Michael Friedman

Kant's Metaphysical Foundations of Natural Science is one of the most difficult but also most important of Kant's works. Published in 1786 between the first and second editions of the Critique of Pure Reason, the Metaphysical Foundations occupies a central place in the development of Kant's philosophy, but has so far attracted relatively little attention compared with other works of Kant's critical period. Michael Friedman's book develops a new and complete reading of this work and reconstructs Kant's main argument clearly and in great detail, explaining its relationship to both Newton's Principia and eighteenth-century scientific thinkers such as Euler and Lambert. By situating Kant's text relative to his pre-critical writings on metaphysics and natural philosophy and, in particular, to the changes Kant made in the second edition of the Critique, Friedman articulates a radically new perspective on the meaning and development of the critical philosophy as a whole.

In this insightful study of the common origins of analytic and continental philosophy, Friedman looks at how social and political events intertwined and influenced philosophy during the early twentieth century, ultimately giving rise to the two very different schools of thought. He shows how these two approaches, now practiced largely in isolation from one another, were once opposing tendencies within a common discussion. Already polarized by their philosophical disagreements, these approaches were further split apart by the rise of Naziism and the resulting emigration of all influential German-speaking philosophers except for Heidegger. Although the book gives a general overview of the philosophical issues of the period, the author pays special attention to the relationships among three key twentieth-century philosophers: Rudolf Carnap, Ernst Cassirer, and Martin Heidegger.

his paper explores the relationship between Kant’s views on the metaphysical foundations of Newtonian mathematical physics and his more general transcendental philosophy articulated in the Critique of pure reason. I argue that the relationship between the two positions is very close indeed and, in particular, that taking this relationship seriously can shed new light on the structure of the transcendental deduction of the categories as expounded in the second edition of the Critique.Author Keywords: Kant; Mathematical physics; Transcendental deduction.

Immanuel Kant's Metaphysical Foundations of Natural Science (1786) provides metaphysical foundations for the application of mathematics to empirically given nature. The application that Kant primarily has in mind is that achieved in Isaac Newton's Principia (1687). Thus, Kant's first chapter, the Phoronomy, concerns the mathematization of speed or velocity, and his fourth chapter, the Phenomenology, concerns the empirical application of the Newtonian notions of true or absolute space, time, and motion. This paper concentrates on Kant's second and third chapters—the Dynamics and the Mechanics, respectively—and argues that they are best read as providing a transcendental explanation of the conditions for the possibility of applying the (mathematical) concept of quantity of matter to experience. Kant again has in mind the empirical measures of this quantity that Newton fashions in the Principia, and he aims to make clear, in particular, how Newton achieves a universal measure for all bodies whatsoever by projecting the static quantity of terrestrial weight into the heavens by means of the theory of universal gravitation. Kant is not attempting to prove a priori what Newton has established empirically but, rather, to clarify the character of Newton's mathematization by building Newton's empirical measures into the very concept of matter that is articulated in the Metaphysical Foundations.

I use recent work on Kant and diagrammatic reasoning to develop a reconsideration of central aspects of Kant’s philosophy of geometry and its relation to spatial intuition. In particular, I reconsider in this light the relations between geometrical concepts and their schemata, and the relationship between pure and empirical intuition. I argue that diagrammatic interpretations of Kant’s theory of geometrical intuition can, at best, capture only part of what Kant’s conception involves and that, for example, they cannot explain why Kant takes geometrical constructions in the style of Euclid to provide us with an a priori framework for physical space. I attempt, along the way, to shed new light on the relationship between Kant’s theory of space and the debate between Newton and Leibniz to which he was reacting, and also on the role of geometry and spatial intuition in the transcendental deduction of the categories.

In the Introduction to the Critique of Pure Reason Kant formulates what he calls “the general problem of pure reason,” namely, “How are synthetic a priori judgements possible?” Kant explains that this general problem involves two more specific questions about particular a priori sciences: “How is pure mathematics possible?” and “How is pure natural science possible?”— where the first concerns, above all, the possibility of Euclidean geometry, and the second concerns the possibility of fundamental laws of Newtonian mechanics such as conservation of mass, inertia, and the equality of action and reaction. In answering these questions Kant develops what he calls a “transcendental” philosophical theory of our human cognitive faculties — in terms of “forms of sensible intuition” and “pure concepts” or “categories” of rational thought. These cognitive structures are taken to describe a fixed and absolutely universal rationality — common to all human beings at all times and in all places — and thereby to explain the sense in which mathematical natural science represents a model or exemplar of such rationality.

What I call the dynamics of reason is a post-Kuhnian approach to the history and philosophy of science articulating a relativized and historicized version of the Kantian conception of the rationality and objectivity of the modern physical sciences. I here discuss two extensions of this approach. I argue that, although the relativized standards of rationality in question change over time, the particular way in which they do this still preserves the trans-historical rationality of the entire process. I also make a beginning in extending my historical narrative from purely intellectual history (both philosophical and scientific) to the wider cultural context.