Introduction

Historians and their historical actors have spilled much ink detailing what it was like to experience the upheavals in early modern science once commonly referred to as the Scientific Revolution. The period’s innovators, Galileo Galilei (1564–1642), René Descartes (1596–1650), Francis Bacon (1561–1626), and others, described it as a great struggle, one pitting new methods and insights against the sterile learning and stubbornness of university-trained Aristotelians committed to Scholastic and humanist textual methods. One example to consider is Galileo’s criticism of his Jesuit rival Orazio Grassi (1583–1654), addressed by the pseudonym Lotario Sarsi, in his 1623 Saggiatore: “I seem to detect in Sarsi the firm belief that in philosophizing one must rely upon the opinions of some famous author. . . . Perhaps he thinks that philosophy is the creation of a man, a book like the Iliad or Orlando Furioso. . . . Mr. Sarsi, that is not the way it is. Philosophy is written in this all-encompassing book that is constantly open before our eyes, that is the universe. . . . It is written in mathematical language.”Footnote ¹ Galileo’s criticism in this passage and elsewhere focuses on the methodological differences between his approach to the study of the natural world and that of his opponents. He claims to be describing the world quantitatively and to be relying on sensory experience to verify his speculations. Sarsi, in his view, carries out an exercise in textual exegesis where the veracity of a claim is measured by its agreement with the opinions of established textual authorities.

Galileo’s vision, one shared by other period innovators, encouraged their peers and successors to value novelty and reject traditional textual learning. So, too, as historians have argued, did such visions shape the historiography of early modern science.Footnote ² This article seeks a new perspective on contemporaries’ evaluations of novelty and tradition by asking how the period’s transformations were perceived by the receivers, rather than the generators, of novelty. In a field dominated by histories of the genesis of new ideas, it tackles the question of how to tell the history of early modern science, a question central to historians of science, by employing the methods of historians of reading and reception.Footnote ³ In particular, it examines the reading and teaching of Galileo’s 1638 Discorsi e dimostrazione matematiche intorno à due nuove scienze.

The Discorsi was Galileo’s final published text, in which he shared key findings on mechanics and local motion. Written as a dialogue in Italian between three interlocutors that takes place over four days, the work is often described as addressing two new sciences. Days 1 and 2 present Galileo’s science of materials, focusing specifically on the resistance of bodies to breakage. Days 3 and 4 contain Galileo’s science of motion and consist of a discussion in Italian of a Latin treatise written by the “Academician” (Galileo), which contains Galileo’s well-known results on local motion, including the fact that all bodies fall at the same speed and that projectiles follow a parabolic path.

The Discorsi occupies a privileged position in the historiographical tradition. The text has been considered a key step in the transition from Scholastic Aristotelian natural philosophy to classical physics because of the mathematical, mechanical, and experimental approach to the study of local motion Galileo advocated in place of Aristotle’s causal, descriptive science.Footnote ⁴ Galileo himself portrayed the Discorsi in this light. He announces at the start of day 3 that he was “bringing forth a very new science on a very old subject,” an allusion to his quantitative approach to the study of motion, a topic central to Aristotelian natural philosophy.Footnote ⁵ In another passage, he explicitly states his intention to set aside Aristotle’s question of the causes underlying such motion to concentrate on quantitative description.Footnote ⁶ Scholarship on the Discorsi has focused primarily on its genesis. The smaller number of studies dedicated to the text’s reception has reinforced its reputation as a key step in the development of modern science by analyzing the reactions of readers interested in the elements of the work associated with the development of classical physics.Footnote ⁷

This piece questions the received view of Galileo’s reception by considering readers of the Discorsi thus far overlooked in the Galilean historiography. Specifically, it examines how professors of natural philosophy at the Jesuit Collegio Romano and University of Pisa incorporated aspects of the Discorsi in their teaching and note-taking.Footnote ⁸ It compares their responses to annotations made in surviving copies of the Discorsi by the Oxford mathematicians and founding members of the Royal Society Seth Ward (1617–89) and Christopher Wren (1632–1723), two readers of the text largely unknown (or overlooked) by Galileo scholars. This diverse group of contemporary readers approached the text using the methods of traditional textual natural philosophy. Their approach and responses challenge the current narrative of Galileo’s reception.

Drawing on recent scholarship, Domenico Bertoloni Meli has argued that readers of Galileo were most interested in the sections of the Discorsi that treated Galileo’s new science of motion (days 3 and 4). In their responses to these sections, Bertoloni Meli claims, readers followed three main approaches. Some readers, including Galileo’s students Evangelista Torricelli (1608–47) and Vincenzo Viviani (1622–1703), concerned themselves with formalizing and extending Galileo’s science of motion in imitation of Archimedes’s work on the equilibrium of the balance. Another group of readers, which included Gianbattista Baliani (1582–1666) and Marin Mersenne (1588–1648), were not convinced of the validity of Galileo’s propositions and questioned his specific empirical claims; they undertook to perform experiments that at times challenged Galileo’s statements and results. Finally, a third group of readers expressed doubts about the specific and general philosophical propositions underlying his science of motion. These readers, who included Honoré Fabri (1607–88), Pierre Le Cazre (b. 1589), and Pierre Gassendi (1592–1655), sought to provide a more solid metaphysical underpinning for a science of motion.Footnote ⁹ Other readers, both inside and outside the university, sought to validate, extend, or modify the findings of the Discorsi. A number of readers, including François Blondel (1618–86) — architect, engineer, and member of the French Academy of Sciences — and the Pisan professors of mathematics Alessandro Marchetti (1633–1714) and Guido Grandi (1671–1742), debated the correctness of Galileo’s findings in day 2 and argued for their priority in correcting and extending his ideas.Footnote ¹⁰ Others, including Galileo’s student Benedetto Castelli (1578–1643) and the Jesuit mathematician Paolo Casati (1617–1707), attempted to apply Galileo’s quantitative approach to the study of motion to the subject of hydrostatics.Footnote ¹¹

The analysis that follows reveals that a significant group of period scholars read Galileo’s Discorsi in ways thus far not recognized in the historiography. They judged the Discorsi as contiguous with, rather than in opposition to, traditional natural philosophy. It may be tempting to dismiss their reactions as anomalous, yet this diverse group includes individuals of Italian, English, Irish, and French origins. They comprise Catholic natural philosophers at the Collegio Romano and the University of Pisa, and Protestant mathematicians at the University of Oxford who made important contributions to the development of the New Science and were members of the Royal Society. That such a diverse group, some supportive of Galileo, others critical or indifferent, approached the Discorsi using similar traditional methods suggests that Galileo’s readers, on the whole, may have employed comparable reading practices and seen the Discorsi as less of a break with past scholarship than the current historiography implies.

Some recent historians of early modern scholarly methods have argued for the continuing relevance of traditional methods of scholarship into the seventeenth and even eighteenth century.Footnote ¹² This article suggests that traditional methods continued to exist alongside and shape the direction of new methods and scholarly production. Moreover, the reading, reception, and appropriation of new methods and conclusions were themselves dependent on older forms of scholarship. In this discussion, the term traditional scholarship will signify an approach to natural philosophy shaped by Scholastic and humanist practices. It builds specifically on the notion of a “bookish” natural philosophy that Ann Blair has ascribed to Renaissance natural philosophy before the Scientific Revolution.Footnote ¹³ According to Blair, Renaissance natural philosophy melded Scholastic and humanist practices in an enterprise that consisted largely of textual criticism. It was an exercise in exegesis that involved the extraction and reusing of material from texts. Its goal was not the discovery of new knowledge but the systematization of an existing body of scholarship, whose parameters were set by the writings of Aristotle and his commentators. Its activities were directed at defining, describing, dividing, ordering, and causally explaining this body of knowledge. In keeping with the Scholastic tradition, the method of determining the truth was the same as the method of discovering it. Both proceeded by means of the quaestio, in which set questions were raised in connection with a given section of Aristotle’s writings and then resolved in reference to the writings of Aristotle and his commentators.

