Kant’s Formulation of the Laws of Motion

Abstract

Kant’s interpretation of the mathematics of motion is to be found in his Metaphysical Foundations of Natural Science in the form of one fundamental principle of kinematics and three laws of mechanics. None of these propositions is especially original with Kant so far as the sheer mathematics goes, but the selection of just these four propositions and Kant’s proof for each of them are at the very least strongly influenced by the special features of his critical philosophy. Before turning to details I should like to consider what Kant takes to be the significance and usefulness of the subject of metaphysical foundations of natural science (which in its strictest, and for Kant, most proper sense, is the metaphysical doctrine of corporeal nature). Kant’s claims are, as usual, in one sense very modest and in another sense magnificently presumptuous: modest in that he thinks his achievement “no great work” [kein grosses Werk]; presumptuous in that he believes himself to have once and for all exhaustively investigated his subject. In any case, Kant does claim that all mathematical physicists, however much they may seek to ‘repudiate any claim of metaphysics on their science’, must, at least implicitly, make use of the principles which he is about to elucidate.

This work was supported in part by the National Science Foundation (Grant GS 2413). I am indebted for several helpful discussions to Dr. Jürgen Ehlers of the Max Planck Institute in Munich.