This paper examines the origin, range and meaning of the Principle of Action and Reaction in Kant’s mechanics. On the received view, it is a version of Newton’s Third Law. I argue that Kant meant his principle as foundation for a Leibnizian mechanics. To find a ‘Newtonian’ law of action and reaction, we must look to Kant’s ‘dynamics,’ or theory of matter. I begin, in part I, by noting marked differences between Newton’s and Kant’s laws of action and reaction. I (...) argue that these are explainable by Kant’s allegiance to a Leibnizian mechanics. I show (in part II) that Leibniz too had a model of action and reaction, at odds with Newton’s. Then I reconstruct how Jakob Hermann and Christian Wolff received Leibniz’s model. I present (in Part III) Kant’s early law of action and reaction for mechanics. I show that he devised it so as to solve extant problems in the Hermann-Wolff account. I reconstruct Kant’s views on ‘mechanical’ action and reaction in the 1780s, and highlight strong continuities with his earlier, pre-Critical stance. I use these continuities, and Kant’s earlier engagement with post-Leibnizians, to explain the un-Newtonian features of his law of action and reaction. (shrink)

Michael Friedman's Kant and the Exact Sciences (1992) refocused scholarly attention on Kant's status as a philosopher of the sciences, especially (but not exclusively) of the broadly Newtonian science of the eighteenth century. The last few years have seen a plethora of articles and monographs concerned with characterizing that status. This recent scholarship illuminates Kant's views on a diverse group of topics: science and its relation to metaphysics; dynamics and the theory of matter; causation and Hume's critique of it; and, (...) the limits of mechanism and of mechanical intelligibility. I argue that recent interpretations of Kant's views on these topics should influence our understanding of his principal metaphysical and epistemological arguments and positions. (shrink)

Kant’s natural philosophy in the Metaphysical Foundations of Natural Science is heavily influenced by Newton’s Principia. However, a closer look makes it clear that Kant’s project has also been influenced by other thinkers. One of these thinkers is Leonard Euler. His work was of great influence for Kant, not only with regards to his view on space and inertia but on the relation between metaphysics and natural science in general. Even though Euler’s Physics built on Newton’s work, he differs from (...) him in fundamental regards, leading to crucial developments inside classical mechanics. Here I will discuss the influence of Euler on the work of Kant and focus on Euler’s view on the two entangled problems of inertia and space. It will become clear that both Euler and Kant went through a development concerning these fundamental notions. After shortly highlighting the differences between Kant and Newton, I shall go through the development of important parts of Euler’s natural philosophy concerning the above mentioned themes. I intend to demonstrate that he, through his refutation of Wolffianism, became an advocate for the necessity of absolute space but also denied the existence of an internal force of inertia. After that I will show how Kant’s reading of Euler lead to crucial changes of his natural philosophy in particular and his philosophical enterprise in general. I therefore analyze Kant’s revision of his theory of space and inertia in his precritical writings. Building upon that, I will show the influence of these thoughts on his Metaphysical Foundations. (shrink)

I argue that recent advances in developmental biology demonstrate the inadequacy of suborganismal mechanism. The category of the organism, construed as a ’natural purpose’ should play an ineliminable role in explaining ontogenetic development and adaptive evolution. According to Kant the natural purposiveness of organisms cannot be demonstrated to be an objective principle in nature, nor can purposiveness figure in genuine explain. I attempt to argue, by appeal to recent work on self-organization, that the purposiveness of organisms is a natural phenomenon (...) and, by appeal to the apparatus of invariance explanation, that biological purposiveness provides genuine, ineliminable biological explanations. (edited). (shrink)

In this essay, I call attention to Kant’s and Whewell’s attempt to provide bridging principles between a priori principles and scientific laws. Part of Kant’s aim in the Opus postumum (ca. 1796-1803) was precisely to bridge the gap between the metaphysical foundations of natural science (on the Metaphysical Foundations of Natural Science (1786) see section 1) and physics by establishing intermediary concepts or ‘Mittelbegriffe’ (henceforth this problem is referred to as ‘the bridging-problem’). I argue that the late-Kant attempted to show (...) that the concept of ‘moving force’, an intermediary concept derived from a priori principles, could be given empirical content so that concrete scientific knowledge is arrived at. Thus, the late-Kant wished not only to show that proper scientific laws are necessary a priori (as he had shown in the Metaphysical Foundations of Natural Science) but also that intermediary concepts could be derived from a priori principles which, when interpreted empirically, resulted in the specific forces as established by physics (see section 2). Of course, William Whewell never knew about Kant’s Opus postumum and his attempt to bridge the gap between the metaphysical foundations of science and physics. However, it is striking that Whewell had similar concerns about the Critique of Pure Reason and the Metaphysical Foundations of Natural Science as Kant himself. According to Whewell, the Kantian project was incomplete because it did not show how ‘modifications’ (in the sense of concretizations) of a priori principles could result in empirical laws (section 3). Next, it will be argued, by taking into account several of Whewell’s philosophical notebooks which have scarcely been studied systematically, that Whewell’s doctrine of Fundamental Ideas grew out of his dissatisfaction with the Kantian project with respect to the bridging problem and that his own philosophical position should be seen as an attempt to bypass the bridging-problem. (shrink)

Kant’s “principle of equality governing the actions and counter-actions” belongs not only to the Metaphysical Foundations of Natural Sciences, but also to his practical philosophy. Kant’s Idea for a Universal History with a Cosmopolitan Purpose and On the Common Saying: That may be Correct in Theory, but it is of no Use in Practice may contribute to the understanding of the “principle of equality governing the actions and counter-actions” in the latter writing, and vice-versa. Referring to all three, this paper (...) tries to show that, in the context of his concept of right, Kant understands the principle of the equality of action and reaction in two different senses, which he combines: a dynamic one and a legal one. (shrink)

On an influential view, Newton's mechanics is built into Kant's very theory of exact knowledge. However, Newtonian dynamics had serious explanatory limits already known by 1750. Thus, we might worry that Kant's Analytic is too narrow to ground enough exact knowledge. In this paper, I draw on Enlightenment dynamics to show that Kant's notion of determinate objecthood is sufficiently broad, non-trivial, and still relevant to the present.