Galileo,Bruno and the Rhetoric of Dialogue in Seventeenth-Century Natural Philosophy

Leibniz Gottfried Wilhelm , Pacidius Philalethi: Prima de motu philosophia (1676) in The labyrinth of the continuum writings on the continuum problem, 1672–1686, by Leibniz G. W. , ed. and transl. by Arthur Richard T. W. (New Haven and London, 2001), 128–31: “Cum nuper apud illustres viros asseruissem, Socraticam disserendi methodum, qualis in Platonicis Dialogis expressa est, mihi praestantem videri: Nam et veritatem animis familiari sermone instillari, et ipsum meditandi ordinem, qui a cognitis ad incognita procedit, apparere dum quisque per se nemine suggerente vera respondet, modo apte interrogetur, rogatus sum ab illis, ut specimine edito rem tantae utilitatis resuscitare conarer, quae ipso experimento ostendit inedita mentibus scientiarum omnium semina esse. Excusavi me diu, fassus difficultatem rei majorem quam credi posit; facile enim esse dialogos scribere, quemadmodum facile est temere ac sine ordine loqui; sed oratione efficere, ut ipsa paulatim e tenebris eniteat veritas, et sponte in animis nascatur scientia, id vero non nisi illum posse, qui secum ipse accuratissime rationes inierit, antequam alios docere aggrediatur.” I have altered the translation slightly, rendering anima as ‘mind’ rather than ‘soul’.

Galilei Galileo , Dialogo di Galileo Galilei Linceo matematico sopraordinario dello studio di Pisa. E filosofo, e matematico primario del serenissimo Gr. Duca di Toscana. Doue ne i congressi di quattro giornate si discorre sopre i due massimi sistemi del mondo Tolemaico, e Copernicano;: Proponendo indeterminatamente le ragioni filosofiche, e naturali tanto per l'vna, quanto per l'altra parte (Florence, 1632; hereafter: Dialogo). The copy I have consulted is in the Special Collection of the University of London Library, shelfmark [S.L.] I [Galilei — 1632].

Galilei Galileo , Discorsi e dimonstrazioni matematiche intorno a due nuove scienze attenenti alla mecanica e i movimenti locali (Leiden, 1638; hereafter: Discorsi).

See, for example the works of Gross Alan G. : Science and rhetoric (Cambridge, MA and London, 1990) and Starring the text: The place of rhetoric in science studies (Carbondale, 2006). See also Hallyn Fernand , Les structures rhétoriques de la science: De Kepler à Maxwell (Paris, 2004); Pera Marcello , Scienza e retorica (Rome, 1991), transl. by Botsford Clarissa as Discourses of science (Chicago, 1994); Pera Marcello Shea William R. (eds), Persuading science: The art of scientific rhetoric (Canton, MA, 1991); and Schuster John A. Yeo Richard R. , The politics and rhetoric of scientific method: Historical studies (Australasian Studies in History and Philosophy of Science, 4; Dordrecht and Lancaster, 1986).

See Crombie Alistair C. Carugo Adriano , “Galileo and the art of rhetoric”, Nouvelles de la république des lettres, ii (1988), 7–31, reprinted in A. C. Crombie, Science, art and nature in mediaeval and modern thought (London and Rio Grande, 1996), 231–55; Vickers Brian , “Epideictic rhetoric in Galileo's Dialogo“, Annali dell'Istituto e Museo di Storia della Scienza di Firenze, viii (1983), 1983–102; Moss Jean Dietz , “The rhetoric of proof in Galileo's writings on the Copernican system”, in The Galileo affair: A meeting of faith and science, Proceedings of the Cracow Conference, May 24–27, 1984, ed. by Coyne G. V. (Vatican City, 1985), 41–65; Andrea Battistini, Galileo e i gesuiti: Miti letterari e retorica della scienza (Milan, 2000); and Baffetti Giovanni , Retorica e scienza: Cultura gesuitica e seicento italiano (Bologna, 1997).