The textual tools and output produced within this tradition included not only the commentaries and Scholastic pedagogical treatises of quaestiones, but also new genres encouraged by humanist pedagogues. Of particular importance to the reading and writing of natural philosophy was the commonplace book, a method of keeping notes encouraged by Desiderius Erasmus, Rodolphus Agricola, and Philip Melanchthon, among others, which drew on ancient and medieval antecedents. Students were instructed to keep notebooks in which they recorded passages from their reading under appropriate headings (commonplaces) for later retrieval and use, notably in their own compositions.Footnote ¹⁴ While this humanist practice is best known for its application to classical and moral subjects, recent scholars have drawn attention to its role in the realm of natural learning through the seventeenth century. Through her study of Jean Bodin’s 1596 Universae Naturae Theatrum, Blair has argued that natural-philosophical writers in the sixteenth and early seventeenth centuries relied on books of natural commonplaces. These natural commonplaces derived from one’s reading and even personal experience and were collected according to heads, following the guidelines set forth by earlier humanist educators for the reading of literature, theology, and other subjects.Footnote ¹⁵ Though the commonplace method was increasingly criticized in the seventeenth century, Richard Yeo has argued for its continuing vitality and its adaptation and transformation, from a tool of memory to one of storage and retrieval; Francis Bacon (1561–1626) and John Locke (1632–1704) were among the authors who relied on and transformed this traditional method.Footnote ¹⁶ Blair’s description of a bookish natural philosophy has enriched the more general terms in which historians of early modern science have compared the textual, exegetical methods associated with Scholastic and humanist approaches with the empirical, quantitative, and mechanical methods of the New Science.Footnote ¹⁷ The former involved the close reading, note-taking, and commenting on authoritative texts with the goal of explicating them. The latter used experiment and mathematics to describe, predict, and (at times) control what happened in nature.

Reading and writing about a text with pen in hand, of course, is a common feature even of modern reading. What sets Galileo’s readers apart from today’s readers is that their reading was carried out with the methods, goals, and content of traditional natural philosophy. Some read using the tools of humanist scholarship (e.g., the commonplace book). Others did not necessarily put their notes into commonplace books but paid specific attention to the aspects of Galileo’s text that touched on the topics and questions of Aristotelian natural philosophy as taught in the early modern university. These were the same topics and questions that likely would have served as the heads of natural-philosophical commonplace books. Finally, others incorporated Galileo’s Discorsi into textual productions characteristic of bookish natural philosophy, including teaching texts on Aristotle and pedagogical dialogues.

The analysis that follows considers three separate case studies that reveal how diverse groups of readers approached the Discorsi using the tools of traditional natural philosophy. The second section, “Jesuit Natural Philosophers Teach the Discorsi: Using New and Old in Tandem,” examines how professors of natural philosophy at the Collegio Romano incorporated Galileo’s empirical measurement of the heaviness of the air in their commentaries on Aristotle. The next section, “Pisa: A Dialogue between Old and New,” discusses Claude Bérigard’s treatment of the Discorsi in successive editions of his Circulus Pisanus; through consideration of the reading notes of Lorenzo Bellini, it argues that Bérigard and others saw old and new in dialogue because they relied on traditional note-taking methods, such as commonplacing. The marginal annotations of Oxford mathematicians Seth Ward and Christopher Wren are considered in the fourth section, “Ward and Wren: Textual Scholarship in the Service of the New Science.” These annotations reveal that Ward and Wren annotated the Discorsi with many of the same concerns and methods as did their counterparts who taught natural philosophy in Italian universities. Finally, the conclusion demonstrates how these findings of Galileo’s readers might reshape current understanding of the Discorsi, its period reception, and Galileo himself.

Jesuit Natural Philosophers Teach the Discorsi: Using New and Old in Tandem

Founded in 1551 by Ignatius Loyola (1491–1556), by the seventeenth century the Collegio Romano stood at the center of a vast international network of Jesuit colleges that aimed to provide a rigorous and orthodox education, offered free of charge. The order’s high standards of scholarship — as well as its commitment to sound and orthodox teaching — were enforced both through an internal system of censorship and through ordinances promulgated with regularity throughout the period.Footnote ¹⁸ This case study inquires into the methods with which these readers approached the Discorsi and the relation they saw between the text and their own scholarly projects. This focused examination of how three obscure Jesuit professors at the Collegio Romano presented one passage from the Discorsi in their natural-philosophical teaching reveals that these professors relied on old and new approaches and conclusions in tandem, using Aristotle and his commentators to evaluate Galileo’s findings and vice versa. That is, these professors not only defy Galileo’s description of them as traditionalists, but they call into question the very binary categorization Galileo offered of his contemporaries. While these particular professors did not go on to engage more extensively with Galileo’s work in subsequent publications, their treatment of the Discorsi in their teaching parallels the way other, more prolific Jesuit authors interacted with texts of the New Science in the period.Footnote ¹⁹

The passage in question is found in day 1 of the Discorsi, in which Galileo describes two procedures for measuring the heaviness of air compared to that of water. Using these methods, Galileo claimed to have determined that water is about 400-times heavier than air.Footnote ²⁰ The responses of the Jesuit readers considered here are similar to those of other Jesuit professors of natural philosophy at the Collegio Romano. In general, these readers focused on specific passages of the Discorsi in which Galileo treated a topic central to their own discussions of Aristotle (e.g., the heaviness of the air, rarefaction and condensation, the question of the void), and they discussed Galileo’s claims, either rejecting or accepting them on the basis of their reading of Aristotle and his commentators. Most scholarship on the reception of the Discorsi has emphasized contemporaries’ interest in days 3 and 4, yet Jesuit natural philosophers drew most heavily on passages in day 1. Only a few individuals mentioned Galileo’s findings on local motion contained in these later days, and those who did so followed the approach found in their discussions of other passages from the Discorsi, folding Galileo’s findings into topics and questions standard in early modern commentaries and teaching texts on Aristotle’s natural-philosophical writings.Footnote ²¹ Galileo’s discussion of the heaviness of the air is thus a suitably representative passage to choose when analyzing the response of Jesuit readers.

Jesuit readers were interested in this passage in the Discorsi because the question of the heaviness of the air had a long history in medieval Scholasticism and even antiquity. Galileo, who himself was educated in natural philosophy at the University of Pisa and was a serious student of Aristotle in his younger days, was familiar with this tradition: in fact, he wrote the Discorsi with an eye toward it. In his description of his two methods for measuring the heaviness of the air, Galileo references this tradition specifically through the comments of his interlocutor Simplicio, who cites Aristotle’s De caelo directly, calling attention to Aristotle’s example of leather pouches, which are found to be heavier when inflated with air than when they are empty.Footnote ²² This example of the inflated pouches, or bags, was commonly cited by Aristotle’s ancient, medieval, and early modern commentators. Aristotle’s ancient commentator Simplicius (ca. 490–ca. 560) of Cilicia discussed the example at length in his own commentary on Aristotle’s De caelo, and later medieval commentators, including Peter of Auvergne (d. 1304), drew on Simplicius’s treatment in their discussions of the heaviness and lightness of the elements.Footnote ²³

