Christoph Sander

This essay investigates the reception of William Gilbert’s foundational work on magnetism, De Magnete, through a comprehensive analysis of extant copies of its early modern printed editions (1600, 1628, 1629, 1633). By employing a hybrid methodology combining quantitative and qualitative approaches to readers’ annotations, this study charts patterns of engagement with Gilbert’s text across diverse contexts and intellectual traditions. While celebrated for its experimental innovations and practical applications in navigation, it also elicited cosmological and humanist interests. Statistical analyses of readers’ marks demonstrate a skewed distribution of engagement, with the majority of annotations concentrated in a small fraction of extant copies. This study moreover contributes to the historiography of early modern science by illustrating the methodological potential of combining large-scale digital datasets with close textual analysis, advocating for more systematic, collaborative approaches to the history of reading and book culture. In addition, a near-complete census of copies of De magnete is provided.

Since Antiquity, scholars have sought to explain the cause of agnetic ‘attraction’ through diverse theories, which raised questions as to whether the magnet attracts iron or vice versa, or if both entities play equal roles. Aristotle himself avoided the notorious question of how magnetic attraction works: his commentators and critics made good for this lacuna. Medieval theories predominantly posited that iron moved towards the magnet for teleological reasons. Medical and alchemical authors in turn emphasized the magnet’s active attraction of iron, while only a minority believed in the iron’s active attraction of the stone. The seventeenth century saw William Gilbert establish an account of reciprocal attraction between the iron and the magnet. These causal representations, rather than being empirically grounded, were often rooted in natural-philosophical or metaphysical assumptions, especially Aristotle’s causal principle of motion. A fierce controversy about the ‘correct’ account of the causal roles in magnetic attraction grounded, prepared and partly overshadowed the debates on how to explain magnetism. This article will shed light on this little-known controversy. It offers a more balanced account of the tacit and salient impact of Aristotelian natural philosophy by providing a framework that enabled different theories to contradict each other – until even this framework dissolved during the seventeenth century.

Already in Antiquity, Galen linked magnetic attraction, by way of an analogy, to the idea that animal parts are able to attract their own ‘specific quality’. For example, a kidney attracts urine just like the magnet attracts iron. In the Middle Ages, Averroes argued that foodstuff and iron possess a specific disposition which allows them to move themselves towards the body and a magnet respectively. Thus, the concepts of ‘specific attraction’ and ‘dispositional selfmovement’ were regarded as crucial to understanding the powers of both a magnet and a living body. Particularly in the early modern period, these concepts were spelled out differently by Aristotelians, Galenists and Paracelsians. During this period, the magnetism-nutrition analogy was also transformed into a vitalist principle in order to explain magnetic attraction itself. Natural philosophers such as Gerolamo Cardano suggested that a magnet, being alive in some way, seeks out iron as its foodstuff - a popular idea among alchemists as well. This paper aims to trace the complicated history of two intertwined concepts, ‘nutrition’ and ‘magnetism’, which were closely related in pre-modern times but appear to be unrelated from a modern perspective. By uncovering the historical origin(s) of this relation, its rationale, its subsequent transformation and its dissolution, the historical concept of ‘nutrition’ will come into sharper view from the perspective of the history of ideas. At the same time, from the perspective of the philosophy of science, this historical study presents a test case scenario for discussing the importance of metaphors and analogies in the formation of scientific theory.

Since antiquity, sources report that garlic deprives a magnet of its power of attraction. Although in later centuries some authors disproved or questioned this effect by experience or trial, several, if not the majority of, writers referred to garlic and magnets as “enemies” until well into the seventeenth century. It will be argued that the probable textual origin of the “garlic effect” is a corrupt or ambiguous passage in Pliny’s Natural History, reading “al(l)ium” (garlic) instead of “aliud” (another) in one passage. With a focus on the early-modern period, it will be elucidated why so many authors did not doubt this physical effect, and some even presented causal explanations for it. It shall be emphasized, moreover, that magnetic attraction, and thereby also the garlic effect, was used as an important example or analogy since antiquity. This illustrative or explanatory use of analogies drawn from the garlic–magnet antipathy certainly goes some way towards explaining the longevity of this odd relation between the two substances.

Johannes de Sacroboscos (c. 1195–c. 1256) De sphaera, eine Einführung in die Kosmologie aus dem 13. Jahrhundert, war mit über 320 Drucken das am häufigsten edierte, kommentierte oder adaptierte astronomisch-kosmologische Handbuch der Frühen Neuzeit. Während die Rezeption und Verbreitung dieses Werkes im 16. und 17. Jahrhundert bereits vielfach untersucht wurden ist bisher übersehen worden, dass diese vermeintlich unproblematischen Sphaera-Textbücher auch vielfach Gegenstand der katholischen Zensur wurden, obwohl sie gerade eine Kosmologie enthielten, die Katholiken als Bollwerk gegen den aufkommenden Kopernikanismus betrachteten. Vorliegender Aufsatz untersucht erstmals die Dynamik und Motive der zahlreichen präventiven und posthumen Zensuren der römischen und iberischen Index- und Zensurorgane mit Bezug auf diesen Kosmologietraktat. Von protestantischen Autoren verfasste Kommentare zur Sphaera waren zwar prinzipiell verdächtig, wurden aber selten pauschal verboten. Vielmehr wurden sie aufgrund ihres wissenschaftlichen Wertes meist genehmigt, nachdem geringfügige, theologiebezogene Expurgationen durchgeführt worden waren. Der Kommentar (1550) des katholischen Autors Mauro da Firenze (1493–1556) wurde hingegen wiederholt und prinzipiell verboten, weil er theologisch bedenkliche Gedanken enthielt. Die hier präsentierte Fallstudie soll zum einen die Wissensdynamik der frühneuzeitlichen Sphaera-Tradition aus einem neuen Blickwinkel beleuchten, und zwar dem der Buchzensur. Zum anderen gewährt ein buchbezogener Längsschnitt Einblicke in die Ideologie und Praktiken der katholischen Buchzensur, wodurch auch die bekanntermaßen problematische Beziehung von Wissen und Religion in der vormodernen Zeit im Lichte einer Konfessionalisierung der Wissenschaften erscheint.

