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"THE LAW OF SUBSTANCE"

I shall now endeavour to exhibit the way in which Professor Haeckel proceeds to expound his views, and for that purpose shall extract certain sentences from his work, The Riddle of the Universe; giving references to the sixpenny translation, now so widely circulated in England, in order that they may be referred to in their context with ease. To scientific men the exaggeration of statement will in many cases be immediately obvious; but in the present state of general education it will often be necessary to append a few comments, indicating, as briefly as possible, wherein the statement is in excess of ascertained fact, however interesting as a guess or speculation; wherefore it must be considered illegitimate as a weapon wherewith to attack other systems, so far as they too are equally entitled to be considered reasonable guesses at truth.

The central scientific doctrines upon which Professor Haeckel's philosophy is founded appear to be two—one physical, the other biological. The physical doctrine is what he calls "the Law of Substance"—a kind of combination of the conservation of matter and the conservation of energy: a law to which he attaches extraordinary importance, and from which he draws momentous conclusions. Ultimately he seems to regard this law as almost axiomatic, in the sense that a philosopher who has properly grasped it is unable to conceive the negative. A few extracts will suffice to show the remarkable importance which he attaches to this law:—

"All the particular advances of physics and chemistry yield in theoretical importance to the discovery of the great law which brings them to one common focus, the 'law of substance.' As this fundamental cosmic law establishes the eternal persistence of matter and force, their unvarying constancy throughout the entire universe, it has become the pole-star that guides our monistic philosophy through the mighty labyrinth to a solution of the world-problem" (p. 2).

"The uneducated member of a civilised community is surrounded with countless enigmas at every step, just as truly as the savage. Their number, however, decreases with every stride of civilisation and of science; and the monistic philosophy is ultimately confronted with but one simple and comprehensive enigma—the 'problem of substance'" (p. 6).

"The supreme and all-pervading law of nature, the true and only cosmological law, is, in my opinion, the law of substance; its discovery and establishment is the greatest intellectual triumph of the nineteenth century, in the sense that all other known laws of nature are subordinate to it. Under the name of 'law of substance' we embrace two supreme laws of different origin and age—the older is the chemical law of the 'conservation of matter,' and the younger is the physical law of the 'conservation of energy.' It will be self-evident to many readers, and it is acknowledged by most of the scientific men of the day, that these two great laws are essentially inseparable" (p. 75).

"The conviction that these two great cosmic theorems, the chemical law of the persistence of matter and the physical law of the persistence of force, are fundamentally one, is of the utmost importance in our monistic system. The two theories are just as intimately united as their objects—matter and force or energy. Indeed, this fundamental unity of the two laws is self-evident to many monistic scientists and philosophers, since they merely relate to two different aspects of one and the same object, the cosmos" (p. 76).

"I proposed some time ago to call it the 'law of substance,' or the 'fundamental cosmic law'; it might also be called the 'universal law,' or the 'law of constancy,' or the 'axiom of the constancy of the universe.' In the ultimate analysis it is found to be a necessary consequence of the principle of causality" (p. 76).

I criticise these utterances below, and I also quote extracts bearing on the subject from Professor Huxley in Chapter IV.; but meanwhile Professor Haeckel is as positive as any Positivist, and runs no risk of being accused of Solipsism:—

"Our only real and valuable knowledge is a knowledge of nature itself, and consists of presentations which correspond to external things." … "These presentations we call true, and we are convinced that their content corresponds to the knowable aspect of things. We know that these facts are not imaginary, but real" (p. 104).

He also tends to become sentimental about the ultimate reality as he perceives it, and tries to construct from it a kind of religion:—

"The astonishment with which we gaze upon the starry heavens and the microscopic life in a drop of water, the awe with which we trace the marvellous working of energy in the motion of matter, the reverence with which we grasp the universal dominance of the law of substance throughout the universe—all these are part of our emotional life, falling under the heading of 'natural religion'" (p. 122).

"Pantheism teaches that God and the world are one. The idea of God is identical with that of nature or substance. … In pantheism, God, as an intra-mundane being, is everywhere identical with nature itself, and is operative within the world as 'force' or 'energy.' The latter view alone is compatible with our supreme law—the law of substance. It follows necessarily that pantheism is the world-system of the modern scientist" (p. 102).