The question of the heaviness of air continued to be discussed in detail by later medieval and early modern commentators. In his commentary on book 4 of De caelo, for example, Jean Buridan (ca. 1300–after 1385) poses the question, “Whether air is heavy or light in its own region, or whether it is neither heavy nor light.” Buridan describes the example of the inflated pouches twice in his discussion, both times as an example of Aristotle’s conclusion that air does have heaviness in its region.Footnote ²⁴ Because Buridan argues that air does not have heaviness or lightness in its region, he accounts for Aristotle’s example of the pouches by appealing to the commentary of Ibn Rushd (Averroës, 1126–98), who had argued that the air in the inflated pouches was heavier only because it was more condensed than the outside air.Footnote ²⁵ Albert of Saxony (ca. 1316–90) offered a similar presentation of the question and example as did Buridan. He discusses the pouches in a quaestio on De caelo entitled, “Whether some element in its place is heavy.” He cites the example as evidence of air’s heaviness in its own region but dismissed the evidence, as had Buridan, by appealing to the explanation that its apparent heaviness is only due to its being condensed and compressed within the pouch.Footnote ²⁶

In the commentary on De caelo produced by the Jesuits at Coimbra — published in multiple editions and often cited in textbooks and teaching notes of professors at the Collegio Romano — the example of the pouches was also singled out for discussion. The Coimbra commentary consisted of Aristotle’s Greek text alongside a Latin translation, followed by an explanation and various quaestiones pertinent to the passage in question. The commentary on De caelo was, in turn, followed by a treatise on various problems relating to the four elements. The second of the problems relating to the element air elaborated on the difficulties posed by the pouches. It asks the question, “If pouches filled with wet air are heavier than empty ones, as we admitted above; why do those float on water, [while] the others sink?”Footnote ²⁷ The commentators respond to their question by ignoring the behavior of the empty pouches and arguing that the lightness of the air contained within the pouches filled with the “aqueous water” made the said filled pouches lighter than water, especially given the tendency of the light air to impel itself above water.Footnote ²⁸

Jesuit readers who encountered this passage in Galileo’s Discorsi thus undoubtedly were drawn to it by Galileo’s own explicit references to this textual tradition, one that would have been familiar to them as expositors of Aristotle’s works on natural philosophy. But aspects of Galileo’s description also would have seemed unusual in this context, for Galileo appeared to provide specific details of an actual procedure and a quantitative result obtained by it. The question to consider here is how these readers negotiated these different claims to knowledge, both the textual claims (of Aristotle, his commentators, and even Galileo himself) and Galileo’s more experimental, hands-on, quantitative claim that provided a measure of the air’s heaviness.

In the earliest surviving records of teaching on the subject at the Collegio Romano, Galileo’s measurement was evaluated using textual methods but not afforded demonstrative weight in traditional proofs. That is, Jesuit readers discussed Galileo’s measurement in their Aristotelian commentaries, but they did not include it as part of their proof or demonstration of the air’s heaviness. The lecture notes of Silvestro Mauro (1619–87), shepherded into print in 1658 by one of his students under the title Quaestionum Philosophicarum . . . Libri Tres, serve as an example of such a response. Born in Spoleto, Mauro had studied philosophy and theology at the Collegio Romano from 1639 to 1648.Footnote ²⁹ After teaching first at the Jesuit school at Macerata and then at the Collegio Germanico in Rome, Mauro was appointed a professor at the Collegio Romano, where he taught theology, ethics, and sacred scripture in addition to the three-year philosophy sequence, comprising logic, natural philosophy, and metaphysics.Footnote ³⁰ Mauro remained at the Collegio Romano until his death in 1687, serving both as prefect (1682–84) and then rector (1684–87). In addition to his Quaestionum Philosophicarum . . . Libri Tres, Mauro also published a six-volume paraphrase of Aristotle’s writings (Aristotelis Opera Quae Extant Omnia, 1668) and a three-volume theology course (Opus Theologicum, 1687). In his Quaestionum Philosophicarum . . . Libri Tres, Mauro argues that while fire had the quality of lightness, it was probable that other elements, including air, did not have positive lightness.Footnote ³¹ He then offers a variety of proofs based on Aristotle’s writings and experiences commonly cited by Aristotle and his commentators to establish that air was positively heavy.

An examination of Mauro’s word choice reveals his conception that his argument — the heaviness of the air — is proved via an appeal to generalized experience, textual authority, and logical argument. According to Mauro, it is proved that air has positive heaviness, “because leather bags, as Aristotle remarks in Book 4 of De Caelo, text 30, weigh more inflated than when they are not inflated; therefore the enclosed air in the leather bags adds weight; therefore it is weighty and heavy.” While “Adversaries can respond that our air is heavy, because it is vaporous and contains many aqueous parts,” Mauro asserts that “we find by experience that our air adds heaviness,” and “since other experiences agree, and since we are not able to acquire any experience of that pure air, we ought to say that air is absolutely heavy, even if it is light with respect to earth and to water.”Footnote ³² In this passage, Mauro proves his assertion of the air’s heaviness by reference to textual authority (Aristotle’s De caelo) and appeals to general experience, notably the example of the leather pouches cited by Aristotle and many of his commentators. No reference is made to a specific experimental procedure, nor, aside from Aristotle’s, is a specific experience mentioned. It is Aristotle’s text, affirmed by Mauro’s and others’ “experiences,” that allowed Mauro to claim that the second part of his conclusion (the air’s heaviness) was proven.

Following his demonstration of air’s positive heaviness, however, Mauro departs from this purely textual debate. Moving beyond the examples and textual proofs that characterized his discussion thus far, Mauro follows his demonstration with a reference to Galileo’s procedure, noting that, “At this point, indeed, we may add a means, [derived] from Galileo for weighing the air and for testing what proportion the heaviness of air has to the heaviness of water of the same volume. Take a shallow dish made of glass with a very narrow mouth, and a continuous shell or outer covering.”Footnote ³³ Mauro goes on to describe a procedure that closely resembled that which Galileo had included in his Discorsi. He closes his description of the procedure by noting that, “By this calculation, Galileo held that he discovered that air weighs around four hundred parts less than does water of equal quantity.”Footnote ³⁴

Mauro’s text reveals that he was careful to assign little epistemic value to Galileo’s experiment. While Mauro agreed with Galileo that the air was heavy, he did not incorporate Galileo’s measurement in his proof of its heaviness. Rather, Mauro completed the demonstration by relying on a logical proof filled with textual references and universal experiences commonly reported in other texts. In Mauro’s commentary, then, Galileo’s measurement was merely an addendum to his argument that air was heavy and not light. As the report of an experiment, the procedure was an interesting aside, not suitable for inclusion in a demonstration undergirded by textual evidence. Mauro’s reliance on the Aristotelian-Scholastic commentary tradition to formulate his proof of the air’s heaviness reveals that, for him, traditional textual arguments continued to serve as the foundation for natural-philosophical demonstration. Mauro clearly considered Galileo’s experimental procedure to be epistemologically inferior to that of Aristotle and his commentators. This impression is supported further by the asymmetry underlying Mauro’s proof and presentation of Galileo’s result. In the course of his proof, Mauro responds to the potential objection against Aristotle’s example of the heavy leather pouches filled with air: the pouches are heavy not because air is heavy, but because they are filled with a mixture of pure air and earthly vapors. Though this argument was easily applicable to Galileo’s procedure, Mauro did not address the relationship between them. Galileo’s reported experience and the generalized experience and logical arguments of textual authorities remained separate in Mauro’s account.

In subsequent decades, professors began to integrate Galileo’s experimental results more fully into the traditional curriculum. This may indicate increasing acceptance of experimental evidence as part of natural-philosophical demonstration.Footnote ³⁵ Alternatively, professors may have been more likely to accept and cite the claims and evidence of authors when they were reported in the texts of others.Footnote ³⁶ One indication of such a transformation can be seen in a set of manuscript teaching notes that follow a natural-philosophical course offered in 1660 by Ignatius Tellin (1623–99). Born in Armagh, Tellin joined the Jesuit order in 1642 and taught philosophy, mathematics, and theology in Venice and Rome.Footnote ³⁷ Tellin’s word choice and sentence structure indicate that he may have developed his course using Mauro’s printed textbook as a model.Footnote ³⁸ If so, Tellin perhaps never consulted the Discorsi directly, but judged Galileo’s claims reliable because they were reported by Mauro.

