The combination of the title and subtitle of Kant's Organicism:Epigenesis and Development of Critical Philosophy (University of Chicago Press, 2013) may be surprising at first. The term organicism, in its broad meaning, might refer to a philosophical account which views the universe and its parts as organic wholes and-either by analogy or literally-as living organisms. Featuring in the title of a book on Kant, however, seems to suggest that the term is being used in a distinctive sense. Notions such as epigenesis, development, and philosophy, on the other hand, have much more specific meanings, which seem to refer both to the history of the of science (epigenesis) and to the history of per se, with the term philosophy used to refer to Kant's groundbreaking revolution in and, one might expect, to those perspectives that arose from, or built on, the Kantian legacy. Mensch's book guides us in a journey whereby the terms and contexts introduced in the title and subtitle are effectively brought together. Kant's Organicism is an ambitious book-but also a book that ultimately delivers on its ambition.The book commences with the author distinguishing the preformative and theories of reproduction that flourished in the eighteenth century, and remarking that the debate between these two models was particularly active during the two decades before Kant's publication of the Critique of Pure Reason. After having traced the history of the life sciences as Kant would have come to know them, the book moves to an examination of the nature of the influence of those sciences on the critical system. The main thesis of the book is that epigenesist models had a significant role to play for Kant's theory of cognition, and an especially significant role for that which Mensch even goes so far as to describe as Kant's epigenesist of mind. By using the model in the theoretical context (a model which, interestingly, Kant rejected as a convincing explanation in the natural realm), Kant came to believe, Mensch argues, that like an organism, cognition functioned as a set of parts whose thoroughgoing connection realized unity even as the grounds of that unity preceded it (12).The book is very carefully structured. The first part, while ambitiously engages in an original reinterpretation of several issues in the field of the history of the of science, also manages to be very informative to those who have a very limited prior knowledge of such issues. The second part is more directly devoted to supporting the main thesis of the book, which I briefly outlined above-and this is the part of the book that I personally find more stimulating. There are, of course, several angles from which Mensch's book and its arguments can be addressed and commented upon. Because of space constraints, and to avoid any impressionistic reading of such work (something that definitely does not deserve), I will focus my attention on two main points. The first is Leibniz's contribution to the notion of organism, and the way in which Kant departed from Leibniz's account. I see my discussion of Leibniz as complementing what Mensch argues in the book rather than as objecting against any key argument she advances, because I find such arguments very convincing. The second point is a brief discussion of some issues in the light of a possible development of Mensch's main line of argument beyond Kant and into the further development of post-Kantian philosophy.Very early in his scholarly work, Leibniz subscribed to the method pioneered by Galileo Galilei, and often emphasized that the philosophers were not so distant, after all, from (Aristotelian) philosophy: categories such as figure size movement were, after all, only the transformation of the Aristotelian categories of form matter and mutation.1 This is not to say that the modern categories and the ancient categories are perfectly exchangeable: Leibniz's endorsement of the modern, scientific approach is evidence of his firm belief that such an approach represents a clear advancement with respect to the conceptual instruments of philosophy. …