A central topic in the history of science is the transformation of the intellectual endeavour called ‘natural history’ during the eighteenth century that led to the emergence of modern scientific disciplines such as biology. An important aspect of this transformation involved, as Wolf Lepenies has stressed, the introduction of time in natural history. The ‘history’ in natural history used to refer mostly to the (to a greater or lesser extent theory-guided) presentation of the structure and empirical diversity in structure exhibited by nature. Over the course of the eighteenth century, the idea began to take hold in European scientific circles that such natural structure and its empirical diversity could be seen as the result of a historical process of development rather than of a brute fiat of creation. That idea, being novel, naturally encountered resistance, not just of a cultural and religious kind, but also of a more epistemological kind. The ‘historicising’ theories of nature offered during the period were often highly conjectural and sought the causes of nature’s current structures in prior events buried deep in astronomical and geological time and in causal principles of an unobservable kind. Understandably, many natural philosophers and natural historians worried that such conjectures did not and could not meet their scientific community’s standards of scientific rigour.

In this book, Andrew Cooper argues that central aspects of Kant’s critical philosophy, as well as of its development, should be understood against the background of debates over the status of such new approaches to natural history. That Kant responded to these developments and to some extent even played a role in them is not a novel thesis. But as Cooper stresses, many readers of Kant have found his position towards these developments to be cautiously negative to outright dismissive, stressing his misgivings about biology’s claims to scientific status as well as some of his contemporaries’ or even students’ early transformationist theories. Against this tendency in the literature, Cooper argues that ‘[i]n the midst of the epistemic and metaphysical problems raised by this transformation [of natural history], Kant aspired to determine the scientific character of historical claims’ (p. 6). Cooper’s aims in this book are therefore first and foremost a systematic study of Kant’s stance on natural history and its implications for our picture of his epistemology and philosophy of science. Since it is primarily in the context of natural historical debates that Kant offered his theory of human race, Cooper proposes to intervene in debates on Kant’s racism and on his role in the development of the concept of race. Finally, Cooper finds fault with the existing literature because it ‘does not sufficiently contextualize Kant’s account of scientific knowledge within the contested landscape of Newtonian science’ (p. 6). Hence, his work is also intended to contribute to the scholarship on the role of Newtonianism in eighteenth-century philosophy and science.

The first part of the book is devoted largely to sketching this context against which Cooper suggests Kant’s theories should be read, whereas the second and third parts deal with Kant’s engagements with natural history in his precritical and critical works, respectively. The two chapters of the first part pre-eminently discuss, in largely historical sequence, the development of two issues. One is the debate over the status of the classifications of natural entities traditionally undertaken in natural history. Such classifications, Cooper stresses, could either be taken to be natural, in the sense that they reflect real distinctions between natural kinds (i.e., that ‘cut nature at its joints’), or merely artificial classifications in terms of distinctions that are relevant or salient to us humans. Cooper also indicates that, in the course of the early modern period, the idea rose that a natural division must rely on causal understanding of natural things, that is, knowledge of how they are produced. Cooper argues that for both Linnaeus and Buffon, the distinctions between essential and accidental features, and the corresponding distinction between species and mere varieties, are made on the basis of knowledge of how such features are produced and reproduced.

The second issue Cooper addresses in the first part is the development of epistemological concerns over the status of hypotheses in early modern philosophy of science. He briefly addresses the role of conjecture in Descartes’ cosmogenetic fable and the more cautious ‘experimental’ version of the mechanical philosophy in British Royal Society circles. He then discusses Newton’s famous injunction on hypothesising in natural philosophy as well as the various ways in which authors inspired by him sought to overcome the limitations this injunction implied, which he subdivides into materialist, mechanist, and analogical Newtonianism. In the course of his discussion of this issue, Cooper also notes the important role many authors accorded to hypothesis and probability in the absence of strict science and the efforts they spent in formulating criteria for a hypothesis worthy of scientific consideration. He locates Du Châtelet’s influential vindication of the use of hypotheses in natural philosophy at the heart of this endeavour.