Like Mauro, Tellin claims that fire is positively light and that the rest of the elements and mixtures are heavy. However, in place of a demonstration of the air’s heaviness, Tellin offers an argument for its probable heaviness. In Tellin’s words, “It is probable that they [the other elements and mixtures, aside from fire] do not have positive lightness, but only less heaviness.” Tellin then goes on to list evidence in support of his assertion. For one, he notes that “bodies never rise above those heavier in species unless when an impetus is impressed on them by a heavier one forcing them out.”Footnote ³⁹ As an illustration of this principle, Tellin points to another instance of generalized experience reported in Aristotle’s De caelo, namely the behavior of a pouch filled with air and submerged in water. According to Aristotle, such a pouch will attempt to ascend, but when the water is frozen, the pouch is forced to remain under the frozen water unless it manages to break the ice. Such a scenario, argues Tellin, is analogous to the behavior of air trapped in stones and metals, which would also be inclined to ascend. Tellin claims that more evidence supported his contention of the air’s heaviness. He first points to the same example noted by Mauro and derived from Aristotle’s De caelo of the inflated leather pouches. The increased heaviness of the pouches when inflated “is evidence . . . that simple, unmixed air is heavy and weighty.” Such behavior is analogous to Galileo’s recognition “that the heaviness of water to the heaviness of air is in the proportion of 400 to 1.”

Though Tellin reached the same conclusion as Mauro, the role he assigned to Galileo’s measurement was very different. For one, he included Galileo’s procedure as evidence in support of his claim of the air’s heaviness, unlike Mauro, who had relegated Galileo’s measurement to the status of an addendum. In addition, Tellin’s word choice suggests that he judged Galileo’s recently reported measurement to be on equal footing with the textual examples drawn from Aristotle. Tellin divides the four examples described above into pairs, which he connects by the Latin words “his accredit” (“to these it is added”). He then equates the two members of each pair by the Latin words “sicut” (“just as” or “in the same way as”) and “ita ut” (“in the same way as”). That is, the behaviors of the leather pouches noted by Aristotle are equivalent, in Tellin’s writing, to the general observation of air trapped in stones and Galileo’s specific observation of the heaviness of air compared to water. By thus equating Galileo’s measurement to Aristotle’s examples, Tellin implies that Galileo’s measurement was neither an extraneous example designed merely to illustrate Aristotle’s point, nor endowed with a truth status of lesser or greater value than Aristotle’s textual examples.

By the end of the seventeenth century, some Jesuit authors began privileging evidence from recent experiments over the textual tradition. This is evidenced in the manuscript teaching notes composed by Giovanni Iacopo Panici (1657–1716), who taught natural philosophy at the Collegio Romano from 1698 to 1701. Born in Macerata, Panici joined the Society of Jesus in 1673. While he spent most of his teaching career at the Collegio Romano, where he served at various times as professor of rhetoric, natural philosophy, and theology, he taught canon law from 1700 to 1705 in Germany.Footnote ⁴⁰ Panici’s notes reflect his attention to experiments carried out with inverted tubes of mercury and air pumps, which were themselves inspired by Galileo’s claim in the Discorsi that water could not be pumped by suction to a height of more than eighteen braccia.Footnote ⁴¹ Though much of the debate focused on the nature of the apparently void space above the mercury or in the evacuated vessel of the air pump, various authors, including Torricelli, Robert Boyle (1627–91), and the German Jesuit mathematician Kaspar Schott (1608–66), had argued that the behavior of the mercury (which always came to rest at a determined height) could be explained by the weight of atmospheric air.Footnote ⁴² While earlier Jesuit professors, including Mauro, had discussed these experiments in their natural-philosophical teaching, most separated their discussion of the experiments from that of the air’s heaviness, treating the former in sections of the curriculum that dealt with Aristotle’s Physics and the latter in sections of the curriculum dealing with the terrestrial elements.Footnote ⁴³ Panici, in contrast, included his discussion of the air’s heaviness in the section of the curriculum that dealt with the question of the void.Footnote ⁴⁴

For the purposes of the present article, however, what is of interest is how Panici presented Galileo’s experiment in comparison with his predecessors. Panici begins his discussion of the air’s heaviness by declaring that “the heaviness of the air cannot be explained more appropriately than by comparison with the heaviness of other bodies, whose heaviness is perceived by the senses.” After asserting his preference for quantitative comparison, he refers directly to contemporary experiments, noting that, “If air therefore would be compared with water through a ratio of heaviness, it will have [the ratio] of one to 500, if we believe Galileo; or if we believe Mersenne, Fabri, and others, of one to 1000.”Footnote ⁴⁵

Like his predecessors, Panici addresses the traditional question of the heaviness of the air, but he does so by beginning not with Aristotle but with recent experimental, quantitative measurements of the heaviness of the air. In Panici’s words, the air’s heaviness cannot be explained “more appropriately” than by comparing it quantitatively to the heaviness of other bodies, like water. Furthermore, while Panici does cite Aristotle’s De caelo as confirmation of his supposition that air was, in fact, heavy, he at no point provides a traditional, Scholastic proof of its heaviness.Footnote ⁴⁶ In many ways, Panici seems to have abandoned the bookish tools of traditional natural philosophy and turned to new experimental evidence to answer the long-standing questions derived from the textual tradition.

Yet further examination of Panici’s text reveals that elements of the commentary tradition continued to inform his thinking. He follows the bold statement about the air’s heaviness with a cautionary note, informing his readers that the quantitative results he previously quoted were not universally applicable. The measurements cited by Galileo, Fabri, and Mersenne, “must be understood of common elementary air; for it cannot be denied that some part of air, on account of mixing with vapors and exhalations, would weigh more, and some [part of air], on account of a lesser mixing, would weigh less.”Footnote ⁴⁷ Panici reminds readers that the air around them mixes with vapors and exhalations and, on account of this mixing, sometimes weighs more or less. This draws directly from the commentary tradition, in particular the objections posed in previous texts to the commonplace example of the inflated leather pouch. As Mauro had noted, the greater heaviness of the inflated leather pouch over an empty one could be explained by the mixing of heavy vapors with pure air. While pure air (according to this interpretation) was light, this mixing made it seem heavy. Panici draws on this interpretive tradition, not to discount the heaviness of the air, but to qualify the experimental results he reported. That is, he relies on the textual commentary apparatus of traditional natural philosophy to qualify and comment upon the experimental results of the New Science. In Panici’s text, elements of the New Science and the Aristotelian tradition come together in a new way. Unlike in previous teaching texts, the New Science together with the commentary tradition forms the evidence for Panici’s conclusion regarding the heaviness of the air.

The response of these readers to Galileo’s measurement evinces a general pattern that suggests the increasing importance of a Galilean style of evidence being employed to answer traditional questions established by Aristotle and his commentators. This pattern, however, cannot — and indeed should not — be distilled into a simple narrative of a triumph or adoption of the New Science in the Collegio Romano. Instead, the most important conclusion to be drawn from it is that this process of transformation first and foremost involved a process of appropriation and integration by which new claims and methods were folded into traditional styles of scholarship by means of traditional, bookish methods. Professors were comfortable with and receptive to taking part in this mixing of old and new, even if they were not always in agreement on how it should be done. Some used the old to evaluate the new, others the new to evaluate the old; in other texts, the old and new pointed separately to the same conclusion. The teaching texts of these three readers suggest that — in contrast to Galileo’s own rhetoric — his readers did not view old and new methods and conclusions as opposing and mutually contradictory, but as interchangeable tools applicable to their own scholarly projects, namely an exposition of Aristotle.

