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Modern Science, Metaphysics, and Mathematics

C. The Mathematical Character of Modern Natural Science; Newton's First Law of Motion


Modern thought does not appear all at once. Its beginnings stir during the later Scholasticism of the fifteenth century; the sixteenth century brings sudden advances as well as setbacks; but it is only during the seventeenth century that the decisive clarifications and foundations are accomplished. This entire happening finds its first systematic and creative culmination in the English mathematician and physicist Newton, in his major work, Philosophiae Naturalis Principia Mathematica, 1686-87. In the title, "philosophy" indicates general science (compare "Philosophia experimentalis"); "principia" indicates first principles, the beginning ones, i.e., the very first principles. But these starting principles by no means deal with an introduction for beginners.

This work was not only a culmination of preceding efforts, but at the same time the foundation for the succeeding natural science. It has both promoted and limited the development of natural science. When we talk about classical physics today, we mean the form of knowledge, questioning, and evidence as Newton established it. When Kant speaks of "science," he means Newton's physics.

This work is preceded by a short section entitled "Definitiones." These are definitions of quantitas materiae, quantitas motus, force, and, above all, vis centripeta. Then there follows an additional scholium that contains the series of famous conceptions of absolute and relative time, absolute and relative space, and finally, of absolute and relative motion. Then follows a section with the title "Axiomata, sive leges motus" ("Principles or Laws of Motion"). This contains the proper content of the work. It is divided into three volumes. The first two deal with the motion of bodies, de motu corporum, the third with the system of the world, de mundi systemate.

Here we shall merely take a look at the first principle, i.e., that Law of Motion which Newton sets at the apex of his work. . . . "Every body continues in its state of rest, or uniform motion in a


Martin Heidegger (GA 41) Modern Science, Metaphysics, and Mathematics - Basic Writings (1993)