"This 'godless world-system' substantially agrees with the monism or pantheism of the modern scientist; it is only another expression for it, emphasising its negative aspect, the non-existence of any supernatural deity. In this sense Schopenhauer justly remarks:

"'Pantheism is only a polite form of atheism. The truth of pantheism lies in its destruction of the dualist antithesis of God and the world, in its recognition that the world exists in virtue of its own inherent forces. The maxim of the pantheist, 'God and the world are one,' is merely a polite way of giving the Lord God his congé'" (p. 103).

Thus we are led on, from what may be supposed to be a bare statement of two recent generalisations of science—first of all to regard them as almost axiomatic or self-evident; next, to consider that they solve the main problem of the universe; and, lastly, that they suffice to replace the Deity Himself.

To curb these extravagant pretensions it is only necessary to consider soberly what these physical laws really assert.

Conservation of Energy.

Take first the conservation of energy. This generalisation asserts that in every complete material system, subject to any kind of internal activity, the total energy of the system does not change, but is subject merely to transference and transformation, and can only be increased or diminished by passing fresh energy in or out through the walls of the system. So far from this being self-evident, it required very careful measurement and experimental proof to demonstrate the fact, for in common experience the energy of a system left to itself continually to all appearance diminishes; yet it has been skilfully proved that when the heat and every other kind of product is collected and measured, the result can be so expressed as to show a total constancy, appertaining to a certain specially devised function called "energy," provided we know and are able to account for every form into which the said energy can be transformed by the activity going on. A very important generalisation truly, and one which has so seized hold of the mind of the physicist that if in any actual example a disappearance or a generation of energy were found, he would at once conclude either that he had overlooked some known form and thereby committed an error, or that some unknown form was present which he had not allowed for: thereby getting a clue which, if followed up, he would hope might result in a discovery.

But the term "energy" itself, as used in definite sense by the physicist, rather involves a modern idea and is itself a generalisation. Things as distinct from each other as light, heat, sound, rotation, vibration, elastic strain, gravitative separation, electric currents, and chemical affinity, have all to be generalised under the same heading, in order to make the law true. Until "heat" was included in the list of energies, the statement could not be made; and, a short time ago, it was sometimes discussed whether "life" should or should not be included in the category of energy. I should give the answer decidedly No, but some might be inclined to say Yes; and this is sufficient as an example to show that the categories of energy are not necessarily exhausted; that new forms may be discovered; and that if new forms exist, until they are discovered, the law of conservation of energy as now stated may in some cases be strictly untrue; just as it would be untrue, though partially and usefully true, in the theory of machines, if heat were unknown or ignored. To jump, therefore, from a generalisation such as this, and to say, as Professor Haeckel does on page 5, that the following cosmological theorems have already been "amply demonstrated," is to leap across a considerable chasm:—

"1. The universe, or the cosmos, is eternal, infinite, and illimitable.

"2. Its substance, with its two attributes (matter and energy), fills infinite space, and is in eternal motion.

"3. This motion runs on through infinite time as an unbroken development, with a periodic change from life to death, from evolution to devolution.

"4. The innumerable bodies which are scattered about the space-filling ether all obey the same 'law of substance'; while the rotating masses slowly move towards their destruction and dissolution in one part of space, others are springing into new life and development in other quarters of the universe."

Most of this, though in itself probable enough, must, when scientifically regarded, be rated as guess-work, being an overpressing of known fact into an exaggerated and over-comprehensive form of statement. Let it be understood that I am not objecting to his speculations, but only pointing out that they are speculations.

The conservation of energy is a legitimate enough generalisation: we do not really doubt its conservation and constancy when we admit that we are not yet sure of having fully and finally exhausted the whole category of energy. What we do grant is, that it may hereafter be possible to discover new forms; and when new forms are discovered, then either the definition may have to be modified, or else the detailed statement at present found sufficient will have to be overhauled. But after all, this is not specially important: the serious mistake which people are apt to make concerning this law of energy is to imagine that it denies the possibility of guidance, control, or directing agency, whereas really it has nothing to say on these topics; it relates to amount alone. Philosophers have been far too apt to jump to the conclusion that because energy is constant, therefore no guidance is possible, so that all psychological or other interference is precluded. Physicists, however, know better; though unfortunately Tyndall, in some papers on Miracles and Prayer, thoughtlessly adduced the conservation of energy as decisive. This question of "guidance" is one of great interest, and I emphasise the subject further on, especially in Chapter IX.