Pisa: A Dialogue between Old and New

A similar attitude toward old and new styles of scholarship is evidenced in the publications and notes of two professors at the University of Pisa. While scholars have varied in their portrayals of Pisa, on the whole they depict the Tuscan university as offering a different intellectual atmosphere and attitude toward Galileo (and other novel currents in scholarship) than Jesuit institutions. Some have argued for the declining intellectual rigor and reputation of traditional universities like Pisa in favor of newer institutions, like the Jesuit colleges. Others have pointed to the close association between the university and Galileo’s students and followers in Tuscany during the period, claiming that these individuals promoted a new Galilean-style science within and outside the university. Others have highlighted the conflict-ridden nature of the intellectual community at Pisa, one divided between conservatives eager to maintain the status quo and those who embraced Galilean and atomistic doctrine.Footnote ⁴⁸ Such depictions reveal the intellectual and cultural context in which Galileo’s Discorsi was read, and highlight differences between the university and the Collegio Romano. This article avoids classing readers according to Galileo’s categories of innovator versus traditionalist. Instead, the analysis presented here focuses on the relationship that two professors at Pisa saw between old and new approaches by examining, on the one hand, two editions of a published exposition of Aristotle’s doctrine, and, on the other, a set of surviving reading notes.

In 1643, the French scholar Claude Bérigard (ca. 1590–1663) published a text entitled Circulus Pisanus. It was written as a dialogue between two interlocutors, one of whom was intended to represent Aristotle’s views and the other those of Aristotle’s ancient opponents rolled into one. Bérigard’s text, which clearly appealed to humanist aspirations to recover and revive the works of ancient writers, was intended as a tribute to his teaching at Pisa. Its title alludes to the practice of circular disputations, a type of informal disputation required by Pisan university statutes, in which students and professors seated in a circle debate the material recently presented in lecture.Footnote ⁴⁹ Bérigard had studied natural philosophy and medicine in Aix before being summoned to the Tuscan court in 1626 to serve as a secretary to the Grand Duchess Christina. The following year, at the urging of Christina’s confessor, Bérigard was appointed an extraordinary professor of natural philosophy, and subsequently assigned to the post of ordinary professor, a position he held until 1639 when he moved to Padua.Footnote ⁵⁰ A post at the prestigious University of Padua was clearly a move up for Bérigard, but part of his desire to leave Pisa may have arisen from more personal reasons. In 1632, he had penned the first published critique of Galileo’s 1632 Dialogo. While Bérigard may have written at the instigation of the Medici to diffuse a tense political situation between Florence and Rome, his text permanently soured his relations with the Tuscan intellectual community, many of whom remained ardent supporters of Galileo.Footnote ⁵¹

Like professors at the Collegio Romano, Bérigard integrated sections of Galileo’s Discorsi in his Circulus where they complemented his discussion of Aristotle’s writings on natural philosophy. One such passage is found in his presentation of the question, standard in university classroom teaching and derived from Aristotle’s Physics, as to whether it is possible for a void to be found in nature. In the 1643 edition of his text, an image accompanied Bérigard’s text (fig. 1). Bérigard gave no source for his image, but claimed it had been proposed by “younger writers” as evidence for the existence of a void. These writers argued that a void could be created in nature if a glass vessel, denoted by the letters A and B, was filled with water. The void would be made in the space indicated by BA when the cover, designated by C, was dragged open by force.Footnote ⁵² In the subsequent discussion, Bérigard’s interlocutors discuss the merits of this proposed experiment. To improve the experiment, they propose adding a heavy weight, shown by the letter D in the diagram, to force the cover to remain extended. While they agree that such an experiment would provide the opportunity to test the void, they conclude, in agreement with Aristotle, that a void can never be found in nature. If the experiment were really carried out, they argue, thin bodies would enter through the pores of the contraption, filling the supposed void space with matter.Footnote ⁵³

Figure 1. Bérigard’s device for creating a void. “In Aristotelis lib. de ortu & interitu” in Circulus Pisanus, 1643, page 32. Image courtesy of the University of Glasgow Library, shelfmark: Sp Coll Veitch Eg6-d.15.

Though no source is cited for this image, this argument made by “younger writers” was almost certainly taken from day 1 of Galileo’s Discorsi. In day 1, Galileo describes a very similar device. The set-up of the device was exactly the same (fig. 2). Here a cylinder is first filled with water, closed up, and turned upside down. Weights are added to the bucket until the inner cylinder separated from the water above it. Galileo, however, intended the device as a way of measuring quantitatively nature’s abhorrence of the void, not as a means (necessarily) to create one.

Figure 2. Galileo’s device for measuring the strength of the void. Discorsi, 1638, page 15. This item is reproduced by permission of the Huntington Library, San Marino, California. Shelfmark RB 701317.

Through the characters in his dialogue, Bérigard effectively put this section of the Discorsi into conversation with Aristotle and his ancient interlocutors. Bérigard’s intellectual project was an exposition of Aristotle, an exercise that had long involved the juxtaposition of Aristotle’s and contrary opinions, and the subsequent resolution of the resulting contradictions. Despite Galileo having dismissed the aims and methods of this style of natural philosophy, Berigard saw this section of Galileo’s Discorsi as relevant to this enterprise, an example to be folded in and analyzed because it touched on the very Aristotelian topic of the void.

This point is made more forcefully through examination of the changes made to this passage in the second edition of the Circulus. In the 1661 edition, Bérigard excised the diagram and its description and inserted in its place the claim that “the same must be said of the living silver (mercury), which is said by modern writers to leave a void space in a glass tube, and [they say] that it is made greater with fire having been brought near, and smaller with ice brought near.” Bérigard goes on to cite specific experiments that negated the possibility that the space contains a void: “since gnats fly about in it, sound is heard [in it], according to the witness Kircher, and light is produced [in it], these things demonstrate that a very subtle body is contained in that space . . . evidently very thin substances are dragged through passage-ways of the glass.”Footnote ⁵⁴ In place of Galileo’s device, Bérigard describes the reports of modern writers who claimed that a void can be created in a glass tube filled with mercury, a void that grows greater when the contraption is heated and smaller when it is cooled. He gives little information about how such experiments were carried out, but does provide further details, including that gnats can fly in the space, light can be produced in it, and — citing the experiments of the Jesuit mathematician Gasparo Berti (ca. 1600–43), as reported in Athanasius Kircher’s (1601/02–80) 1650 Musurgia Universalis — that sound is heard in it. These phenomena were evidence that the space above the mercury is not empty but, in fact, contains very thin substances that arrive through passages of the glass, effectively dismissing the new mercury experiments using the same reasoning he had employed to explain Galileo’s device.Footnote ⁵⁵ Bérigard’s response was a rejoinder commonly employed by those contemporaries, including the Jesuits at the Collegio Romano, who believed that nature did not allow a void space.

Bérigard continued comparing established and novel hypotheses in the 1661 edition of his Circulus Pisanus. Though he rejected the vacuist interpretation of the mercury tubes, he accepted both the premise of experimentation and the reported phenomena. He believed, moreover, that both were relevant to his explanation of Aristotle. What is most interesting is that Bérigard edited the passage on Galileo to keep his text abreast with the most up-to-date speculation. This change indicates Berigard’s view that the old and new are in a continually evolving dialogue, one in which the latest experiments should be brought to bear on the discussion. Bérigard’s decision to replace Galileo’s apparatus with a reference to the mercury experiments also reveals his own familiarity with the state of natural-philosophical investigation. Substitution of Galileo’s proposed procedure with a description of the recent mercury experiments was a sound one, because both experiments were understood as being a means of creating a void, thus violating Aristotle’s provision that a natural void was impossible. They were also related because Galileo’s apparatus was the intellectual inspiration for the mercury experiments. The first experiments with inverted tubes filled with liquid were those of Galileo’s student Evangelista Torricelli, who filled such tubes with water following Galileo’s description in his Discorsi. He then turned to filling the tubes with the heavier liquid mercury, whose maximum height in inverted tubes was significantly shorter than that of water.Footnote ⁵⁶ By replacing his description of Galileo’s apparatus with references to these mercury experiments, Bérigard was thus updating his text by reporting on the next generation of experimental attempts to succeed Galileo’s proposal.