See, for example, Snyder Jon R. , Writing the scene of speaking: Theories of dialogue in the late Italian Renaissance (Stanford, CA, 1989); Guthmüller Bodo Müller Wolfgang G. (eds), Dialog und Gesprächskultur in der Renaissance (Wolfenbütteler Abhandlungen zur Renaissanceforschung, 22; Wiesbaden, 2004); Kushner Eva , Le dialogue à la Renaissance: Histoire et poetique (Cahiers d'Humanisme et Renaissance, 67; Geneva, 2004); Godard Anne , Le dialogue à la Renaissance (Paris, 2001); Wilson K. J. , Incomplete fictions: The formation of English Renaissance dialogue (Washington, D.C., 1985); Marsh David , The quattrocento dialogue (Cambridge, MA, 1980); and Armstrong C. J. R. , “The dialectical road to the truth: The dialogue”, French Renaissance studies (Edinburgh, 1976), 36–51.

Despite the promise of their titles, neither Cox Virginia , The Renaissance dialogue: Literary dialogue in its social and political contexts, Castiglione to Galileo (Cambridge, 1992), nor Emanuele Zinato, Il vero in maschera: Dialogismi Galileiani: Idee e forme nelle prose scientifiche del seicento (Naples, 2003), has much to say about Galileo and the dialogue.

Finocchiaro Maurice A. , Galileo and the art of reasoning: Rhetorical foundations of logic and scientific method (Boston Studies in the Philosophy of Science, 61; Dordrecht, 1980).

Finocchiaro , Art of reasoning (ref. 8), 116–17. He makes some brief remarks about the nature of “Socratic cross-examination” on p. 172 (“Socratic method and unconscious knowledge”), but he doesn't develop this into a consideration of Galileo's adoption of this form of argument, where “the person involved is being forced to reason about the rationale underlying his beliefs”.

Galilei Galileo , Galileo On the Two World Systems: A new abridged translation and guide, transl. and ed. by Finocchiaro Maurice A. (Berkeley, Los Angeles and London, 1997), 81. Galileo , Dialogo, “Al Discreto Lettore” (unsigned sheets inserted before sig. A): “Ho poi pensato tornare molto a proposito lo spiegare questi concetti in forma di Dialogo, che per non esser ristretto alla rigorosa osseruanza delle leggi Matematiche, porge campo ancora a digressioni tal hora non meno curiose del principio argomento”.

Letter of Galileo to Elia Diodati, October 1629, in Drake Stillman , Galileo at work: His scientific biography (Chicago and London, 1978), 310.

Galileo , World Systems (ref. 10), 203, fn. 165. See also Finocchiaro Maurice A. , The Galileo Affair: A documentary history (Berkeley, 1989), 278.

See Finocchiaro , Art of reasoning (ref. 8), “The title, or the rhetoric of indecision”, pp. 12–18.

Galileo , World Systems (ref. 10), 153. Dialogo, 124–5: “[I]n questi discorsi of da Copernichista, e lo imito quasi sua maschera; ma quello che internamente abbiano in me operato le ragioni, che par ch'io produca in suo fauore non voglio che voi lo giudichiate dal mio parlare mentre siamo nel feruor della rappresentazione della fauola, ma dopo che aur deposto l'abito, che forse mi trouerete diuerso da quello, che mi vedete in scena”.

Galileo , World Systems (ref. 10), 82.

Patterson Annabel , Censorship and interpretation: The conditions of writing and reading in early modern England (Madison, WI, 1984), 45. Patterson sees these strategies as part of a “hermeneutics of censorship” which leads authors to develop “a highly sophisticated system of oblique communication, of unwritten rules whereby writers could communicate with readers or audiences (among whom were the very same authorities who were responsible for state censorship) without producing a direct confrontation” (ibid.). Although Patterson's remarks are aimed at state censorship in early modern England, they are extraordinarily pertinent to the ecclesiastical censorship practised in Galileo's Italy.

Galileo , World Systems (ref. 10), 101; Dialogo, 45–46.

Galileo , World Systems (ref. 10), 82; Dialogo, “Al Discreto Lettore”.

Finocchiaro , Art of reasoning (ref. 8), 5.

For an example of Finocchiaro's qualification of his approach see Art of reasoning (ref. 8), 66: “nonlogical rhetorical devices have their own standards of value; hence, though the pure logician, may act as if they did not exist, the concrete logician or theorist of reasoning, cannot do so”.

