[Footnote 1:  In each particular science of nature, science proper (i.e., apodictically certain science) is found only to the extent in which mathematics can be applied therein.  For this reason chemistry can never be anything more than a systematic art or experimental doctrine; and psychology not even this, but only a natural history of the inner sense or natural description of the soul.  That which Kant’s Metaphysical Elements of Natural Science, 1786—­in four chapters, Phoronomy, Dynamics, Mechanics, and Phenomenology—­advances as pure physics or the metaphysics of corporeal nature, is a doctrine of motion.  The fundamental determination of matter (of a somewhat which is to be the object of the external senses) is motion, for it is only through motion that these senses can be affected, and the understanding itself reduces all other predicates of matter to this.  The second and most valuable part of the work defines matter as the movable, that which fills space by its moving force, and recognizes two original forces, repulsive, expansive superficial force or force of contact, by which a body resists the entrance of other bodies into its own space, and attractive, penetrative force or the force which works at a distance, in virtue of which all particles of matter attract one another.  In order to a determinate filling of space the co-operation of both fundamental forces is required.  In opposition to the mechanical theory of the atomists, which explains forces from matter and makes them inhere in it, Kant holds fast to the dynamical view which he had early adopted (cf. p. 324), according to which forces are the primary factor and matter is constituted by them.]

The outcome of the Analytic of Principles sounds bold enough. The understanding is the lawgiver of nature:  “It does not draw its laws a priori from nature, but prescribes them to it”; the principles of the pure understanding are the most universal laws of nature, the empirical laws of nature only particular determinations of these.  All order and regularity take their origin in the spirit, and are put into objects by this.  Universal and necessary knowledge remained inexplicable so long as it was assumed that the understanding must conform itself to objects; it is at once explained if, conversely, we make objects conform themselves to the understanding.  This is a reversal of philosophical opinion which may justly be compared to the Copernican revolution in astronomy; it is just as paradoxical as the latter, but just as incontestably true, and just as rich in results.  The sequel will show that this strangely sounding principle, that things conform themselves to our representations and the laws of nature are dependent on the understanding, is calculated to make us humble rather than proud.  Our understanding is lawgiver within the limits of its knowledge, no doubt, but it knows only within the limits of its legislative authority; nature, to which it dictates laws, is nothing but a totality of phenomena; beyond the limits of the phenomenal, where its commands become of no effect, its wishes also find no hearing.