At the beginning of the seventeenth century, the Scottish polymath Duncan Liddel (1561–1613), professor at several Lutheran universities of northern Germany, relied on the Italian philosopher and physician Julius Caesar Scaliger's (1484–1558) Exotericae Exercitationes (1557), which he praised highly, to argue, in his Ars Medica (1608), that neither previous forms nor qualities remain in the mixture. Once a very popular book (reprinted ten times from 1576 to 1665), Exotericae Exercitationes has recently been rediscovered by historians of early modern science, who acknowledge, among other topics, the fact that Scaliger's theory of mixtures likely paved the way for the rise of early modern corpuscularianism. Exotericae Exercitationes was among the books that Liddel brought to Scotland when he returned to his native Aberdeen and which he bequeathed, together with his library, to the Marischal College (nowadays preserved at the University of Aberdeen Library). The two books under review here, covering different facets of this history, are instrumental to understanding the complex and multidimensional processes through which the circulation of ideas, individuals and models of scholarship shaped the emergence of early modern science, as well as the institutional and social networks that made such cultural exchanges possible.

Duncan Liddel (1561–1613): Networks of Polymathy and the Northern European Renaissance, edited by Pietro Daniel Omodeo in collaboration with Karin Friedrich, offers a collection of studies on the life, scientific works and scholarly networks of Duncan Liddel and his time. Despite being relatively unknown to historiography until the publication of this book, Liddel was a famous professor of mathematics and medicine during his lifetime. Born into a family of modest means, Liddel benefited from the network of patronage relationships and institutions that tied northern Germany, the Baltic area and the British Isles, to study and teach at Frankfurt an der Oder, Rostock and Helmstedt. There, he was deeply influenced by Philipp Melanchthon's humanistic and Reformed values, a legacy which, as Pietro Daniel Omodeo stresses, ‘fostered a special scientific ethos marked by anti-dogmatism and politeness’ (p. 11). Furthermore, Liddel was a polymath, with intense scientific interests in different areas, including mathematics, philosophy, medicine and theology.

Liddel thus offers historians an exemplary case to study the personal, social, scientific and institutional facets of a scientific life in the making in early modern Europe. This book entirely does justice to this multidimensional approach. It opens with an illuminating discussion of the humanistic networks of the northern European Renaissance by Omodeo, which presents the framework of networks and institutions in which Liddel's career evolved (Chapter 1). This chapter, together with the contextualized analysis of life and work of Liddel, also by Omodeo (Chapter 3), is instrumental to understanding not only the fascinating life of Liddel, but also the complex dynamics (geographical, social and institutional) involved in the process of making a scholarly career in early modern Europe. In order to obtain a comprehensive understanding of this process, in his text eloquently entitled ‘Confabulatory life’, Mordechai Feingold argues that it is crucial to integrate the intangible dimension of learned conversation that gathered members of the Republic of Letters (Chapter 2). Feingold makes his point by demonstrating the implications that study and travel abroad, together with the maintenance of correspondence networks, had for British science in Liddel's times, and one can certainly further expand Feingold's argument to other European cases. The importance of intellectual interchanges between the British Isles and continental Europe is corroborated with respect to Scotland by Duncan Cockburn's contribution on the relationship between Liddel and the University of Aberdeen and his enduring legacy in Scotland (Chapter 9).

A crucial feature of Liddel's life and career was his remarkable polymathy. John Henry, in a text devoted to ‘a pragmatic aspect of polymathy’ (Chapter 4), argues convincingly that Liddel's profusion of areas of activity and interest was to a great extent the result of necessity. Unable to obtain a proper income and perhaps a public reputation as a mathematician, he coupled mathematics with a career as physician and professor of medicine. In those areas, he undertook significant scientific work, teaching, publishing and not rarely getting involved in scientific controversies. This volume includes a group of contributions that offer insightful analyses of Liddel's philosophical and scientific thought based on some of those controversies. Jonathan Regier focuses on Liddel's views on the notion of ‘natural light’ and its relationship with the status and hierarchy of logic, mathematics and philosophy in the context of his dispute with the University of Helmstedt's professor of theology Daniel Hofmann (Chapter 5). Laura Di Giammatteo analyses the debate between Liddel and Jakob Horst, a professor of medicine at the same university, on Paracelsism and on Melanchthonian-inspired Galenism, which played a crucial role in the shaping of Liddel's medical philosophy, namely in his criticism of Paracelsian philosophy (Chapter 6). Pietro Daniel Omodeo and Jonathan Regier return to the celebrated controversy over the authorship of the geo-heliocentric system of Tycho Brahe in which Liddel found himself involved. Their study, besides offering a detailed reconstruction of the controversy and the role of Liddel in it, illuminates his astronomical and philosophical conceptions. In addition, Omodeo and Regier publish for the first time the letter that Liddel addressed to Tycho in the year 1600, a critical document in this process (Chapter 10).