Both Bérigard and the three Jesuit professors considered above incorporated material from Galileo’s Discorsi into their texts when the subject matter addressed by Galileo corresponded with a central theme of Aristotelian natural philosophy. This pattern of reception suggests that these readers approached Galileo’s text with the categories and framework of traditional natural philosophy in mind. The extant notes of one of Bérigard’s successors at Pisa offer a glimpse into the reading methods that may have encouraged professors to read Galileo through the lens of their university teaching.

Lorenzo Bellini (1643–1704) taught natural philosophy and anatomy at the University of Pisa in the second half of the seventeenth century. Bellini studied at Pisa under self-proclaimed followers of Galileo, including Alfonso Borelli (1608–79) and Alessandro Marchetti (1633–1714), and he himself achieved wide acclaim during his lifetime for his publications on anatomy, which applied the latest experimental and physicomathematical techniques to explain the structure and function of the kidneys and sense organs. Bellini’s own writings indicate his familiarity with a wide variety of ancient and early modern authors, from Democritus (ca. 460–ca. 370 BCE) and Anaxagoras (ca. 510–428 BCE) to Galileo, Pierre Gassendi (1592–1655), and René Descartes.Footnote ⁵⁷

Bellini’s extant papers, now held at the Biblioteca Laurenziana in Florence, indicate that while he read, discussed, and oftentimes embraced novel hypotheses in his publications, he continued to employ traditional textual practices in his working methods. Specifically, these extant papers contain three different collections of reading notes taken according to the commonplace method, the method of note-taking advocated by humanist pedagogues and applied to the textual enterprise of bookish natural philosophy.Footnote ⁵⁸ Bellini’s commonplace notes follow a slightly different format than that described by Erasmus and other sixteenth-century humanists. Rather than devoting each page to a different topical heading, as earlier humanists had advised, Bellini organized his notes loosely topically and alphabetically. At times Bellini included a heading on each page corresponding to a specific topic, such as “Mixtio” or “Motus” or “Anima,” but the entries on each page (labeled or not) often addressed a variety of topics, all of which began with the same first letter. Thus on the page lacking a heading but whose first entry is “anima” (fig. 3), Bellini took notes on a variety of heads that began with the letter a, from “Aqua,” to “Aer,” to “Anima mundi.”

Figure 3. A page of Bellini’s reading notes, Biblioteca Medicea Laurenziana, MS Ashb. 638.4, 183^r. Image courtesy of the Biblioteca Medicea Laurenziana, Florence.

Moreover, Bellini took notes on these topical headings nonconsecutively. In the same section under the heading “Anima,” Bellini took multiple notes on the topics of aer (air) and aqua (water). He notes, for example, that Aristotle had asserted in book 4 of De caelo that water is heavy. Bellini then turns to the subject of air, indicating both Aristotle’s and Plutarch’s opinions on its qualities. He then turns back to water again, noting various opinions by Empedocles, Strato, and Gassendi.Footnote ⁵⁹ This organization bears some resemblance to the “new method” of commonplacing described by John Locke in the Bibliothèque universelle et historique of 1686, in which Locke relied on an alphabetized index to order his collection of commonplace notes.Footnote ⁶⁰

Bellini’s juxtaposition of ancient writers with Gassendi in his notes on water highlights a more general feature of his commonplace notes, namely his tendency to put old and new sources in dialogue. Just as Mauro, Tellin, Panici, and Bérigard had seen Galileo as relevant to their expositions of Aristotle, Bellini’s reading notes reveal his view that these ancient and modern sources all speak to standard, shared topics of interest. A brief examination of Bellini’s commonplace entry entitled “Motion and Mover[s]” demonstrates more fully this aspect of his reading.Footnote ⁶¹ In his notes, which run for over four pages, Bellini collected the ideas of a diverse group of authors, from Aristotle to Galileo. As was the practice in commonplace books, Bellini jotted down the ideas of different authors, even when their approaches or conclusions are, to modern sensibilities, contradictory. Bellini, for example, described and provided textual references for Aristotle’s distinction between natural and violent motion, as well as Aristotle’s notion that all motion was the result of the action of a mover.Footnote ⁶² Bellini interspersed with these notes devoted to Aristotle’s qualitative approach to motion Galileo’s quantitative rules on the behavior of accelerated and projectile motion.Footnote ⁶³ Similarly he juxtaposed Galileo’s findings on the quantitative rules for accelerated motion with Gassendi’s speculations on the cause of such motion, despite the fact that Galileo argued in his Discorsi that such a query was beyond the scope of his investigation.Footnote ⁶⁴

Bellini’s commonplace notes reveal that one of the reasons why seventeenth-century readers — in contrast to modern scholars — saw Galileo’s Discorsi as in dialogue with traditional natural philosophy was because of the tools they used to read it. The bookish practices of traditional natural philosophy encouraged readers to sift the contents of a text through the standard heads of a commonplace book or traditional natural-philosophical course. Because the goal of such an enterprise was the juxtaposing of authors’ opinions on a standard set of topics, the process encouraged readers to put the texts they read — both those of traditional natural philosophy and those of the New Science — in dialogue. Galileo had claimed at the beginning of day 3 of the Discorsi that he was putting forward a whole new science concerning a very old subject, a reference to the primacy of motion in Aristotle’s writings and to the very different quantitative and experimental approach he himself espoused. The two Pisan professors showed otherwise. Bérigard, by using Galileo to explicate Aristotle, and Bellini, by relying on the traditional textual tool of the commonplace book, put Galileo’s work in dialogue with the very tradition he ostensibly rejected.

Ward and Wren: Textual Scholarship in Service of the New Science

Perhaps it should be anticipated that university professors of natural philosophy, a group portrayed by Galileo (and often modern historians) as of limited intellectual horizons, read the Discorsi through glasses tinted by the methods and aims of traditional textual natural philosophy. The existence of two heavily annotated copies of the Discorsi, one previously unknown, the other overlooked, in the Savilian collection at the University of Oxford’s Bodleian Library suggests otherwise. The first is a copy that will be shown to have been annotated by Seth Ward, founding member of the Royal Society, Savilian professor of astronomy from 1649 to 1660, and later bishop of Salisbury. The second is a copy annotated by Christopher Wren, the architect responsible for the reconstruction of St. Paul’s Cathedral in London following the Great London Fire of 1666, member and president of the early Royal Society, and Savilian professor of astronomy at Oxford from 1661 to 1673. These copies show how two mathematicians who actively participated in and promoted the seventeenth-century New Science similarly brought the tools and concerns of traditional bookish natural philosophy to bear on their readings of the Discorsi.Footnote ⁶⁵

In 1619, Sir Henry Savile (1549–1622) created two Oxford professorships (the Savilian chairs) in astronomy and geometry, and donated his own books to form a library for use by the appointed professors. Later professors added their own volumes to the collection, which now numbers around 1,180 volumes. The Savile collection contains two copies of Galileo’s final published work; the first (shelfmark Bb.13) is a copy of the first edition of the Discorsi, published in Leiden in 1638, while the second (shelfmark A.19) is a copy of the Discorsi contained in the first edition of Galileo’s collected works, his 1655–56 Opere, published in Bologna. Both of the volumes are heavily annotated, with extensive marginalia and notes written on the inside covers and fly leaves, as well as on additional sheets inserted into the books. These volumes are some of the first heavily annotated copies of the Discorsi to have been identified outside of Italy.Footnote ⁶⁶ Wren has been identified as the owner and annotator of the Savile A.19 by J. A. Bennett, on the basis of the book’s physical features (a note on the title page indicates the book was donated by Wren and its spine is monogrammed with the initials “CW”) and the handwriting contained within it.Footnote ⁶⁷ The 1638 volume, one apparently unknown to modern scholars, appears to be annotated by Seth Ward.