Conservation of Matter.

Take next the "conservation of matter"—which means that in any operation, mechanical, physical, or chemical, to which matter can be subjected, its amount, as measured by weight, remains unchanged; so that the only way to increase or diminish the weight of substance inside a given enclosure, or geometrically closed boundary, is to pass matter in or out through the walls.

This law has been called the sheet-anchor of chemistry, but it is very far from being self-evident; and its statement involves the finding of a property of matter which experimentally shall remain unchanged, although nearly every other property is modified. To superficial observation nothing is easier than to destroy matter. When liquid—when dew, for instance—evaporates, it seems to disappear, and when a manuscript is burnt it is certainly destroyed: but it turns out that there is something which may be called the vapour of water, or the "matter" of the letter, which still persists, though it has taken rarer form and become unrecognisable. Ultimately, in order to express the persistence of the permanent abstraction called "matter" clearly, it is necessary to speak of the "ultimate atoms" of which it is composed, and to say that though these may enter into various combinations, and thereby display many outward forms, yet that they themselves are immutable and indestructible, constant in number and quality and form, not subject to any law of evolution; in other words, totally unaffected by time.

If we ask for the evidence on which this generalisation is founded, we have to appeal to various delicate weighings, conducted chiefly by chemists for practical purposes, and very few of them really directed to ascertain whether the law is true or not. A few such direct experiments are now, indeed, being conducted with the hope of finding that the law is not completely true; in other words, with the hope of finding that the weight of a body does depend slightly on its state of aggregation or on some other physical property. The question has even been raised whether the weight of a crystal is altogether independent of its aspect: the direction of its plane of cleavage with reference to the earth's radius; also, whether the temperature of bodies has any influence on their weight; but on these points it may be truly said that if any difference were discovered it would not be expressed by saying that the amount of matter was different, but simply that "weight" was not so fundamental and inalienable a property of matter as has been sometimes assumed; in which case it is clear that there must be a more fundamental property to which appeal can be made in favour of constancy or persistency or conservation. Now the most fundamental property of matter known is undoubtedly 'inertia'; and the law of conservation would therefore come to mean that the inertia of matter was constant, no matter what changes it underwent. But, then, inertia is not an easy property to measure—very difficult to measure with great accuracy: it is in practice nearly always inferred from weight; and in terms of inertia the law of conservation of matter cannot be considered really an experimental fact; it is, strictly speaking, a reasonable hypothesis, an empirical law, which we have never seen any reason to doubt, and in support of which all scientific experience may be adduced in favour.

It is possible, however, to grant to Professor Haeckel—not positively, but for the sake of argument, and giving him the benefit of our present ignorance—that it is unlikely that matter in its lowest denomination can by us be created or destroyed. For, although it is now pretty well known that atoms of matter are not the indestructible and immutable things they were once thought (seeing that, although we do not know how to break them up, they are liable every now and then themselves to break up or explode, and so resolve themselves into simpler forms), yet it can be granted that these simpler forms are likewise themselves atoms, in the same sense, and that if they break up they will break up likewise into atoms: or ultimately, it may be, into those corpuscles or electrons or electric charges, of which one plausible theory conjectures that the atoms of matter are really composed.

Supposing an atom thus broken up into electrons, its weight may possibly have disappeared. We simply do not know whether weight is a property of the grouping called an atom, or whether it belongs also to the individual ingredients or corpuscles of that atom. There is at present no evidence. But whether weight has disappeared or not, it is quite certain, for definite though rather recondite theoretical reasons, that the inertia would not have disappeared; and accordingly it may be held, and must be held in our present state of knowledge, that the constancy of fundamental material still holds good, even though the atoms are resolved into electric charges—an amount of destruction never contemplated by those chemists and physicists who promulgated the doctrine of the conservation of matter.