Finocchiaro , Art of reasoning (ref. 8), 70–71.

Finocchiaro , Art of reasoning (ref. 8), 70.

See Finocchiaro , Art of reasoning (ref. 8), 4–5, and chap. 8, 180–201.

Finocchiaro , Art of reasoning (ref. 8), 44. See chap. 7, “The primacy of reasoning: The logical character of Galileo's methodology”, pp. 167–79, and chap. 16, “Galileo as a logician: A model and a data basis”, pp. 343–412.

de Santillana Giorgio , The crime of Galileo (Chicago, 1955), 174, cited by Finocchiaro , Art of reasoning (ref. 8), 27.

Finocchiaro has a brief paragraph on digression on p. 118 (“Fanciful vs. relevant digressions”) which he includes as part of an inventory of “methodological topics”. He merely notes that “There are two kinds of digressions: Some are justified by their relevance to the main argument and by the logic of the discussion…. Others are justified by the whim of the writer or persons involved or by the intrinsic beauty rather than by the reasoned tenability of the ideas involved…. The digressions up to this point have been typically of the first type”. He makes no attempt to analysis the digression as a rhetorical strategy, or to explain the contrast which Galileo makes between the digression and the “rigorous observation of mathematical laws”.

Moss Jean Dietz , Novelties in the heavens: Rhetoric and science in the Copernican controversy (Chicago, 1993), 268.

Finocchiaro , Art of reasoning (ref. 8), 23–24.

See Finocchiaro , Art of reasoning (ref. 8), 46, 56.

Galileo , World Systems (ref. 10), fn 71, p. 147. For a fuller treatment of the rhetorical dimension of Galileo's natural philosophy see Finocchiaro , Art of reasoning (ref. 8).

Cassirer Ernst , Zur Logik der Kulturwissenschaften: Fünf Studien (1942), transl. by Lofts S. G. as The logic of the cultural sciences: Five studies (New Haven and London, 2000), pp. 53–54.

Koyré Alexandre , Études Galiléennes (Paris, 1966, repr. 2001), 212: “Le Dialogue sur les deux plus grands systèmes du monde prétend exposer deux systèmes astronomiques rivaux. Mais, en fait, ce n'est pas un livre d'astronomie, ni même de physique. C'est avant tout un livre de critique; une oeuvre de polémique et de combat; c'est en même temps une oeuvre pédagogique [et] une oeuvre philosophique…”.

Quintilian had identified the various advantages of introducing “fictional personages” into an oration in the Institutio oratoria (IX.1): “by the introduction of fictitious personages we may bring into play the most forcible form of examination. We may describe the results likely to follow some action, introduce topics to lead our hearers astray, move them to mirth or anticipate the arguments of our opponent.” See The Institutio Oratoria of Quintilian, transl. by Butler H. E. (4 vols, London, 1921–22), iii, 365.

Galileo , World Systems (ref. 10), 174; Dialogo, 185.

Galileo , World Systems (ref. 10), 178; Dialogo, 188.

Galileo , Discorsi, 32; Galileo Galilei. Two new sciences. Including Centers of gravity and Force of percussion, transl. by Drake Stillman (Madison, 1974), 40.

See Galileo , Discorsi, 14, 19; Two new sciences (ref. 36), 22, 26.

Galileo , World Systems (ref. 10), 88; Dialogo, 27.

Moss , Novelties (ref. 27), 298.

Galileo , World Systems (ref. 10), 72; Discorsi, 69.

Galileo , Two new sciences (ref. 36), 35; Discorsi, 27: “Salu. … mà forse il diuertir tanto lungamente dal cominciato cammino potrebbe parerui importuno, e però poco grato. Sagr. Di grazia godiamo del benefizio, e priuilegio, che s'hà dal parlar con i viui, e tra gli amici, e più di cose arbitrarie, e non necessarie, differente dal trattar co'i libri morti, li quali ti eccitano mille dubii, e nissuno te ne risoluono. Fateci dunque partecipi di qulle considerazioni, che il corso de i nostri ragionamenti vi soggreisce…”.