Close examination reveals that the annotations in the two volumes are nearly identical. Furthermore, it is clear that those found in the A.19 Wren volume (1655–56 Opere) were copied from those found in the Bb.13 Ward volume. The inserted pages often contain references to page numbers. In the latter edition (fig. 4), these references are all clean, but in the former edition (fig. 5), they are almost without exception crossed out. At one point, the reader of the 1655–56 edition (Wren) accidentally wrote the page number as 137, which corresponds to the 1638 reader’s notes, and subsequently corrected it to 101.

Figure 4. Ward’s page-number references. Savile Bb.13, fly 3^v (detail). Courtesy of the Bodleian Library, University of Oxford.

Figure 5. Wren’s page-number references. Savile A.19, loose slip 2^v between pages 88 and 89 (detail). Courtesy of the Bodleian Library, University of Oxford.

It is the marginal annotations corresponding to these additional sheets that indicate that the annotator of the 1638 copy is Ward. The annotator of the 1638 volume referred readers to these additional sheets with marginal annotations that read, for example, “See the empty page at the beginning of the book for another demonstration.”Footnote ⁶⁸ The corresponding annotations of the 1655–56 edition consistently cite not the additional sheets inserted in the book (which are identical to those found in the 1638 edition), but instead the work of “D. Ward,” a reference that appears to be to Dr. Seth Ward.Footnote ⁶⁹ These annotations suggest that Wren copied his annotations from the 1638 edition, and that the annotations in that earlier edition were written by Seth Ward. In his studies of Wren’s mathematics, Bennett made brief mention of Wren’s annotated copy. He posited on the basis of these annotations that Wren had had access to “some kind of discussion, or perhaps a course conducted by Ward, [which] had centred round the Discorsi.”Footnote ⁷⁰ Comparison with the corresponding annotations of the 1638 edition reveals that the source of Wren’s solutions was most likely Ward’s own annotations. The 1638 edition is thus the “course” or “discussion” that Bennett had foretold in his 1975 article.

Ward’s and Wren’s annotations suggest that they came to the text with multiple goals and read the text in a variety of ways, from working through Galileo’s mathematics to taking note of Galileo’s conclusions. The present section highlights the similarities between Ward’s and Wren’s approaches to the Discorsi and those of Galileo’s Jesuit and Pisan readers, not because Ward and Wren only read the Discorsi through the lens of traditional natural philosophy, but because the fact that they did so in a consistent and thorough way reinforces the argument that multiple readers from different perspectives and backgrounds considered the methods and concerns of traditional textual natural philosophy as suitable for application to Galileo’s text. In the discussion that follows, Ward is named as the reader of Galileo, except in instances in which it is important to note an aspect of Wren’s response that differs from Ward’s.

First, Ward paid close attention to the parts of the Discorsi that treated subjects central to Aristotelian natural philosophy. For example, he noted Galileo’s discussion of such subjects as “the resistance of the void,” “on infinite indivisibles,” and “examples of rarefaction and condensation.”Footnote ⁷¹ He also recorded Galileo’s conclusions regarding these topics, noting Galileo’s opinion that the continuum consists of indivisible atoms, that the velocity of a descending body does not depend on its heaviness, that air is heavy, and that a heavy body in motion differs from one at rest.Footnote ⁷² These topics were central to period expositions of Aristotelian natural philosophy and were from the same sections of the Discorsi that university readers tended to incorporate into their discussions of Aristotle.Footnote ⁷³ Ward indicated his particular attention to this aspect of the Discorsi by including on the inside cover of his copy a more extensive summary of Galileo’s explanation of rarefaction and condensation under the title, “Condensation and rarefaction from the opinion of Galileo.” In this note, copied by Wren in his own exemplar, Ward summarized Galileo’s claim that the two processes could be explained by supposing that bodies were composed of infinite indivisibles.Footnote ⁷⁴

Noting Galileo’s discussion of topics central to the Aristotelian tradition could be seen as inconsequential — active readers, to be sure, would have taken note of Galileo’s main points of discussion — were it not for additional annotations that point to Ward’s interest in another central concern of traditional natural philosophy explicitly set aside by Galileo, namely a search for the causes underlying motion. In day 3, Ward included the marginal note, “The cause of accelerated motion in the descent of heavy bodies.”Footnote ⁷⁵ In the corresponding passage, Galileo’s interlocutor Sagredo briefly mentions some common speculations on the cause of accelerated motion. Salviati quickly interrupts, declaring that such a topic lies outside Galileo’s intended aims to describe motion quantitatively. Ward’s annotation suggests that he read this passage as Galileo’s summary of possible causes of accelerated motion, not as a statement of Galileo’s intent not to treat of this subject. An additional annotation in day 4 confirms that, despite Galileo’s admonition to readers that he rejected the causal physics advocated by Aristotle, Ward read the Discorsi with this concern in mind.

In the relevant passage, Sagredo compares Galileo’s conception of the horizontal and vertical components of the projectile’s parabolic trajectory to Plato’s idea that God had started all planets moving toward the sun from the same point in the universe and later converted their rectilinear motion into a uniform circular one. In the margin of his copy, Ward noted that if the Platonic hypothesis to which Galileo refers is true, it would be necessary “that the Earth and other planets respect some heavenly body (perhaps the sun) as a center in their proper motion (just as our heavy bodies are carried to the Earth as a center) or by a different route some certain thing must be assigned as a cause of accelerated motion.”Footnote ⁷⁶ Whatever Ward’s thoughts were regarding the possible causes of accelerated motion and that of planetary motions, his annotation reveals — contrary to Galileo’s own professed intentions — that he was interested in the causes underlying projectile, accelerated, and planetary motion and that he brought this concern with him as he read the Discorsi. In this sense, Ward’s approach to the Discorsi can be seen to parallel Bellini’s, for both find nothing amiss in reading and annotating Galileo’s quantitative, experimental findings on motion (which were accompanied by Galileo’s decision to reject such a causal study of motion), while simultaneously remaining interested in understanding the causes underlying such motion.

Finally, Ward’s marginal annotations and inserted note sheets reveal his interest in the relationship between the Discorsi and other textual sources. The process of textual citation and attribution was, of course, the very feature of bookish natural philosophy that Galileo criticized in Sarsi in the quotation with which this article began. Many of Ward’s annotations reference the works of other authors, including Christoph Clavius (1538–1612), Bonaventura Cavalieri (1598–1647), and Galileo’s own previous publication on floating bodies.Footnote ⁷⁷ At times, Ward signals Galileo’s relationship to Aristotle through his marginal notes. When Galileo criticizes Aristotle’s opinions on the relative velocities of falling bodies, for example, Ward includes a marginal annotation that reads “Aristotle’s error.”Footnote ⁷⁸ Wren includes a separate annotation, not found in Ward’s text, that reads, “this is characteristic of Aristotle,” in the section of day 1 in which Galileo explains that the coherence of bodies can be explained by nature’s repugnance to the void acting between the minimal particles of bodies.Footnote ⁷⁹ Ward confirmed his interest in Galileo’s relationship to other textual authorities by including a “list of authors cited by Galileo” on the verso side of the errata sheet (fig. 6); Wren copied the list into his own book (fig. 7), but left out the relevant page numbers, perhaps because it would have been too much trouble for him to translate Ward’s page numbers (for the 1638 edition) into the corresponding numbers for his 1656 edition. This list includes Aristotle, Guidobaldo, Euclid, Plato, and Galileo himself. This pattern of annotations reveals that Ward (and subsequently Wren) believed the traditional categories of analysis and agenda of bookish natural philosophy were applicable to Galileo’s text.