In 1513, the Fifth Council of the Lateran significantly impacted on early-modern Christian philosophy. As is well known, the papal bull Apostolici regiminis condemned certain philosophical doctrines contradicting the personal immortality of the soul. Moreover,the bull prohibited to defend the notion of a double truth in philosophical disputations and urged universities to meet the prescriptions of this decree. This article will shed light on how thispapal intervention in the practice of schooling was met at the early Jesuit college in Rome and the role of Diego de Ledesma, the college’s educational designer, in implementing the bull’s concerns.

In his short treatise De divinatione per somnum (463b12-15), Aristotle claims that dreams, though not sent by a god, are nonetheless “demonic” because “nature is demonic.” This statement has puzzled Aristotle’s commentators since the Middle Ages, being interpreted in a variety of ways even today. The present article traces interpretations of the passage from the twelfth century, when the work was translated into Latin for the first time, until the seventeenth century, when Aristotle’s works were re-translated by the humanists. The aim of the study is to reconstruct how scholars over the course of 500 years dealt with the meaning of the expression “demonic.” The article takes into account not only commentaries on Aristotle, but also several translations of Aristotle’s work, different manuscripts of the work, and hand-written glosses in incunabula. In this way — taking a longue-durée-perspective — the study aims to reveal hermeneutical currents in dealing with Aristotle’s pagan and naturalist theory of dreams within a Christian context which presupposed God as a possible cause of dreams.

Early-modern Jesuit universities did not offer studies in medicine, and from 1586 onwards, the Jesuit Ratio studiorum prohibited digressions on medical topics in the Aristotelian curriculum. However, some sixteenth-century Jesuit text books used in philosophy classes provided detailed accounts on physiological issues such as sense perception and its organic location as discussed in Aristotle’s De anima II, 7–11. This seeming contradiction needs to be explained. In this paper, I focus on the interst in medical topics manifested in a commentary by the Jesuits of Coimbra. Admittedly, the Coimbra commentary constituted an exception, as the Jesuit college that produced it was integrated in a royal university which had a strong interest in educating physicians. It will be claimed that the exclusion of medicine at Jesuit universities and colleges had its origin in rather incidental events in the course of the foundation of the first Jesuit university in Sicily. There, the lay professors of law and medicine intended to avoid subordination to the Jesuits and thereby provoked a conflict which finally led the Jesuit administration to refrain from including faculties of medicine and law in Jesuit universities. Towards the end of the sixteenth century, a veritable Jesuit animosity towards medicine emerged for philosophical and pedagogical reasons. This development reflects educational concerns within the Society as well as the role of commentaries on Aristotle for early-modern learning.


William Gilbert’s work, De magnete (1600), often is referred to as the first monographic study on magnetism in the early-modern period. Recently, however, it has been argued that the Jesuit, Leonardo Garzoni, wrote an experimental study on the subject twenty years earlier and that his research influenced particularly the work of Giambattista Della Porta and Paolo Sarpi,two important protagonists in the history of studies in magnetism. However, to date, Garzoni’s authorship of an anonymous treatise in manuscript, located at the Biblioteca Ambrosiana in Milan, and taken to bear witness to his research, has been based only on circumstantial evidence. This article outlines the identification of two further manuscript copies of this treatise, which have not been studied so far. It shall be argued that the evidence contained in these manuscripts corroborates the assumption that Garzoni indeed is the author of the work that was transmitted anonymously. Moreover, it can be shown that the work was completed and prepared for print later on. These findings also allow us to argue more conclusively that Paolo Sarpi knew Garzoni’s work and passed it to Giambattista Della Porta, who bequethed his copy to the Accademia dei Lincei and thereby made it available to some of the academy’s most important members, Nicolas Claude Fabri de Peiresc and Cassiano Dal Pozzo. Finally, the dynamics of this textual transmission provide insights into how scholars approached the study of ‘magnetism’ in the early-modern period.

Benet Perera started his philosophical career with lecturing philosophy at the Jesuit college in Rome in 1558. Although numerous documents reveal that his lectures were highly appreciated by his listeners, it seems that around the year 1564 Perera’s teachings were criticized by two of his colleagues at Rome, Diego de Ledesma and Achille Gagliardi. They feared Perera would give too much value to the Arab philosopher Averroes and that Perera’s method of teaching would pose a danger to Christian doctrines by raising doubts whether those pious doctrines can be demonstrated within the framework of an Aristotelian philosophy. This article will shed light on the background of this affair by analyzing the questions of how Perera might have provoked the criticism and why his accusers were so keen on putting forward an investigation against Perera. It will become clear that Perera had rather philosophical motives for his method of teaching, whereas especially Ledesma had an explicitly pedagogical rationale for his criticism. By sketching this particular affair this article will also deliver an insight into early Jesuit efforts for and against censorship in teaching philosophy.