies” for the Catholic Church; see his Foreword to The Jerome Biblical Commentary, Brown, Raymond E. et al., eds. (Englewood Cliffs, N.J., 1968)Google Scholar, the standard text now in use in Catholic seminaries.

37 So frequently does Galileo refer to “necessary demonstration” and “sensate experience” throughout the Letter that these expressions form almost a litany to mesmerize his readers. A partial list of their occurrence, or that of equivalent expressions, follows: ”… trattate con astronomiche e geometriche dimostrazioni, fondata prima sopra sensate esperienze e j aCcuratissime osservazioni” (Opere V, 313, lines 23-25); ”… cominciare … dalle sensate esperienze e dalle dimostrazioni nccessarie” (p. 316, lines 24-25); ”… effetti naturali che o la sensata esperienza ci pone dinanzi a gli occhi o le necessarie dimostrazioni ci concludono …” (p. 317, lines 1-2); ”… venuti in certezza di alcune conclusioni naturali …” (p. 317, lines 12-13); “in quelle conclusion! naturali, che o dalle sensate esperienze o dalle necessarie dimostrazioni ci vengono esposte innanci a gli occhi e all'intelletto …” (p. 317, lines 29-31); ”… delle infinite conclusioni ammirande che in tale scienza si contengono e si dimostrano …” (p. 318, lines 9-10); ”… quanto nelle conclusioni naturali si devono stimar le dimostrazioni necessarie e le sensate esperienze … “ (p. 319, lines 29-31); ”… che indubitabilmente saranno concordanti con quelle conclusioni naturali, delle quali il senso manifesto o le dimostrazioni necessarie ci avessero prima resi certi e sicuri” (p. 320, lines 13-16); ”… quelle conclusioni naturali, delle quali una volta il senso e le ragioni dimostrative e necessarie ci potessero manifestare …” (p. 320, lines 23-25); ”… con molte osscrvazioni e dimostrazioni confermata …” (p. 321, lines 14—15); ”… che sarebbe nccessaria prima a capire … lc dimostrazioni con le quali le acutissime scienze procedono …” (p. 321, lines 26-28); ”… le conclusioni dimostrate circa le cose della natura e del cielo …” (p. 326, lines 18-19); “... alcune cose della natura dimostrate veracemente … “ (p. 327, lines 13-14); ”… o si ha, o si puo credere fermamente che aver si possa, con esperienze, con lunghe osservazioni e con necessarie dimostrazioni, indubitata certezza, quale e, se la Terra e ‘1 Sole si muovino o no …” (p. 330, lines 17-20); ”… si deva considerar se elle sono indubitabilmente dimostrate o con esperienze sensate conosciute . . ,” (p. 332, lines 5-6); ”… esquisite osservazioni e sottili dimostrazioni …” (p. 332, lines 12-13); “... dopo aver prima dimostrato che i movimenti li quali a noi appariscono esser [sic] del Sole o del firmamento son veramente della Terra …” (p. 334, line 24-335, line 1)” “... l'espericnze, l'osservazioni, le ragioni e la dimostrazioni de’ filosofi ed astronomi … “ (p. 338, lines 7-8); ”… definire conclusioni naturali, delle quali, o con esperienze o con dimostrazioni necessarie, si potrebbe in qualche tempo dimostrare il contrario …” (p. 338, lines 33-35); ”… negare l'esperienze e le dimostrazioni necessarie” (p. 339, line 19); ”… aver molte esperienze sensate e molte dimostrazioni necessarie per la parte sua … “ ( p . 341, lines 32-33); ”… oppugnar le manifeste esperienze o le necessarie dimostrazioni” (p. 342, lines 12-13). Only once in this long list does Galileo state that natural conclusions might in time (si potrebbe in qualche tempo, p. 338, line 35) be demonstrated to be contrary to the sense of Scripture; in all other cases he conveys the impression that demonstrations based on sense experience were or actually are available to determine the sense in which the Bible is to be understood.