On quaestiones disputatae, and other mediaeval genres of Aristotelian philosophical writing inherited by Renaissance authors see Schmitt Charles B. , “Aristotelian literature”, in his Aristotle in the Renaissance (Cambridge, MA, 1983), 34–63. See also Lawn Brian , The rise and decline of the scholastic Quaestio disputata: With special emphasis on its use in the teaching of medicine and science (Education and Society in the Middle Ages and Renaissance, 2; Leiden, 1993).

Galileo , World Systems (ref. 10), 121; Dialogo, 101. On centonismo see Hoch Christoph , Apollo Centonarius: Studien und Texte zur Centodichtung der italienische Renaissance (Tübingen, 1997).

Galileo , World Systems (ref. 10), 127–8; Dialogo, 106.

Wallace William A. , in Galileo's logic of discovery: The background, content, and use of his appropriated treatises on Aristotle's Posterior analytics (Boston Studies in the Philosophy of Science, 137; Dordrecht, 1992), has argued that Galileo was profoundly indebted to the Aristotelian tradition, and William E. Carroll has recently argued that Galileo's “challenging” of Aristotelian orthodoxy is a “myth” masking an essential indebtedness to Aristotelian methodology. See Carroll William E. , “Galileo Galilei and the myth of orthodoxy”, in Brooke John MacLean Ian (eds), Heterodoxy in early modern science and religion (Oxford, 2005), 115–44.

Galileo , World Systems (ref. 10), 126–7; Dialogo, 105–6.

Galileo , Two new sciences (ref. 36), 38–39; Discorsi, 31: “[E] però con la solita libertà sia lecito produrre in mezzo i nostri humani capricci, che tali meritamente possiamo nominargli in comparazione delle dottrine sopranatturali, sole vere, e sicure determinatrici delle nostre controuersie, e scorte inerranti ne i nostri oscuri, e dubbii sentieri, ò più tosto Labirinti”.

On the prevalence of argument in utramque partem in early modern rhetoric see Skinner Quentin , Reason and rhetoric in the philosophy of Hobbes (Cambridge, 1996), 9–10.

Galileo , World Systems (ref. 10), 119; Dialogo, 100.

Galileo , World Systems (ref. 10), 118; Dialogo, 100.

Finocchiaro , Art of reasoning (ref. 8), 15–16.

Moss , Novelties (ref. 27), 266, fn 21.

Moss , Novelties (ref. 27), 267.

For Cicero's probabilism see, for example, Tusculan Orations, II, ii, 5: “we, however, whose guide is probability and who are unable to advance further than the point at which the likelihood of truth has presented itself, are prepared both to refute without obstinacy and be refuted without anger [nos, qui sequimur probabilia nec ultra quam ad id, quod veri simile occurrit, progredi possumus, et refellere sine pertinacia et refelli sine iracundia parati sumus]. Cicero, Tusculan disputations, transl. by King J. E. , (Cambridge, MA, and London, 1996), 150–3.

For Salviati's explicit references to the digressive nature of the discussion see, for example, Galileo , World Systems (ref. 10), 106, 117, 127–8, 202; Dialogo, 49, 99, 106, 205.

Galileo , World Systems (ref. 10), 128; Dialogo, 106. My emphasis.

Galileo , World Systems (ref. 10), 87; Dialogo, 26–7.

Galileo , World Systems (ref. 10), 90; Dialogo, 29.

Ibid.

Galileo , World Systems (ref. 10), 96; Dialogo, 42.

Galileo , World Systems (ref. 10), 224; Dialogo, 317.

Galileo , World Systems (ref. 10), 98; Dialogo, 43–44.

Galileo , World Systems (ref. 10), 105; Dialogo, 48.

See, for example, Galileo , World Systems (ref. 10), 242; Dialogo, 331: “Sagr. Oh, Nicolaus Copernicus, how pleased you would have been to see this part of your system confirmed by such clear observations!” and World Systems, 245; Dialogo, 349: “Salv. … Look at the reckless arrogance of certain people! They undertake the confutation of someone else's doctrine but misunderstand its primary foundations …”.

Galileo , World Systems (ref. 10), 120; Dialogo, 101.