The second part of the book treats Kant’s precritical engagement with natural history. In the third chapter, Cooper argues that Kant’s Universal Natural History can be seen as a Newtonian work, against many who argue that it cannot be Newtonian because it contradicts Newton in many ways. Cooper sensibly argues that there was not just one way of being Newtonian in the eighteenth century, having distinguished at least three such ways in the second chapter, and that Kant can be seen as Newtonian in extending some novel aspects of Newton’s natural philosophy to aspects of nature where Newton himself would not want them applied, primarily to that of the history of the solar system. Cooper also argues that, in this early work, Kant is not reticent towards the historicising picture of natural history and believes that the conjectures it involves can have proper scientific status. In the fourth chapter, Cooper then traces the development of Kant’s thought on natural history until the 1770s, discussing the status of the claims of the physical geography lectures, Kant’s comments on generation in The Only Possible Proof and the Dreams of a Spirit-Seer, and his infamous paper on human races from the 1770s. Cooper argues that Kant regarded the historical conjectures of the physical geography as pragmatic in the sense that it does not provide explanations but aids us in finding explanations. In this chapter, Cooper also connects concerns over the status of natural historical conjectures with Kant’s epistemological concerns over the concept of causality in that period. Kant’s view that the connection between cause and effect cannot be comprehended but must be cognised from experience implies, Cooper submits, that the status of the claims of natural history must be hypothetical, since the effects and the causes it treats of are not always observable. Moreover, Cooper argues that Kant’s scientific metaphysics, according to ‘which the conditions of empirical inquiry are not determined by matter understood as extended substance but by the formal conditions of sensibility and the intellect … instructs us to build a physical system consisting of real connections between objects in time and space’ (p. 127).

In the final part of the book, Cooper argues that Kant’s critical philosophy can be understood as a continuation of the project of finding a legitimate use of hypotheses in natural history. In chapter 5, he argues that Kant’s regulative ideas in the appendix to the Transcendental Dialectic in the first Critique are best understood not as (illegitimate) hypotheses about the relationship between objects and their grounds, but rather as instructions to seek the grounds of objects. In this search, Cooper claims, hypotheses play an important role, and he therefore discusses Kant’s account of the minimal conditions a hypothesis must satisfy to be worthy of consideration (e.g., that the posited ground has ‘real possibility’, which means that it is at least an object of possible experience). In chapter 6, he then discusses the vicissitudes of Kant’s views on natural history throughout the second race paper and the controversies with Herder and Forster, in the course of which he stresses, against the scholarly consensus, Kant’s willingness to consider the kind of radical hypotheses that figure in a historicised natural history. Finally, in chapter 7, Cooper argues that the notoriously difficult-to-interpret antinomy of the teleological power of judgement does not involve a restriction of the injunction to explain things mechanistically but arises from the need of an additional maxim that is prompted by the natural historian’s attempt to classify natural entities according to descent.

As mentioned earlier, Cooper also develops an interpretation of Kant’s stance on human races and racial diversity. If I understand him correctly, he offers the plausible reading that this stance is not directly implied by Kant’s critical philosophy, which can at best determine what hypotheses can receive empirical support and what should count as such empirical support for a hypothesis. Rather, it involves a deplorable selectiveness on Kant’s part in the information on which he draws to assess the probability of hypotheses regarding the differences between human races.

Upon careful consideration, I have two worries about the argument developed in this book that pertain directly to its main theses. Cooper’s argument that the views of Kant he discusses should be understood against the background rests heavily on his presentation of that context. But that presentation is very selective. Cooper pauses only on a few main junctures in the debates on the development of theories of the history of the earth, theories of generation, and classification. In addition, in the first part of the book, he constantly moves from discussions concerning natural history to discussions of the role of hypotheses. I assume Cooper is convinced, and seeks to convince us, that these two issues are inextricably entwined. But that connection is not always apparent in the historical context or in the book. Descartes’ fable of the world is not a typical example of the kind of Cartesian (and early mechanist) hypothesis against which Newton is warning his readers, and Du Châtelet’s discussion of hypotheses is not directly related to issues in natural history. Moreover, the early modern debate on the status of probability and of hypotheses was far broader and concerned, in the eighteenth century, the application of probability theory to both scientific and philosophical theses. Hypotheses and probability were a standard topic in the German philosophy with which Kant engaged in much of his work. Cooper largely ignores the other contexts against which these passages can be read.

Cooper’s claim that Kant sought to establish natural history as a properly scientific endeavour can also be nuanced. His attack on those who, like Sloan, Zammito, and van den Berg, stress Kant’s misgivings about the prospects of the life sciences passes by the contrast Kant, like many early modern authors, drew between demonstrative science and mere probability. Certainly, like many others (including Locke, who appears here as a champion of probability), Kant admitted that, where demonstrative proof is not to be had, we need to avail ourselves of probabilities, which can be compared as to their degree of probability. Reassessing the place of hypothesis and probability in Kant’s philosophy of science would require reassessing its relation to demonstrative science. What we can learn from Cooper is perhaps that Kant’s reticence towards theories like Herder’s may not have rested on general aspects of his critical philosophy, but rather on the fact that, as a hypothesis, he finds these theses, even if metaphysically possible, empirically implausible. Finally, I am not always convinced by the readings of specific passages Cooper offers in which he connects higher-order aspects of Kant’s theory of knowledge with more lower-order concerns about scientific explanation. But these are disagreements over more technical details that cannot be addressed within the scope of a brief book review. In lieu, I recommend anyone interested in Kant’s philosophy of science or his engagement with the life sciences to read this new contribution to the debate and assess the evidence for themselves. Whether or not Cooper’s argument holds, it definitely merits consideration.