38 See the many references to the work of Tycho Brahe throughout the National Edition, Opere XX, 98-99. In the Tychonian system the earth is posited as stationary at the center of the universe, but the planetary spheres rotate around the sun, and the whole ensemble, together with the moon, around the earth. Many were attracted to the theory, which had the advantage of not contradicting Scripture; on this ground it was clearly favored by Jesuit astronomers.

39 The usual evidence cited is Foucault's experiments with pendulums swinging freely on the earth's surface and Besscl's measurements of stellar parallax, both of which date from the nineteenth century; see, however, Giorgio Tabbaroni, “Giovanni Battista Guglielmini e la prima verifica sperimentale della rotazione terrestrc (1790),” Angelicum, 60 (1983), 462-486. All are agreed that Galileo's argument from the tides, hinted at in the Letter to Christina (Opere V, 311, lines 6-8; Discoveries, p. 177) and explained in his discourse addressed to Cardinal Orsini on 8 January 1616, Del fltisso e refiusso del mare (Opere V, 377-395), and again in the Dialogue of 1632, is defective. On this matter, see Shea, William R., Galileo's Intellectual Revolution: The Middle Period, 1610-1632 (New York, 1972), pp. 172–189 Google Scholar, and the more recent analysis of Galli, Mario G., “L'argomentazione di Galileo in favore del sistema copernicano dedotta dal fenomeno delle maree,” Angelicum, 60 (1983), 386–427 Google Scholar.

40 This interpretation has been advanced by W. A. Wallace in two recent articles: “Galileo's Science and the Trial of 1633,” The Wilson Quarterly, 7 (1983), 154-164; and “Galileo and Aristotle in the Dialogo,” Angelicum, 60 (1983), 311-332. Wallace's view differs from that of Finocchiaro, who argues on the basis of the Dialogue that Galileo never intended to produce demonstrative proofs but was content with plausible or rhetorical arguments from beginning to end. Wallace, on the other hand, notes a change in Galileo's aspirations after the decree of 1616 against Copernicus. Prior to the decree, as in the Letter to Christina, he spoke as if necessary demonstrations based on sense experience were already, or soon would be, available; after it, as in the Dialogue, he attenuated his claims considerably. For additional details, see Wallace's review of Finocchiaro's book, Journal of the History of Philosophy, 20 (1982), 307-309.

41 The expression Bellarmine uses, which Drake translates as “hypothetically,” is the technical Latin phrase ex supposition (Opere XII, 171, line 92), which can take on a variety of meanings. In his examination of the various points made by Bellarmine in the letter to Foscarini, Galileo distinguishes two senses of suppositio (supposizione, in Italian), one of which would lead to a merely hypothetical conclusion, the other to a demonstrated result (Opere V, 357-359). Professor Wallace has shown in his Prelude to Galileo (Dordrecht, 1981) that Galileo was unable to authenticate the suppositions on which his proofs for the earth's motion were based, whereas he was eventually successful in doing so for the demonstration of the law of falling bodies in the Two New Sciences of 1638 (pp. 129-159). For fuller details and documentation, see Wallace's “Aristotle and Galileo” and his Galileo and His Sources: The Heritage of the Collegio Romano in Galileo's Science, forthcoming from Princeton University Press.

42 This citation was unfortunate, for, unknown to Galileo, Zuniga had been vigorously reprimanded by the Jesuit theologian Juan de Pineda in his Commentariorum in lob libri tredecim (Coloniae Agrippinae, 1600, p. 340). The latter's work was well known and Bellarmine himself possessed a copy. Since Zuniga's Commentaries on Job was singled out for correction in the 1616 decree, Galileo's citation may have actually had the effect of increasing the oppostion to Copernicanism. Westman discusses this issue in his “The Copernicans and the Churches,” pp. 23-24, 39, 48, n. 46.

43 One of the consultants to the Inquisition, Melchior Inchofcr, regarded the Letter to Christina as prime evidence at the trial for Galileo's heretical teachings, Opere XIX, 349-

44 Quoted by D'Elia, Pasquale M., Galileo in China. Suter, Rufus and Sciasa, Matthew, eds. and trs. (Cambridge, Mass., 1960), pp. 57–58 Google Scholar.

45 Quoted in Langford, p. 58.