Galileo , World Systems (ref. 10), 155; Dialogo, 126.

Two new sciences (ref. 36), 86; Discorsi, 83–84: “Sagr. Non questa sola, mà molte altre insieme dalle vostre proposizioni son così remote dalle opinioni, e dottrine communemente riceuute, che spargendosi in publico vi conciterebber numero grande di contradittori: Essendo che l'innata condizione de gli huomini non vede con buon'occhio, che altri nel loro esercizio scuopra verità, ò falsità non scoperte da loro; e col dar titolo di in- | nouatori di dottrine poco grato à gli orecchi di molti, s'ingegnano di tagliar quei nodi, che non possono sciorre, e con mine sutterranee dissipar quelli edifizij, che sono stati con gli strumenti consueti da pazienti artefici costrutti: Mà con esso noi lontani da simili pretensioni l'esperienze vostre, e le ragioni bastano à quietarci: Tuttauia quando habbiate altre più palpabili esperienze, e ragioni più efficaci le sentieremo molto volontieri”.

Two new sciences (ref. 36), 161 (slightly modified); Discorsi, 165.

See Grassi Orazio , Ratio Ponderum librae et simbellae: In qua quid e L. Sarsii libra astronomica, quidque e Galilei simbellatore, de cometis statuendum sit, collatis utriusque rationum momentis, Philosophorum proponitur (Paris, 1628), See Examen XLI, 156: “id vnum tamen scio scholam illam, quam bonam, praeclaro nomine appellat Galileus, Epicuri scholam fuisse, hominis eo omnia dirigentis, vt aut Deum tolleret, aut illum mundi cura leuaret.” See also Examen XLVIII, 172–182, esp. p. 179: “Sed quoniam in hac noua philosophandi ratione, plus aliquid audendum videtur, quam in veteri illa, ac religiosa nimis”, and p. 173: “Nunc me illa voca de calore digressio, in qua se è schola Democriti, atque Epicuri vnum profitetur Galilaeus” [marg. gloss “Sag. f. 196, l.26”]. On p. 174 he argues that Galileo's views contradict Catholic doctrine on transubstantiation.

Two new sciences (ref. 36), 34; Discorsi, 26.

Bruno Giordano , La Cena de le Ceneri. Descritta in cinque dialogi, per quattro interlocutori, Con tre considerationi, Circa doi suggettj (London: 1584). All translations here are from La Cena de le Ceneri. The Ash Wednesday Supper, Giordano Bruno, ed. and transl. by Gosselin Edward A. Lerner Lawrence S. (Hamden, CT, 1977; repr. Toronto, 1995; hereafter: Ash Wednesday). All cross-references to the Italian text refer to the Belles Lettres edition: Le Souper des Cendres, ed. by Aquilecchia Giovanni , in Giordano Bruno, Oeuvres complètes, ii (Paris, 1994; hereafter: Souper).

See Bruno , Ash Wednesday, 85, where Teofilo says of “the Nolan” (i.e. Bruno) that “he saw through neither the eyes of Copernicus nor those of Ptolemy” (cf. Souper, 37); or Ash Wednesday, 192: “‘I care little about Copernicus,’ said the Nolan, ‘and little care whether you or others understand him.”’ (cf. Souper, 227). On Bruno's problematic relationship to Copernicanism, see Hélène Védrine, La conception de la nature chez Giordano Bruno (Paris, 1967), 216–36; Westman Robert S. , “Magical reform and astronomical reform: The Yates thesis reconsidered”, in Hermeticism and the Scientific Revolution. Papers read at a Clark Library Seminar, March 9 1974 by Westman Robert S. McGuire J. E. (Los Angeles, 1977), 5–91; and Granada Miguel A. , “Giordano Bruno, Thomas Digges e il copernicanismo in Inghilterra”, in Giordano Bruno 1583–1585: The English experience / L'esperienza inglese, ed. by Ciliberto Michele Mann Nicolas (Florence, 1997), 125–55. See also, more recently, Knox Dilwyn , “Ficino, Copernicus and Bruno on the motion of the earth”, Bruniana et Campanelliana, v (1999), 1999–66; Knox Dilwyn , “Bruno's doctrine of gravity, levity and natural circular motion”, Physis, xxxviii (2001), 2001–209 (esp. pp. 200–8); and Tessicini Dario , I dintorni dell'infinito: Giordano Bruno e l'astronomia del cinquecento (Bruniana et Campanelliana Supplementi, 20, Studi, 9; Pisa and Rome, 2007).

