CHAPTER IV.

THE NATURE OF MATTER.

69. THE solution sketched in the foregoing pages affords no answer to the (irrational) question, What is the nature of Matter in itself, and apart from its properties? Those readers who have grasped the leading purpose of this work will have recognized the irrationality of the question, and will have seen that to know the properties of Matter is to know what Matter is. The logical distinction of the abstraction from its concretes is a convenient artifice; but the subsequent erection of the abstraction into an independent existence is a speculative. illusion fraught with danger. It is aided by the natural desire to extend knowledge, and by the metempirical desire to get behind the phenomena, - a desire which leads to an interminable regress, since there will always. be an equal justification in attempting a why of the why, a cause of the cause, unless the mind acquiesces in fixed ultimates. What are the ultimates? Since knowledge is classification of observed phenomena, a systematization of the Known, not a divination of the Unknown, the ultimates of Feeling are the fixed limits of research; and carrying the Logic of Feeling into the higher region of the Logic of Signs (which are only signs of feelings), we there find the ultimates of Speculation to be those equations which express what may be called the forms of the functions (see Vol. I. p. 164), — all Observation being simply of the functions of the unknown quantities.

Stated in a less abstract way, it may be said that all we can positively know of anything, cosmical or mental, is how we are affected by it; and the various Provinces of Feeling (§ 39) are so many ultimate divisions, while the various Conceptions which symbolize these groups of Experience are also ultimates of their kind; so also are the general relations which they present. We cannot reduce a sensation of Color to a sensation of Heat or Sound, nor the conception of Matter to the conception of Force, the conception of Quality to that of Quantity, or that of Time to that of Space. These are ultimates; we cannot get beyond them to see their derivation. If the idle metempirical question arises, What lies beyond the conditions of a sensation of color or a conception of quantity? we can only answer, The whole universe lies beyond it; and you may then ask, What beyond the universe? and so on in interminable questions, the inanity of which is manifest in this, that could the questions be answered, they would in no sense affect our dealings with the facts before us; we should know absolutely nothing more of color or of quantity by knowing what preceded them, or existed beyond their conditions of existence. If we unite all sensations under some general group of Feeling, according to the unifying tendency of Speculation, and all qualities under some general group of the Felt, and all law under one law, this must not lead us to overlook the fact that such unities are abstractions, and are to be treated as such.

70. Now it is very noticeable that the mind is prone to deal with abstractions in strange disregard of the concretes they express; so that men who candidly admit their inability to explain some of the elementary vital processes, profess to have a theory of Life, and unable to explain the cardinal facts and laws of light, heat, electricity, etc., are confident in their assertions respecting

the Cosmos, its origin and purpose. No wonder, then, that, instead of laboriously ascertaining what is known of the properties of Matter, they imagine that they can by a facile exercise of divination detect the nature of Matter. Instead of classifying the observed phenomena, they classify their conceptions without verifying them, without ascertaining in how far these conceptions represent actual experiences. It is obvious that a perfect theory of Matter must embrace and explain all material phenomena; and it is equally obvious that this cannot be done unless all the phenomena are inductively established and classified.*

71. Let us, by way of illustration, consider what progress would have been effected in electrical science, if, instead of observing, analyzing, and classifying the facts, men had continued for centuries speculating about. what Electricity was in itself, what its hidden nature was. Since a special group of material phenomena could not thus have been brought within our grasp, still less could the universal group, if philosophers had continued deducing conclusions from unverified conceptions, instead of observing and registering all our experiences, and ascending to generalized Notations of these, which in turn served as bases for speculative generalizations to be subsequently verified, so that, from this mass of observation and inference hypotheses might be formed re

* In the words of Sir W. Thomson, "Every addition to knowledge of the properties of matter supplies the naturalist with new instrumental means for discovering and interpreting the phenomena of nature, which in their turn afford foundations for fresh generalizations, bringing gains of permanent value into the great storehouse of philosophy." This is not apparently the opinion of metaphysicians; it is, at any rate, not their practice, for the "People's Friend" Marat could say with justice, "Les philosophes sans règles, sans principes, au lieu d'examiner ce qu'ils voulaient connoître, définirent tout d'un coup ce qu'ils ne connaissaient pas. De l'Homme, ou des Principes et des Loix de l'Influence de l'Âme sur le Corps. Amsterdam, 1775. Pref., p. iv.

specting the extra-sensible conditions. Our only progress has been effected by an extension of known properties and known laws, under the guidance of new inferences, and their verification. The Method has been that of a constant extension of the sensible into the extra-sensible, and a subsequent reduction of inference to Feeling or Intuition. Hypothesis and Deduction have been largely employed; but it is a fatal error to suppose that Deduction, even the most plausible, can, unaided, extend positive knowledge; while the deductions of metaphysicians have, for the most part, been without an inductive basis. I have already pointed out the fallacy of pure Deduction being competent to reach truth à priori (PROBLEM III. § 66), but the importance of the topic makes me recur to it here in presence of the metaphysical discussions respecting Matter.

72. The triumphs of Deduction are seen in the mathematical treatment of Physics, where equations of the same. form are found applicable to very dissimilar groups of phenomena, such, for example, as Heat and Electricity: that is to say, the relation between the cause and the effect is expressed by equations of the same kind, so that when a problem is once solved in one group, the solution is translated into the terms of the other. Thus is established the congruity of symbols, which is the aim of science. But this is possible only so far as the relations formulated are sufficiently general to be theoretically identical: no sooner are other and heterogeneous relations introduced under the symbols, than the deduction becomes vitiated. For instance, "Potential, in electrical science, has the same relation to Electricity that Pressure in Hydrostatics has to Fluid, or that Temperature in Thermodynamics has to Heat. Electricity, Fluids, and Heat all tend to pass from one place to another, if the Potential, Pressure, or Temperature is greater

in the first place than in the second. A fluid is certainly a substance, heat is as certainly not a substance; so that, though we may find assistance from analogies of this kind in forming clear ideas of formal electrical relations, we must be careful not to let the one or the other analogy suggest to us that electricity is either a substance like water, or a state of agitation like heat.” * Nay, more, we must be careful not to conclude that even the phenomena of conduction will be in all respects the same in their results, since experiment may disclose striking diversities. Thus if a conducting body be suspended within a closed conducting vessel, and the vessel be charged with electricity, the body will show no signs of electrification either when within the vessel or on being removed from it; whereas the body included in a vessel which is heated will become of the same temperature as the vessel, and will on being removed retain this heat for some time. So indispensable is Verification even when the deductions seem most guaranteed.

73. In the preceding chapter we have been dealing with sensibles, with Matter as it is given in Feeling; and although we have from time to time found ourselves compelled to pass beyond the sensible limit, compelled to interpret sensible perceptions by ideal conceptions, still our main purpose has been the classification and elucidation of the observed phenomena. We have now to pass the limit of Observation, and enter on that of Speculation. We quit the record of Feeling, and inquire into the nature of the Extra-sensible. This inquiry may also be strictly scientific, closely as it borders on the region of Metempirics. We shall no longer be dealing directly with the facts of Feeling, but explaining them by indirect inferences and constructions.

74. The theory of gases perfected by Clausius and

* CLERK MAXWELL, Electricity and Magnetism, 1873, I. 74.