Electrical Theory of Matter.

But then, on the electrical theory of matter, even inertia is not the thoroughly constant property we once thought it. It is a function of velocity for one thing, and when speeds become excessive the inertia of matter rises perceptibly in value. The fact that it would rise in value by a calculable amount, and that the rise would be perceptible when the speed of motion approached in value to within, say, a tenth of the velocity of light, was predicted mathematically;¹ and now, strange to say, it has recently become possible to observe and actually measure the increase of inertia experimentally, and thus to confirm the electrical theory not only as qualitatively or approximately true, but as completely and quantitatively accurate. A remarkable achievement all this! of quite modern times, which has not excited the attention it deserves—save among physicists.

But even this is not all that can be said as to the fluctuating character of that fundamental material quality "inertia." It appears possible, if electrons approach too near each other, so as to encroach on each other's magnetic field as they move, that then their inertia may fall in value during the time they are contiguous. No experimental fact has yet suggested this at present: it is improbable that even in the tightest combinations they ever really approach close enough to each other to make the effect appreciable in the slightest degree; still, strictly speaking, the inertia of matter is a known mathematical function of the distance of electrons apart, compared with their size, as well as of their absolute speed through the ether; and hence it may be found to vary from either of two distinct reasons. Nevertheless, even this variation would not be expressed as a failure in the conservation of matter, though there is now no single material property that can be specified as really and genuinely constant. So long as the electric centres of strain, or whatever they are—so long as the electric charges themselves—continue unaltered, we should prefer to say that at least the basis of matter was fundamentally conserved.

Further than this, however, we cannot go; and to say, as Professor Haeckel says, that the modern physicist has grown so accustomed to the conservation of matter that he is unable to conceive the contrary, is simply untrue. Whatever may be the case in real fact, there is no question with respect to the possibility of conception. The electrons themselves must be explained somehow; and the only surmise which at present holds the field is that they are knots or twists or vortices, or some sort of either static or kinetic modification, of the ether of space—a small bit partitioned off from the rest and individualised by reason of this identifying peculiarity. It may be that these knots cannot be untied, these twists undone, these vortices broken up; it may be that neither artificially nor spontaneously are they ever in the slightest degree changed. It may be so, but we do not know; and it is quite easy to conceive them broken up, the identity of the electron lost, its substance resolved into the original ether, without parts or individual properties. If this happened, within our ken, we should have to confess that the properties of matter were gone, and that hence everything that could by any stretch of language be called "matter" was destroyed, since no identifying property remained. The discovery of such an event may lie in the science of the future; it would be an epoch-making event in the history of science, but no physicist would be upset by it—perhaps not even surprised; nor would any one have good reason to be astonished if the correlative phenomenon occurred, and under certain conditions some knots or strains were some day caused in the ether, which had not been previously there; and so "matter," or the foundation of matter, artificially produced. In other words, the destruction and the creation of matter are well within the range of scientific conception, and may be within the realm of experimental possibility.

Persistence of the Existent.

Is there, then, no meaning in the conception which Professor Haeckel and others have so enthusiastically formulated, and which certainly commends itself to every one as representing in some sense a genuine truth, whether it be called a "law of substance" or whatever it be called? There does seem a certain plausibility in the idea, pure guess or assumption though it be, that anything which really and fundamentally exists, in a serious and untrivial and non-accidental sense, can be trusted not suddenly to go out of existence and leave no trace behind. In other words, there seems some reason to suppose that anything which actually exists must be in some way or other perpetual; that real existence is not a capricious and changing attribute: arbitrary collocations and accidental relations may and must be temporary, but there may be in each a fundamental substratum which, if it can be reached, will be found to be eternal. I develop this idea further in the sequel. This is, at any rate, what Professor Haeckel was evidently groping after, as many others have groped before him, and the nature of this fundamental persistent entity or entities (for we must not assume without proof that there is only one: there may be several, and at any rate their ultimate unification may be a still further advanced and more transcendental problem) may with some appropriateness be called 'the problem of the universe,' since it is clearly the problem of existence. Professor Haeckel thinks he has solved the problem, grasped the fundamental reality, and found it to be matter and energy and nothing else; though why he chooses to regard matter and energy as one thing instead of two is not perfectly plain to me, nor, I venture to say, is it really plain to him.