Ricci Saverio , La fortuna del pensiero di Giordano Bruno 1600–1750 (Naples, 1990), 96–110. On the ‘affinity’ (affinità) between some of Galileo's arguments in the Dialogo and Bruno's De l'infinito, see ibid., 98–99.

Ricci , Fortuna (ref. 73), 106–10.

Gatti Hilary , “Giordano Bruno's Ash Wednesday Supper and Galileo's Dialogue of the two Major World Systems”, Bruniana e Campanelliana, iii (1997), 283–300, p. 284. For another comparison of Bruno and Galileo see Rossi Arcangelo , “Bruno, Copernico e Galilei”, Physis, xxxviii (2001), 2001–303.

For a facsimile reproduction of the title page see Bruno , Souper, 1.

Bruno , Ash Wednesday, 68; Souper, 9, 11.

Bruno , Ash Wednesday, 68; Souper, 19, 21.

Bruno , Ash Wednesday, 72; Souper, 11.

Bruno , Ash Wednesday, 69; Souper, 11, 13. Bruno describes this dialogue as a “moral topography [una topografia morale]”, which his reader must discern “with Lynceus's eyes”.

Bruno , Ash Wednesday, 73; Souper, 21.

Bruno , Ash Wednesday, 84; Souper, 35.

Bruno , Ash Wednesday, 93; Souper, 57. Cf. Gatti, op. cit. (ref. 75), 290: “Galileo's Simplicio is in many ways a direct development of Bruno's fiercely caricatured neo-Aristotelians, Torquato and Nundinius and even more of his cautious Prudentius”.

Bruno , Ash Wednesday, 182–3 (Latin slightly amended); Souper, 205.

Bruno , Ash Wednesday, 183; Souper, 205.

For the use of Erasmian adages see Bruno , Ash Wednesday, 186–7; Souper, 213–15, and for Osiander see Ash Wednesday, 137–9; Souper, 127–131.

Bruno , Ash Wednesday, 189; Souper, 223.

Bruno , Ash Wednesday, 137; Souper, 127.

Bruno , Ash Wednesday, 92–93, 153, 157; Souper, 55, 161–3, 173.

Bruno , Ash Wednesday, 153; Souper, 161.

Bruno , Ash Wednesday, 97; Souper, 65: “[N]on voglio ch'abbino facultà di esercitar atti de interrogatore o disputante, prima ch'abbino udito tutto il corso de la filosofia: Per che all'ora se la dottrina è perfetta in sé, e da quelli è stata perfettamente intesa, purga tutti i dubii, e toglie via tutte le contradizzioni … non è possibile saper, circa una arte o scienza, dubitar et interrogar a proposito, e co gli ordini che si convengono, se non ha udito prima”.

Bruno , Ash Wednesday, 97; Souper, 67.

Bruno , Ash Wednesday, 98–99; Souper, 67–71.

Bruno , Ash Wednesday, 99; Souper, 71–73.

Galileo , World Systems (ref. 10), 233–4; Dialogo, 324.

Galileo , World Systems (ref. 10), 106; Dialogo, 49.

Galileo , Discorsi, “Lo stampatore ai lettori”, sig. *3 verso: “Parimente quelli, i quali con l'acutezza dei loro ingegni, hanno riformato le cose già trouate, scoprendo le fallacie, & gli errori, di molte età, sono degni di gran lode, & ammiratione: Atteso medesimamente, che tale scoprimento, è laudabile, se bene i medesimi scopritori, hauesseno solamente rimossa la falsità, senza introdurne la verità, per se, tanto difficile à conseguirsi; conforme al detto del principe de gl'oratori. Vtinam tam facilè possem vera repirire, quam falsa convincere.” The Latin quotation is from Cicero, De natura deorum, I, 91.

Galileo , World Systems (ref. 10), 88; Dialogo, 27.