sion, and the opposing force of attraction, [considered] generally. We can indeed judge of this, their connection and consequences well enough à priori, whatever their relations among each other may be conceived to he, provided they do not contradict themselves; but [must] not lay claim to assume either of them as real, because to the admissibility of constructing an hypothesis, it is indispensably requisite that the possibility of what is assumed be quite certain, while with fundamental forces, their possibility can never be comprehended. And in this, the mathematico-mechanical mode of explanation has an advantage over the metaphysico-dynamical, which cannot be taken from it—namely, that from a completely homogeneous material, through the manifold form of the parts, by means of empty mediate spaces interspersed, it can accomplish a great specific multiplicity of matters, in density no less than in mode of action (if foreign forces be superadded). For the possibility of the forces, as well as of the empty mediate spaces, admit of demonstration with mathematical evidence; on the other hand, if the matter itself be transformed into fundamental forces (to define the laws of which, à priori, we are not in a position, and still less to indicate confidently a multiplicity of the same, sufficient for the explanation of the specific variety of matter), all means are wanting for the construction of this conception of matter, and for presenting as possible, in intuition, what we conceived in general. But a mere mathematical physics, pays for the foregoing advantage doubly on the other side, in that it first of all lays at its foundation an empty conception (that is, absolute impenetrability), and secondly that it must give up all the proper forces of matter, in addition to its original configuration of the fundamental matter and interspersion of empty spaces, and, after having called forth the need for explanation, must concede more freedom to the imaginative faculty in the field of philosophy—[and concede it] indeed as legitimate claim—than is consistent with the caution of the latter.
Instead of an adequate explanation of the possibility of matter and its specific variety, from the fundamental forces, which I am unable to furnish, I shall, as I hope, present the momenta to which its specific variety must
