Does the concept of natural rights have roots, logical and historical, in the concept of natural law? Our answer is, ‘it depends’. By this, we mean that some conceptions across Western history do not in fact allow for the derivation of natural rights in the subjective sense. In contrast, others are conceived such that natural rights follow logically therefrom. Our premise is that talking about ‘natural law’ in the singular – at least in the period from Roman times to sixteenth-century – represents a distortion of on-the-ground realities.

Francisco de Vitoria (1483–1546) was among the preeminent theologians of his day and his two texts, De Indis and De Iure Belli, mark the start of a vitally important transition in the Christian just war tradition as it exited a medieval social imaginary and entered a modern one. Not only are there glimpses of early modernist just war thought and a revolutionary reframing of natural law thinking in these texts, but they find their starting point in one of the most acute questions in all of just war thinking: how to understand and engage an “other,” most notably indigenous persons in the Americas and West Indies. Vitoria’s surprisingly progressive answers to this question moved the tradition forward, powering its increasing political scope and moral significance. They also shaped failures – most notably in funding modern notions of race and the rise of chattel slavery while also shaping early modern conceptions of property and ownership – and caused suffering for which the tradition is at least partly accountable and lacunae that it must now overcome as it moves into the environmental age.

H. Patrick Glenn has built his idea of legal traditions, common laws, and the cosmopolitan state by observing the evolution of law. He learned a lot from legal history. But what can legal historians learn from him? In this chapter, I show that his idea of legal traditions as normative information, which has spread into all legal systems in a large recursive process of appropriation and change, can be at least very stimulating for current attempts at a global legal history. The example of the School of Salamanca, which Glenn once described as Hispanic common law and which I will introduce in the first section of this chapter, shows the opportunities, but also the limits of his approach. The latter lie, in particular, in the fact that one can hardly analyse the processes of cultural translation observed without also taking into account praxeological aspects. It is precisely these conditions of the cultural translation of normative information that may have been of particular importance for the development of what Glenn envisioned as a ‘cosmopolitan law’.

A number of philosophical doctrines developed as responses to some mainstream views of the Iberian colonial period (roughly, from the late 1500s to the early 1800s). Chapter 1 of this book looks closely at four such doctrines whose central themes concerning Latin America can be traced to that period. It first examines the ideas of three Spanish thinkers, Bartolomé de las Casas (1474-1566), Francisco de Vitoria (1486-1546), and José de Acosta (ca. 1539-1600). The chapter demonstrates that Las Casas and Vitoria were set to determine the moral status of the Spanish conquest, and developed novel doctrines of practical ethics and political philosophy. Acosta raised empiricist objections to Scholasticism in epistemology and philosophy of science. Pressured by the new physical and social realities of the Americas, these three thinkers were among the early challengers of Thomism as interpreted in the Spanish world during the sixteenth century. But the chapter also examines what Edmundo O’Gorman (Mexican, 1906-1995) argued more recently against the myth of Columbus’ “discovery” of America. Clearly, the end of the colonial period was far from marking the end of reflection on philosophically interesting aspects of the Iberian expansion.

Chapter 2 undertakes to provide a critical narrative of the development and direction of international law as it was characterised by Catholic preoccupations from the Medieval and Early Modern era. Chapter 2 surveys the theological and philosophical contribution to the structure of premodern international law by Augustine, Thomas Aquinas, Francisco de Vitoria and Robert Bellarmine. They assisted the Catholic Church at crucial moments in its history and left an enduring legacy, which could broadly be described as a foundation for a Catholic cosmopolitan approach to international law. This process is highlighted and contrasted with the way early-modern international law was constructed. The structure of international law that emerged during the eventful sixteenth and seventeenth centuries led to Catholic political and legal thought becoming a minor key in the development of a secularised public international law in the nineteenth century. This distinctively different approach to sovereignty and international order provides an opportunity to examine the peripheral place of religion, particularly Catholicism, in the structure of nineteenth-century international law.

The author presents a necessarily brief summary of Catholic Social Teaching (CST) regarding immigration, featuring especially Pius XII's much neglected apostolic constitution Exsul familia. He also sets out some of the philosophical presuppositions of CST as it pertains to immigration. These presuppositions are to be found, he maintains, especially in the writings of Aristotle and Thomas Aquinas. He then examines in some detail Francisco de Vitoria's ideas regarding immigration, based as they are upon Aristotelian and Thomistic principles. Finally, he offers answers to questions that have arisen over the course of the essay.

The common good (bonum commune) has, since antiquity, referred to the aim of social and political association, and was particularly prominent in medieval Christian political theology. Since St. John XXIII’s 1961 encyclical letter, Mater et magistra, ecclesiastical statements about social teaching have employed a formulation of the common good, usually in the version that appeared in the Second Vatican Council’s 1965 Pastoral Constitution for the Church in the Modern World, Gaudium et spes, as “the sum of those conditions of social life that allow social groups and their individual members relatively thorough and ready access to their own fulfillment.” This chapter discusses the origins and development of this formulation as well as the ways that it has been used in subsequent Catholic Social Teaching. While it has sometimes been interpreted as an “instrumental” account of the common good, the sources and uses of the notion suggest that it is the particularly modern political component of a fuller notion of the common good continuous with the tradition. In particular, the recent formulation is concerned to limit the power of the modern state and protect the dignity of the human person in the challenging conditions of political modernity.