This chapter sets out the origins of the traditional historiography of early modern philosophy based on the dichotomy of empiricism and rationalism. After reconstructing the spread of the notions of empiricism and rationalism in Germany during the 1780s, we argue that the first outline of a history of metaphysics that displays the Kantian, epistemological, and classificatory biases can be found in Karl Leonhard Reinhold’s works from the early 1790s. Two early Kantian historians, Wilhelm Gottlieb Tennemann and Johann Gottlieb Buhle, turned Reinhold’s outline into fully fledged histories of early modern thought. Tennemann, who became a Kantian after reading Reinhold’s works, developed Reinhold’s historical sketches into a detailed, nuanced, and comprehensive account of seventeenth- and eighteenth-century philosophy that revolves around the empiricism/rationalism distinction and displays the biases of the traditional historiography. Thus, in Germany, the decline of experimental philosophy and the eclipse of the experimental/speculative distinction went hand in hand with the rise of Kantianism and the development of a historiography based on the empiricism/rationalism distinction.

This chapter examines the impact of experimental philosophy in France from the mid-1730s through to the period in which the philosophes were at the forefront of French intellectual life, the period normally called the French Enlightenment. The chapter opens with a discussion of the reception of Bacon’s views about natural history and the acceptance of experimental philosophy more generally in the early Parisian Academy. It then turns to the heyday of experimental philosophy in France which began in the mid-1730s with its promotion by the likes of Voltaire and Comte de Buffon, and the courses in experimental philosophy taught by Abbé Nollet. It is argued that the anti-speculative sentiment so prevalent in Britain manifests itself in the anti-system debate in France. And the chapter goes on to examine the alignment between Buffon’s conception of natural history and that of Bacon, the Baconianism of Denis Diderot, and the influence of experimental philosophy on Jean Le Rond d’Alembert as manifest in his ‘Preliminary Discourse’ to the Encyclopédie. The chapter concludes with an appraisal of the rehabilitation of Descartes, who up to that point had come to be regarded by many as the archetypal speculative philosopher.

After summarising our findings in the preceding chapters, the Conclusion assesses the relative merits of experimental philosophy and empiricism as historiographical categories, and in the process we respond to some of our critics. We examine the historicity of both notions, their disciplinary and chronological scope, their contrast classes, namely, speculative philosophy and rationalism, and their explanatory power. Through an examination of the anti-hypotheticalism so prevalent in the early modern period and Margaret Cavendish’s published critique of experimental philosophy, we argue that experimental philosophy, together with the experimental/speculative distinction, have more explanatory power than the rationalism/empiricism distinction.

The Introduction provides the rationale for the writing of a history of early modern experimental philosophy and introduces the book’s major themes. It opens with a discussion of the meaning of the term ‘experimental philosophy’ and explains how it should be differentiated from contemporary x-phi and the historiographical category of empiricism. We claim that ‘experimental philosophy’ initially referred to a method for acquiring knowledge of nature that prioritises observation and experiment over theory, but it soon became the referent for the movement of experimental philosophers – as its practitioners called themselves – and for the actual knowledge acquired by this method. The Introduction then sets out some of the broader philosophical context in which experimental philosophy emerged, including the role of principles, the two-step approach to developing a science of nature, the experimental/speculative distinction, its employment of a form of natural history deriving from Francis Bacon, and a clutch of philosophical problems that impinged on this new approach to knowledge acquisition. These include the problems of how we get epistemic access to the essences of material things, how to articulate the precise relationship between experiment and observation on the one hand and theory on the other, and the roles of natural history and mathematics in experimental natural philosophy. The Introduction concludes with a summary of each chapter of the book.

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.