This chapter turns from France to Scotland and from natural philosophy to moral philosophy. Through an examination of a number of leading Scots moral philosophers, we examine the impact of experimental philosophy on the project of the science of man in the Scotland of the eighteenth century. While it is incorrect to speak a movement of experimental moral philosophy in eighteenth-century Scotland, the impact of this new approach to natural philosophy is evident in its critique of speculation and hypotheses, in the roles that moral philosophers accorded to experiment and observation, in the rudimentary philosophy of experiment found in the writings of David Hume, and in the attempts by Scottish moral philosophers, such as George Turnbull, to apply the method of natural history and to incorporate analogues of physical laws in their theories. This chapter provides us with ample evidence for the claim that experimental philosophy had a decisive impact on the development of Scottish moral philosophy of the eighteenth century.

This chapter traces the emergence of experimental philosophy in England from the late 1650s in the precursor groups to the Royal Society and, in particular, in the natural philosophical method of Robert Boyle. It provides a detailed examination of the development of Boyle’s experimental philosophy and an overview of the adoption of experimental philosophy by many virtuosi in the fledgling Royal Society. From there it turns to early opposition to experimental philosophy by the likes of Meric Causabon and Margaret Cavendish, and the application of the methodology in English medicine, particularly amongst the chymical physicians. The next sections of the chapter examine the spread of experimental philosophy to the Continent and its impact on religion. The new approach to natural philosophy was said to have a positive effect on those who practise it, and its principles were soon applied in both natural religion and Christian apologetics. Finally, we turn to the questions of the shifting speculative targets of the experimental philosophers, pointing out that Descartes’ vortex theory came in for particularly harsh criticism, and the conceptual question as to who qualifies as an experimental philosopher.

The chapter presents the two late religio-political works of Pufendorf in his role as lay theologian Pufendorf, Of the Nature and Qualification of Religion in Reference to Civil Society (1687), and The Divine Feudal Law; or, Covenants with Mankind (1695). Both tracts consider the changes in religion and politics since the revocation of the tolerance edict of Nantes in 1685 and the acceptance of Huguenots in Protestant Brandenburg-Prussia. Pufendorf’s defence of Protestant positions and severe criticism of French expansionism and Papal supremacy are explained with reference to the respective political and ecclesial theological contexts that had developed since around 1600 (1). Pufendorf’s first tract argues for political toleration of more than one Christian confession and public worship in the state. This is possible because political sovereignty, based on natural law, and religious autonomy, based on the purely religious ends of churches, can and should coexist (2). The biblical reasoning behind this is intensified in the second tract, which argues for mutual appreciation and reconciliation of the Lutheran and Reformed (Calvinist) confessions. Here Pufendorf integrates his concept of natural law into a new, strictly biblical covenantal theology correlating God’s promises and men’s free obedience (3).

Chapter 6 argues that it is Kierkegaard, rather than Kant, who denies that religion is anything beyond or above ethics. It thus criticizes the widespread view that Kierkegaard reacted against Kant’s (alleged) reduction of religion to ethics by introducing the “teleological suspension of the ethical.” First, Kierkegaard rules out secular ethics by identifying the good and the divine. Second, he moralizes religion by interpreting natural religion in terms of non-Christian ethics and Christianity in terms of Christian ethics. For Kierkegaard, the first two are necessary yet insufficient, so that Christian ethics may only partially replace non-Christian ethics. As a result, there is no suspension of ethics in general, only a suspension of one variant of it by another variant. Even in the case of Abraham’s sacrifice of Isaac, Kierkegaard’s position is far more defensible than normally assumed, since he maintains that it would have been “an error on [Abraham’s] part,” if he were to murder Isaac (SKS 24, 375, NB24:89 / KJN 8, 379). Finally, he denies that anyone could possibly imitate Abraham’s sacrifice by killing someone.

Grotius drew mainly upon the Catholic moral theologians, but his theory of contract law is set in the different perspective of his ‘secular’ natural law system.

Although The Spirit of Law (1748) was greeted very favorably in many quarters, a Jansenist writer in the Nouvelles Ecclésiastiques charged Montesquieu with lack of respect for Christianity and with being a follower of natural religion. Montesquieu’s response was that his critic had failed to understand that he was writing, not as a theologian, but as a “jurisconsult” (legal scholar) exploring what laws are most suitable for a given people considering their character and situation. Montesquieu acknowledges that although he had discussed many non-Christian customs, he was “not justifying the customs but giving the reasons for them.” He also stressed that he had rebutted the views of both Bayle and Spinoza. He notes that he had called out Bayle for his error in believing that “a society of true Christians could not survive” and had refuted Spinoza’s fatalism by asserting that “those who have said that a blind fate has produced all the effects that we see in the world have uttered a great absurdity.”

The idea of religious liberty is sometimes thought to be necessary precisely because people will not agree on religious opinions. Yet the American tradition of religious freedom is grounded in the reality of both revealed religion and natural religion. While revealed religion, which is more contentious, is most often the subject of First Amendment cases, religious liberty need not presuppose that all religious knowledge is impossible. Instead, the Declaration of Independence famously affirms natural religion: that some things about God, human nature, and individual rights are knowable by reason. This chapter considers areas of natural religion, reason, and presuppositional thinking in order to show how knowledge is possible and how greater agreement can be achieved concerning religion.

Religion was a central concern of the thinkers of the Scottish Enlightenment with David Humes sceptical engagement with religion earning him the reputation of being an infidel. Accordingly, this chapter falls into three parts. The first explores the state of the subject before Hume wrote, distinguishing between an orthodox tradition for which theology was the primary science that could dictate terms of reference to philosophy, and a new, largely imported (English and Dutch), tradition of rational religion that subjected the whole framework of religious belief to the same rational critique as other forms of knowledge and belief. With the context established, the second part of the chapter will concern Hume, represented especially by two essays in his Philosophical Essays (later called An Enquiry) concerning Human Understanding (1748), his Natural History of Religion (1757), and his Dialogues concerning Natural Religion (first published in 1779 but known to some in manuscript from the 1750s). His Treatise of Human Nature (1739-40) was the seminal work that first presented his sceptical philosophy and its supporting psychology, and it had implications for religious as for any other belief; these implications were suppressed prior to publication, but were not lost on contemporaries who expected an analysis of the human mind to culminate as a matter of course in an account of the foundations of religious belief. The final part of the chapter will summarise the Scottish and English response to Hume in the debate over a rational theology. In his appraisal of arguments for the existence and attributes of God, and arguments about the credibility of ancient revelation, Hume s philosophy almost inevitably brought him into conflict with ministers of the Kirk.