These controversies occurred within the institutional framework of universities, and particularly that of the University of Helmstedt. They not only implied different views on several scientific subjects, but also consubstantiated opposite factions within the university and scholarly community. Richard Kirwan devotes an article to the politic dimension of academic network and identifies two parties gathering in Helmstedt, on the one side the philosophers, to which Liddel belonged, and on the other the theologians, where one can find Hofmann, among Liddel's other opponents (Chapter 7). Elizabeth Harding analyses the domestic dimension and shows persuasively that social, political and professional identities were forged at professional homes through home-styling and familiar behaviour (Chapter 8).

Additionally, this volume includes the publication of new sources, namely the above-mentioned letter of Liddel to Brahe, with a translation by Omodeo and Regier and the document's transcription by Miguel Ángel Granada and Louis Mathias Berger (Chapter 10), and Liddel's eulogy of mathematics, analysed and transcribed by Omodeo (Chapter 11). The volume finishes with a deep reconstruction and analysis of Liddel's academic library, based on the ongoing project of studying and cataloguing Liddel's books preserved in the Aberdeen University Library, by Jane Pirie (Chapter 12), and a comprehensive list of Liddel's published and unpublished works by Sabine Bertram (Chapter 13).

Different in nature and scope is Kuni Sakamoto's Julius Caesar Scaliger, Renaissance Reformer of Aristotelianism. Scaliger was a famous natural philosopher and physician graduated from the University of Padua and a self-proclaimed Aristotelian. His natural philosophy has been subject to a series of specialized studies in recent decades, with a special emphasis on Scaliger's role in the emergence of early modern corpuscularianism. Yet a comprehensive understanding of Scaliger's natural philosophy has so far been lacking. This book undoubtedly fills that gap.

Sakamoto offers a consistent interpretation of Scaliger's thought based upon his influential Exotericae Exercitationes. Rather than take Exercitationes as the host of a multitude of disconnected theories, Sakamoto demonstrates that there is a coherent and well-articulated system of ideas permeating this massive book. Instrumental in Scaliger's philosophy is the relationship established between God and created beings. Sakamoto starts by revealing Scaliger's effort to demonstrate that Aristotle endorsed a creation theory compatible with Christian belief in the creatio ex nihilo and with the doctrine of the Trinity (Chapter 1). While analysing the Scaligerian conception of how God's power operates, Sakamoto focuses on Scaliger's rejection of the theory of a world-soul put forward by Cardano and others (Chapter 2) and argues that, according Scaliger, the order and unity of the world (a perfect universe) are granted by a hierarchy of substantial forms (Chapter 3). After a detailed discussion of the core ideas underlying Scaliger's philosophy, Sakamoto proceeds to analyse how they operate in practice, by focusing on four central subjects: the conception of void and place (Chapter 4), celestial intelligences (Chapter 5), the theory of generation of living beings (Chapter 6) and the theory of mixtures (Chapter 7).

Scaliger put forward, therefore, a Christianized version of Aristotelianism, which, according to Sakamoto, stemmed from his aversion to the materialistic and secularized understanding of Aristotelian philosophy as it was carried out by his philosophy professors at Padua and other peripatetics of his time, such as Cardano. Against this tendency, Scaliger wished to propel a more religiously centred approach to Aristotelian philosophy inspired by Scotist theology. Sakamoto offers, thus, not only the first comprehensive account of Scaliger's philosophy, but also a contextualized one, which contributes most to a new approach to early modern Aristotelianism, and particularly to so-called ‘Paduan Aristotelianism’.

Despite their differences, these two books offer penetrating and novel insights into the complex processes of the transfer, appropriation and creation of knowledge in early modern Europe. Both stress the importance of looking into less studied characters, once regarded as minor figures, against their institutional and social background in order to elaborate a more complex and accurate understanding of the origins of modern science in the Renaissance and early modern Europe. They are highly recommended for historians of early modern science and all those who are interested in Renaissance and early modern intellectual history, philosophy and institutional history.