Figure 6. Ward’s list of authors cited by Galileo. Bodleian, Savile Bb.13. Table of printing errors (detail). Courtesy of the Bodleian Library, University of Oxford.

Figure 7. Wren’s copy of Ward’s list of authors cited by Galileo. Bodleian, Savile A.19, loose slip 4^r between pages 88 and 89 (detail). Courtesy of the Bodleian Library, University of Oxford.

In addition, that Wren copied Ward’s annotations suggests that the two men read the Discorsi as a pedagogical text. The glossing and commenting on texts and the copying of such explications — via student lecture notes or through marginalia — was an activity central to both Scholastic and humanist educational practice.Footnote ⁸⁰ While this teaching is often associated with the texts of classical authors, the use of such a technical mathematical text in early modern pedagogy is not unknown. Owen Gingerich has shown that many of Nicolaus Copernicus’s readers responded similarly — using marginalia and copying marginalia from one copy to another — as they responded to the first two editions of his De Revolutionibus, first published in 1543.Footnote ⁸¹ Wren first joined the scholarly community at Oxford in 1650 as a gentleman commoner at Wadham College, where Ward was then living.Footnote ⁸² If Wren purchased his copy of Galileo’s Opere when it was published in 1656, it is possible that he copied the annotations in Ward’s 1638 copy as part of his introduction to and training in the community there. It is not surprising, of course, that Wren would have been familiar with the Discorsi and even owned and annotated his own copy of the text as part of his introductory training. What makes Wren’s use of the Discorsi in keeping with the methods of bookish natural philosophy is the fact that the transmission took place through the copying of his teacher’s extensive marginalia, which treated not only Galileo’s main ideas and mathematics, but explored multiple aspects of the text, from its mathematics to its reliance on other textual authorities.

Conclusions

The traces of reading examined here suggest that some seventeenth-century readers read Galileo’s Discorsi — a canonical text in the history of early modern science, one usually celebrated for its embrace of quantification and experimentation — using the tools and categories of traditional scholarship. These included the note-taking and commonplacing methods and the attention to textual authorities, standard topics, and causal explanation associated with Scholastic and humanist approaches to natural philosophy. The approach was consistent across geographic, religious, and disciplinary boundaries. It was used by Jesuit natural philosophers based in Rome but who came from across Europe (Mauro from Spoleto, Tellin from Armaugh, and Panici from Macerata); the native Florentine Bellini, known primarily for his innovative work in anatomy; the French Bérigard interested in the writings of the pre-Socratics; and Ward and Wren, two Oxford scholars who made important contributions to mathematics and English experimental philosophy. That this diverse group of readers approached the Discorsi using a common set of methods suggests that this textual approach to the Discorsi was widespread. It reflected scholarly practices shared across early modern Europe, practices that shaped the way the Discorsi was read and — given Galileo’s participation in the community — the way it was written.

Taking Galileo at his word, one might be inclined to dismiss this textual response to his Discorsi as a sign that many of Galileo’s readers radically misinterpreted his aims and methods. Galileo is well known for his outspoken criticism of the textual methods of his contemporaries. The type of response to Galileo’s text analyzed in this article — marginal annotations, note-taking, commonplacing, putting Galileo as a textual authority in dialogue with other writers — seems to be exactly the type of response Galileo hoped to avoid in his own scholarly practices, and that he encouraged his readers to abandon as well. Under this interpretation, the readers who followed such practices may be the very readers for whom Galileo expressly did not write, readers whose reactions modern scholars should dismiss because Galileo himself claims he would do the same. It might be tempting, therefore, to argue that the readers considered above misinterpreted Galileo because they were so steeped in the textual tradition he came to eschew.

Such a line of reasoning, however, ignores the most valuable insight that a study of reception can bring. Theorists of reader reception have argued that the interpretation of an author’s ideas is not fixed on the printed page (or other medium) but arises (and is continually in flux) in the act of reading itself. Because a text’s meaning is malleable, the notion of misinterpretations and uncorrupted transmission is irrelevant.Footnote ⁸³ Hans Robert Jauss’s notion of a horizon of expectations — of expectations about genre, knowledge claims, and approaches — shared by authors and their readers enters in here.Footnote ⁸⁴ This notion privileges the interpretations of texts provided by period readers, readers infinitely more well versed than modern historians in the intellectual, social, and cultural context in which the author operated. In the case of the Discorsi, that so many readers of Galileo from diverse backgrounds, institutional affiliations, and disciplinary traditions thought the tools of traditional textual scholarship were appropriate ones for applying to his text suggests that, despite his rhetoric, Galileo retained strong ties to the world of traditional scholarship. That is, these readers who approached Galileo’s text using traditional textual methods did not misread Galileo by evaluating the Discorsi through their interpretations of Aristotle or through the traditional topics of natural philosophy. Rather, they were picking up on elements of the text that modern scholars have not been trained to see.

Galileo’s surviving papers and books support such a view. Galileo himself was an avid student of Aristotle and Aristotelian natural philosophy (at least in his early days).Footnote ⁸⁵ He annotated his own books and those of his contemporaries, and he relied on these annotations in his own compositions.Footnote ⁸⁶ Furthermore, as scholars of Galileo’s library have emphasized, despite Galileo’s and his students’ insistence to the contrary, he owned and worked with a very large library filled with ancient, medieval, and contemporary works.Footnote ⁸⁷ While Galileo thus may have hoped that modern scholars would discount this textual approach to his texts as unimportant, the fact remains that period readers of diverse backgrounds and interests thought his Discorsi could be studied using traditional methods. To make sense of their response, it is necessary to go beyond Galileo’s rhetoric — his ostensible commitment to experimentation, quantification, sensory experience, instruments, and new techniques of visual representation — to see how he himself combined new and old. Such an approach is not new to Galileo studies — many previous Galileo scholars have engaged in just such an enterprise — but the notion that traditional methods shaped not only the genesis of the Discorsi, but also its fortuna and contributions to later developments, is.Footnote ⁸⁸

Galileo scholar Stillman Drake once described the Discorsi as “Galileo’s last and scientifically most enduring work . . . a book on physics that opened the road for Newton’s immortal Mathematical Principles of Natural Philosophy.”Footnote ⁸⁹ The examination here does not negate this assessment of the Discorsi so much as it provides a window into how and why the text came to play such a pivotal role. To assert that seventeenth-century readers across Europe read the Discorsi using the tools of bookish natural philosophy shows how traditional methods facilitated the dissemination and understanding of texts of the New Science. These findings confirm the conclusions of scholars who have argued for the continuing relevance of the textual tradition to seventeenth-century scholarship. In fact, they go beyond them to show that it is not only that the two cultures of humanism and science “coexisted and often collaborated,” but that, in many ways, the dissemination and transformative power of the latter depended on the tools and methods of the former.Footnote ⁹⁰ As narratives of early modern science continue to be reassessed, reformulated, and rewritten, one of the most pressing tasks that awaits is the study of the reception of key texts and ideas in the period. Reading the Discorsi through the eyes of contemporary readers provides a glimpse — perhaps the closest modern scholars will ever get — into what it meant to live through and experience the transformations in early modern science once termed the Scientific Revolution.