Section 15
Original German
§ 15.
Nun sind wir gleichwohl wirklich im Besitze einer reinen Naturwissenschaft, die a priori und mit aller derjenigen Nothwendigkeit, welche zu apodiktischen Sätzen erforderlich ist, Gesetze vorträgt, unter denen die Natur steht. Ich darf hier nur diejenige Propädeutik der Naturlehre, die unter dem Titel der allgemeinen Naturwissenschaft vor aller Physik (die auf empirische Principien gegründet ist) vorhergeht, zum Zeugen rufen. Darin findet man Mathematik, angewandt auf Erscheinungen, auch blos discursive Grundsätze (aus Begriffen), welche den philosophischen Theil der reinen Naturerkenntniß ausmachen. Allein es ist doch auch manches in ihr, was nicht ganz rein und von Erfahrungsquellen unabhängig ist: als der Begriff der Bewegung, der Undurchdringlichkeit (worauf der empirische Begriff der Materie beruht), der Trägheit u. a. m., welche es verhindern, daß sie nicht ganz reine Naturwissenschaft heißen kann; zudem geht sie nur auf die Gegenstände äußerer Sinne, also giebt sie kein Beispiel von einer allgemeinen Naturwissenschaft in strenger Bedeutung, denn die muß die Natur überhaupt, sie mag den Gegenstand äußerer Sinne oder den des innern Sinnes (den Gegenstand der Physik sowohl als Psychologie) betreffen, unter allgemeine Gesetze bringen. Es finden sich aber unter den Grundsätzen jener allgemeinen Physik etliche, die wirklich die Allgemeinheit haben, die wir verlangen, als der Satz: daß die Substanz bleibt und beharrt, daß alles, was geschieht, jederzeit durch eine Ursache nach beständigen Gesetzen vorher bestimmt sei, u. s. w. Diese sind wirklich allgemeine Naturgesetze, die völlig a priori bestehen. Es giebt also in der That eine reine Naturwissenschaft, und nun ist die Frage: wie ist sie möglich?
Musean translation
Mouseia’s complete machine-assisted Musean translation, made directly from the complete German of the Prolegomena (AA IV 253–383, all §§1–60 and the Appendix), for fidelity, the steps of Kant’s argument, clarity and structure.
§ 15.
Yet we do in fact possess a pure natural science, which sets forth a priori, and with all the necessity required of apodictic propositions, laws to which nature is subject. I need only call as witness here that preliminary study of nature which, under the title of general natural science, precedes all physics (which is grounded on empirical principles). In it we find mathematics applied to appearances, as well as merely discursive principles (drawn from concepts), which constitute the philosophical part of pure cognition of nature. Yet it also contains much that is not entirely pure and independent of experiential sources: the concepts of motion, of impenetrability (on which the empirical concept of matter rests), of inertia, and others, which prevent it from being called a wholly pure natural science. Moreover, it concerns only the objects of the outer senses, and so provides no example of a universal natural science in the strict sense. For such a science must bring nature in general under universal laws, whether it concerns the object of the outer senses or that of inner sense—the object of physics as well as of psychology. But among the principles of that general physics there are some that really do possess the universality we require: for instance, the proposition that substance remains and persists; that everything that happens is always determined beforehand by a cause according to constant laws; and so on. These are truly universal laws of nature, which hold entirely a priori. Thus there actually is a pure natural science, and the question now is: how is it possible?
Plain English translation
Mouseia’s complete Plain English edition, made independently and directly from the same complete German text.
§ 15.
Yet we really do possess a pure natural science. It sets out a priori the laws governing nature, with all the necessity required for propositions that are absolutely certain. I need only point to the preparation for the study of nature known as general natural science. It comes before all physics, which is based on empirical principles. It contains mathematics applied to appearances. It also contains purely discursive principles, drawn from concepts, which make up the philosophical part of pure cognition of nature. Still, it also contains much that is not entirely pure and independent of experience. Examples are the concepts of motion, impenetrability—on which the empirical concept of matter rests—and inertia, among others. These prevent it from being called entirely pure natural science. Moreover, it deals only with objects of the outer senses. So it gives no example of a general natural science in the strict sense. Such a science must bring nature in general under universal laws, whether it concerns objects of the outer senses or of inner sense: the objects of physics as well as of psychology. But some principles of that general physics really do have the universality we require. Examples are the propositions that substance remains and persists, and that everything that happens is always determined in advance by a cause according to constant laws, and so on. These really are universal laws of nature that hold entirely a priori. So there actually is a pure natural science. The question now is: how is it possible?
About this section
Section 15 is part of Prolegomena to Any Future Metaphysics by Immanuel Kant. This page sets the German original beside 2 direct-source translations, so any line can be checked against the source. It is section 21 of 72 in the work, which is kept in the European tradition.
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