Friendship in pre-modern Europe was conceived of as far more than an affectionate relationship between emotionally compatible individuals. From ancient Greece to the eighteenth century, it was understood in the contexts of, variously, social obligation, religious and political bonds, or universal harmony. Views changed over time but always accorded the exterior or ‘public’ side of friendship an ethical role inseparable from the interior or personal. This discourse affected, in complex ways, the cultivation, practice and communicative strategies of individuals in their actual friendships. Decades of scholarship have now given us a very full picture of the discourse of ideal friendship. More recently, quantitative and network–structural studies have begun to examine the networks created by historical friendships, applying methods developed in the social sciences. This volume addresses the critical interaction between the two, demonstrating through a series of case studies the ways in which the discourse of friendship affected practice and network formation. It also exemplifies the progress within historical friendship studies from earlier attempts to isolate supposedly ‘genuine’ friendships (taken to be purely affectionate, and often described as modern-type friendships) from the supposedly meaningless rhetorical commonplaces of eternal, universal or perfect friendship found in the sources. The studies collected here illustrate the complex mutual interactions between a meaningful discourse of ideal friendship and the practices of friendship which it shaped.

The volume is divided into three sections, on individual friendships, networks of friends, and friendship in political and international relations. However, the editors identify as a unifying theme an important and often overlooked aspect of pre-modern friendship, what Sarah Rolfe Prodan defines in the introduction as the ‘geometric nature’ of friendship, where individual relationships were conceived as ‘triangulated’ with a third element or actor such as the divine or a just political end (p. 17). This ‘phantom protagonist’ evidences the ethical expectations attendant on friendship and explains how it was deployed as a motivating force creative of real obligations. As one would expect in a collected volume, this theme is more prominent in some contributions than others. It is central to Malina Stefanovska's study of Louis de Pontis' Mémoires and to Francesco Ciabattoni's contribution on Dante, both in the first section, each showing, in different ways, how the ‘third protagonist’ of Christian faith became the prism through which real friendships were understood and accorded meaning, which in turn affected ideas about friendship. Another theme which recurs in the volume is the inextricable interweaving of affection and utility apparent in all the friendships studied, a point made emphatically in Adriana Benzaquén's study of John Locke which opens the volume, demonstrating that sentiment and instrumentality were never seen as incompatible in true friendship. The subsequent contributions all consider to some degree the mixed nature of friendships, and also the modern language of public and private, instrumental and affective, personal and official, used to describe them. The cumulative effect of this is to underline the inadequacy of such concepts to describe these socially embedded relationships. In this way the volume offers an important corrective to many traditional assumptions about the nature of friendship.

The four essays in the networks section deal not with structural analyses of networks but with the use of friendship discourses to regulate and affect actions through the invocation and manipulation of shared ethical concepts. Steven Baker's analysis of Petrarch's invocation of friendship as a ‘political tool’ (p. 149) also shows how Petrarch's models of political friendship correspond to those derived by contemporary social scientists from Aristotle. Sally Hickson describes the formation around the Mantuan court of Francesco II Gonzaga, who suffered from syphilis, of a patronage network of fellow sufferers whose common experience of the disease and shared humanist intellectual interests created a new form of social network. Two papers that sit particularly well together are Brian Sandberg's on French warrior nobles in the wars of religion and Jean Bernier's on Pierre Bayle. Both demonstrate the importance of friendship in the context of confessional conflict, and show how the ideals of brotherhood in arms and of toleration in the military and intellectual spheres, respectively, were mediated, crucially through the experiences of friendship.

The final section shows how experiences of friendship, understood and internalised through discourses of ideal friendship, in turn fed back into new models explaining new economic and political realities. Paolo Broggio describes a re-theorising of friendship as ‘an instrument of social cohesion’ (p. 223, translating Bodin) in the Counter Reformation, an unequal bond whose ‘individualization’ served to reinforce vertical hierarchical ties, in stark contrast to emerging and now more familiar ideas of private friendships traceable to Montaigne. Hyun-Ah Kim identifies friendship as the key to Matteo Ricci's acceptance by Confucian scholars, which Ricci saw as necessary to his mission. Ricci's writings on friendship in Chinese provided the point of ethical contact which permitted inter-faith friendship (distinguished here from inter-faith discourse) and led to a genuine humanist intercourse across a cultural and theological gulf. Finally, David Harris Sacks traces the view, culminating with Richard Hakluyt, that the disparities of resources across the world which made commercial intercourse possible and necessary were divinely instituted to engender friendships through trade. This in turn promoted global unity through the spread of Christianity, thereby incorporating new disruptive forces of colonisation and economic exploitation in a harmonious model, based on the traditional theory of friendship as the principal bond uniting humankind.

This volume does not set out to offer social–structural analyses of friendship networks. Rather, it demonstrates the very specific ways in which the discourse of friendship directly affected practice – choices of friends, network construction and political behaviours – and how these in turn fed back into changing theories of a phenomenon which was, for pre-modern Europeans, a subject not for psychology but for political science.