Making the assumption, then, that there is something, or that there are several things, to be discovered, which may thus have the most fundamental property, viz., persistent immutable existence, the 'problem' has resolved itself into the discovery of what these things actually are. It will not do to jump at some object and assume that that is it.

A multitude of things obviously perish, thereby showing themselves to be trivial or accidental arrangements, according to our hypothesis. A flame is extinguished and dies, a mountain is ultimately ground into sand by the slow influence of denudation, a planet or a sun may lose its identity by encounter with other bodies. All these are temporary collocations of atoms; and it appears now that an atom may break up into electric charges, and these again may some day be found capable of resolving themselves into pristine ether. If so, then these also are temporary, and in the material universe it is the ether only which persists—the Ether with such states of motion or strain as it eternally possesses—in which case the Ether will have proved itself the material substratum and most fundamental known entity on that side.

But are we to conclude, therefore, that nothing else exists? that the existence of one thing disproves the existence of others? The contention would be absurd. The category of life has not been touched in anything we have said so far; no relation has been established between life and energy, or between life and ether. The nature of life is unknown. Is life also a thing of which constancy can be asserted? When it disappears from a material environment is it knocked out of existence, or is it merely transferred to some other surroundings, becoming as difficult to identify and recognise as are the gases of a burnt manuscript or the vapour of a vanished cloud? Is it a temporary trivial collocation associated with certain complex groupings of the atoms of matter, and resolved into nothingness when that grouping is interfered with? or is it something immaterial and itself fundamental, something which uses these collocations of matter in order to display itself amid material surroundings, but is otherwise essentially independent of them? (This idea is expanded in Chapters VI. to X., and see note at end of present chapter.)

Professor Haeckel would answer this question with a contemptuous negative; and the treatment which he would thus give to life he would also extend to mind and consciousness, to affection, to art, to poetry, to religion, and all the other facts of experience to which in the process of evolution humanity has risen: I say he would answer the question, whether these had any real existence other than as a necessary concomitant of a sufficiently complex material aggregate, with a contemptuous negative; but I challenge him to say by what right he gives that answer. His speculation is that all these properties are nascent and latent in the material atoms themselves, that these have the potentiality of life and choice and consciousness, which we perceive in their developed combinations. As a speculation this is legitimate; but the only answer that can by science legitimately be given at the present time is the answer given by du Bois-Reymond, ignoramus, we do not know.

Scientifically we do not; and for a man of science to pretend, or to assert in a popular treatise, that we do, is essentially and seriously to mislead. (See Chapter VII. below.) It may even be a question whether the assertion of entire ignorance at the present time is completely appropriate, whether we have not some positive evidence against Professor Haeckel's contention. I believe that we have; and though I may acquiesce in an assertion of present ignorance, I am not at all willing to accept the next sentence of Professor du Bois-Reymond's answer, and to say ignorabimus, we never shall know.

The matter seems to me within the legitimate lines of scientific inquiry, and it is unwise to attempt prediction, especially negative prediction, or to attempt to close the door to the future developments of knowledge.

But I am content to say for the present that from the point of view of strict science it is not yet possible to give any positive answer to these questions; that they must await the progress of discovery. It becomes a question of some interest, therefore, how it is possible for Professor Haeckel and for others of his school to have arrived at the idea not only that a scientific answer can be given, but that already it has been given, and that they know distinctly what it is.

Note on the Word "Life."

Until a term is accurately defined, and even afterwards for some purposes, it is permissible to use a word of large significance in more than one sense. Thus the word "light" may be considered a psychological term, denoting a certain sensation, or a physiological term, signifying the stimulus of certain specialised nerve-endings, or a physical term, expressing briefly an electromagnetic wave-disturbance in the ether. I am using the word "life" in a quite general sense, as is obvious, for if it be limited to certain metabolic processes in protoplasm—which is the narrowest of its legitimate meanings—what I have said about its possible existence apart from matter would be absurd. It may be convenient to employ the word "vitality" for this limited sense; but so far as I know, there is no general consensus of usage, and the context must suffice to show a friendly reader the connotation intended.