It may be said here, parenthetically, that all these recent attempts (to one of which, by Prof. Challis, I had occasion to refer in my second paper) to construe the apparent attractions of bodies as cases of ethereal pressure and propulsion are simply returns to the state of scientific anarchy which prevailed in celestial mechanics before Newton's time. Prof. Spiller is evidently unaware that his theory—according to which, force is an "incorporeal matter"—is nothing but a reproduction of Kepler's speculations (not to speak of the Cartesian and Leibnitian theories to which I have already alluded), in which the vortices supposed to carry the planets along with them were asserted to be an "immaterial species," capable of overcoming the inertia of bodies. It is plain that this "immaterial species" is the same wooden iron which Spiller exhibits under the name of "incorporeal matter," the only difference being that the absurdity of Kepler's chimera was less glaring in the hazy dawn of the mechanical notions of his time, than the extravagance of Spiller's conceit in the light of the scientific atmosphere of our day.
It is almost superfluous to say to the intelligent reader of these papers that Spiller's "dead matter" is a nonentity, inasmuch as we know nothing of material reality except through its action. And it is hardly worth while to point out in detail that the hypothesis of dead atoms is not only inadmissible, but wholly useless. Unchangeable particles destitute of gravity and all other force, even if the action of force upon them were conceivable, must be equally acted upon from all sides by the omnipresent ether, and could, therefore, in no wise help to establish differences of density, or other differences not contained in or evolvable from the ether itself. They could not even add to the extension of a body, much less to its hardness, being wholly without the power of resistance; but, waiving this, and granting for a moment that extension without resistance is possible, they would simply be bubbles of void space encysted in the universal ether, and to the differentiation of this ether alone all the phenomena of the material world would be due.
The truth is, that absolutely passive, dead matter is as unknown in experience as it is inconceivable in thought. Every particle of matter of which we have any knowledge attracts every other particle in conformity to the law of gravitation; and every material element exerts chemical, electrical, magnetic, thermic, and similar forces upon other elements which in respect to these forces are its correlates. The whole presence of matter to the senses consists in the manifestation of power, in the exhibition of force. All this has been very clearly seen and very explicitly stated by numerous physicists; but, unfortunately, by most of them it has been speedily lost sight of in their ulterior speculations.
In what sense, then, can inertia be truly predicated of matter?
- Among those whose comprehension of this is clear, is M. Comte; his observations upon the subject ("Philosophic Positive," tome i., p. 375, et seq.) merits attentive perusal.