And again:—"With his usual courage and sincerity he pushes his view to its utmost consequences. 'This view of the constitution of matter,' he continues, 'would seem to involve necessarily the conclusion that matter fills all space, or at least all space to which gravitation extends; for gravitation is a property of matter dependent on a certain force, and it is this force which constitutes the matter. In that view matter is not merely mutually penetrable; but each atom extends, so to say, throughout the whole of the solar system, yet always retaining its own centre of force.'" Faraday "compares the interpenetration of two atoms to the coalescence of two distinct waves, which though for a moment blended to a single mass, preserve their individuality, and afterwards separate." (Ibid. pp. 123-4 and note.)
The subject did not easily lose its hold on the philosopher's mind. "At the Institution," writes Dr. Bence Jones, "he gave eight lectures after Easter on the phenomena and philosophy of heat. He ended this course thus:—'We know nothing about matter but its forces—nothing in the creation but the effect of these forces; further our sensations and perceptions are not fitted to carry us; all the rest, which we may conceive we know, is only imagination.' He gave two Friday discourses: the first on the nature of matter, the other on recent improvements in the silvering of mirrors.
"His notes of the first lecture begin thus:—'Speculations dangerous temptations; generally avoid them; but a time to speculate as well as to refrain, all depends upon the temper of the mind. I was led to consider the nature of space in relation to electric conduction, and so of matter, i.e. whether continuous or consisting of particles with intervening space, according to its supposed constitution. Consider this point, remarking the assumptions everywhere.
"'Chemical considerations abundant, but almost all assumption. Easy to speak of atomic proportions, multiple proportions, isomeric and isomorphic phenomena and compound bases; and to account for effects we have only to hang on to assumed atoms the properties or arrangement of properties assumed to be sufficient for the purpose. But the fundamental and main facts are expressed by the term definite proportion,—the rest, including the atomic notion, is assumption.
"'The view that physical chemistry necessarily takes of atoms is now very large and complicated; first many elementary atoms—next compound and complicated atoms. System within system, like the starry heavens, may be right—but may be all wrong. Thus see how little of general theory of matter is known as fact, and how much is assumption.
"'Final brooding impression, that particles are only centres of force; that the force or forces constitute the matter; that therefore there is no space between the particles distinct from the particles of matter; that they touch each other just as much in gases as in liquids or solids; and that they are materially penetrable, probably even to their very centres. That, for instance, water is not two particles of oxygen side by side, but two spheres of power mutually penetrated, and the centres even coinciding.'" Bence Jones—Life of Faraday, Vol. II., pp. 177-78.
These views (best known as Boscovich's theory), though not generally held in scientific circles, are favoured by Bacon's most able commentator, Robert Leslie Ellis, and are pronounced by Professor Huxley a "tenable hypothesis." Mr. Spencer poises the balance as follows:—"Though the combining weights of the respective elements are termed by chemists their 'equivalents,' for the purpose of avoiding a questionable assumption, we are unable to think of the combination of such definite weights, without supposing it to take place between definite numbers of definite particles. And thus it would appear that the Newtonian view is at any rate preferable to that of Boscovich. A disciple of Boscovich, however, may reply that his master's theory is involved in that of Newton; and cannot indeed be escaped. 'What,' he may ask, 'is it that holds together the parts of these ultimate atoms?' 'A cohesive force,' his opponent must answer. 'And what,' he may continue, 'is it that holds together the parts of any fragments, into which, by sufficient force, an ultimate atom might be broken?' Again the answer must be—a cohesive force. 'And what,' he may still ask, 'if the ultimate atom were, as we can imagine it to be, reduced to parts as small in proportion to it, as it is in proportion to a tangible mass of matter—what must give each part the ability to sustain itself, and to occupy space?' Still there is no answer but—a cohesive force. Carry the process in thought as far as we may, until the extension of the parts is less than can be imagined, we still cannot escape the admission of forces by which the extension is upheld; and we can find no limit until we arrive at the conception of centres of force without any extension." First Principles, p. 54.
It is evident that Faraday was able to think in a manner which has been often declared impossible. Mr. Spencer's statement of the counter case is alone sufficient to prove that the inquiry is sure to be recurrent. We may add with Dr. Tyndall that facts alone cannot satisfy the mind, and that when a law is established, the question "why" is inevitable. Compare foot-note p. 324 post.
[193] A familiar instance of one among these abstract entities may convey to some readers a clearer idea of their nature than many careful explanations. Three balks of timber are lying in our road,—one, a very large and heavy monster, directly across it. Desirous of driving by, and being without adequate help to remove an obstacle beyond our strength, we call to mind the following definition. "The lever is an inflexible bar, capable of free motion about a fixed axis, called the fulcrum." (Newth. Natural Philosophy, p. 33.) Acting upon this idea, we place one balk we can manage to move, upon a second which happens to lie conveniently, and so roll away the third heavy monster. This done, we replace No. 1 peaceably beside No. 2, and wend on our way rejoicing. Now the lever, as defined by Newth, existed ideally in our mind, and we realised and used it. Our lever and fulcrum are still lying on the road, though they are lever and fulcrum no longer. The leverage was an applied mental Form, but we no longer want the Form to be operative,—and along with it the Force has disappeared.
[au] Our knowledge of Matter and of Motion;—our knowledge of their continuance while our forms and other forms are undergoing change;—all we most certainly know of the material world, resolves itself into our knowledge of Force. Thus far Mr. Herbert Spencer is with us, as may be seen from the following paragraphs from his First Principles. "By the indestructibility of Matter, we really mean the indestructibility of the force with which Matter affects us. As we become conscious of Matter only through that resistance which it opposes to our muscular energy, so do we become conscious of the permanence of Matter only through the permanence of this resistance; as either immediately or mediately proved to us. And this truth is made manifest not only by analysis of the à posteriori cognition, but equally so by analysis of the à priori one. For that which we cannot conceive to be diminished by the continued compression of Matter, is not its occupancy of space, but its ability to resist." (p. 179.) "It remains to be pointed out that the continuity of Motion, as well as the indestructibility of Matter, is really known to us in terms of force. That a certain manifestation of force remains for ever undiminished, is the ultimate content of the thought; whether reached à posteriori or à priori." (p. 182.) And again (pp. 191-2). "What, in these two foregoing chapters, was proved true of Matter and Motion, is, à fortiori, true of the Force out of which our conceptions of Matter and Motion are built. Indeed, as we saw, that which is indestructible in matter and motion, is the force they present. And, as we here see, the truth that Force is indestructible, is the obverse of the truth that the Unknown Cause of the changes going on in consciousness is indestructible. So that the persistence of consciousness, constitutes at once our immediate experience of the persistence of Force, and imposes on us the necessity we are under of asserting its persistence.... Consciousness without this or that particular form is possible; but consciousness without contents is impossible."