[[p. 1]] When primeval man first rose above the brutes from which he was developed; when, by means of his superior intellect, he had acquired speech and the use of fire; and more especially when his reasoning and reflecting faculties caused him to ask those questions which every child now asks about the world around it--what is this? and why is that?--he would, for the first time, perceive and wonder at the great contrast between the living and the not-living things around him.

    He would first observe that the animals which he caught and killed for food, though so unlike himself outwardly, were yet very like his fellow-men in their internal structure. He would see that their bony framework was almost identical in shape and in substance with his own; that they possessed flesh and blood, that they had eyes, nose, and ears; that presumably they had senses like his own, sensations like his own; that they lived by food and drink as he did, and yet were in many ways so different. Above all, he would soon notice how inferior they were to himself in intellect, inasmuch as they never made fires, never used any kind of tools or weapons; and that, although many of them were much stronger than he was, yet his superiority in these things, and in making traps or pitfalls to capture them, showed that he was really their superior and their master.

    Gradually, probably very slowly, he would extend these observations to all the lower forms of life, even when both externally and internally he could find no resemblance whatever to his own body; to crabs and winged insects, to [[p. 2]] land-shells and sea-shells, and ultimately to everything which by moving and feeding, by growing and dying, showed that it was, like himself, alive. Here, probably, he would rest for awhile, and it might require several generations of incipient philosophers to extend the great generalisation of "life" to that omnipresent clothing of the earth's surface produced by the infinitely varied forms of vegetation. The more familiar any phenomenon is--the more it is absolutely essential to our life and well-being--the less attention we pay to it and the less it seems to need any special explanation. Trees, shrubs, and herbs, being outgrowths from the soil, being incapable of any bodily motion and usually exhibiting no indications of sensation, might well have been looked upon as a necessary appendage of the earth, analogous to the hair of mammals or the feathers of birds. It was probably long before their endless diversity attracted much notice, except in so far as the fruits or the roots were eatable, or the stems or foliage or bark useful for huts or clothing; while the idea that there is in them any essential feature connecting them with animals and entitling them to be classed all together as members of the great world of life would only arise at a considerably later stage of development.

    It is, in fact, only in recent times that the very close resemblance of plants and animals has been generally recognised. The basis of the structure of both is the almost indistinguishable cell; both grow from germs; both have a varied life-period from a few months to a maximum of a few hundreds of years; both in all their more highly organised forms, and in many of their lower types also, are bisexual; both consist of an immense variety of distinct species, which can be classified in the same way into higher and higher groups; the laws of variation, heredity, and the struggle for existence apply equally to both, and their evolution under these laws has gone on in a parallel course from the earliest periods of the geological record.

    The differences between plants and animals are, however, equally prominent and fundamental. The former are, with few exceptions, permanently attached to the soil; they absorb nourishment in the liquid or gaseous state only, and their tissues are almost wholly built up from inorganic [[p. 3]] matter, while they give no clear indications of the possession of sensation or voluntary motion. But notwithstanding these marked differences, both animals and plants are at once distinguished from all the other forms of matter that constitute the earth on which they live, by the crowning fact that they are ALIVE; that they grow from minute germs into highly organised structures; that the functions of their several organs are definite and highly varied, and such as no dead matter does or can perform; that they are in a state of constant internal flux, assimilating new material and throwing off that which has been used or is hurtful, so as to preserve an identity of form and structure amid constant change. This continuous rebuilding of an ever-changing highly complex structure, so as to preserve identity of type and at the same time a continuous individuality of each of many myriads of examples of that type, is a characteristic found nowhere in the inorganic world.

    So marvellous and so varied are the phenomena presented by living things, so completely do their powers transcend those of all other forms of matter subjected to mechanical, physical, or chemical laws, that biologists have vainly endeavoured to find out what is at the bottom of their strange manifestations, and to give precise definitions, in terms of physical science, of what "life" really is. One authority (in Chambers's Encyclopædia) summed it up in three words--"Continuity, Rhythm, and Freedom,"--true, perhaps, but not explanatory; while Herbert Spencer declared it to be--"the definite combination of heterogeneous changes, both simultaneous and successive, in correspondence with external co-existences and sequences." This is so technical and abstract as to be unintelligible to ordinary readers.

    The following attempt at a tolerably complete definition appears to sum up the main distinctive characters of living things:--

    Life is that power which, primarily from air and water and the substances dissolved therein, builds up organised and highly complex structures possessing definite forms and functions: these are preserved in a continuous state of decay and repair by internal circulation of fluids and gases; they reproduce their like, go through various phases of youth, [[p. 4]] maturity, and age, die, and quickly decompose into their constituent elements. They thus form continuous series of similar individuals; and, so long as external conditions render their existence possible, seem to possess a potential immortality.

    The characteristics here enumerated are those which apply to both plants and animals, and to no other forms of matter whatever. It is often stated that crystals exhibit the essential features of some of the lowest plants; but it is evident that, with the exception of the one item of "definite form," they in no way resemble living organisms. There is no doubt, however, that crystals do exhibit definite forms, built up by the atoms or molecules of various elements or compounds under special conditions. But this takes us a very small way towards the complex structure and organisation of living things.

    There are still people who vaguely believe that "stones grow," or that "all matter is really alive," or that, in their lowest and simplest forms, the organic and the inorganic are indistinguishable. For these ideas, however, there is not a particle of scientific justification. But the belief that "life" is a product of matter acted upon by chemical, electrical, or other physical forces, is very widely accepted by men of science at the present day, perhaps by a majority. It is, in fact, held to be the only scientific view, under the name of "monism"; while the belief that "life" is sui generis, that it is due to other laws than those which act upon dead or unorganised matter, that it affords evidence of an indwelling power and guidance of a special nature, is held to be unscientific--to be, in fact, an indication of something akin to, if not actually constituting, an old-fashioned superstition. That such a view is not uncommon may be shown by a few extracts from scientific writers of some eminence.

    The well-known German biologist Ernst Haeckel, in a recent work, makes the following statement:

    "The peculiar phenomenon of consciousness is not, as Du Bois-Reymond and the dualistic school would have us believe, a completely transcendental problem; it is, as I showed thirty-three years ago, a physiological problem, and, as such, must be reduced to the phenomena of physics and chemistry" (The Riddle of the Universe, p. 65, translated by Joseph M'Cabe).

    "The two fundamental forms of substance, ponderable matter and ether, are not dead, and only moved by extrinsic force, but they are endowed with sensation and will (although, naturally, of the lowest grade); they experience an inclination for condensation, a dislike of strain; they strive after the one and struggle against the other" (p. 78).

    In these two passages we have a self-contradiction in meaning if not in actual words. In the first, he reduces consciousness to phenomena of physics and chemistry; in the second he declares that both matter and ether possess sensation and will. But in another passage he says he conceives "the elementary psychic qualities of sensation and will which may be attributed to atoms to be unconscious" (p. 64).

    It is this quite unintelligible theory of matter and ether possessing sensation and will, being able to strive and struggle and yet be unconscious, which enables him to say:

    "We hold with Goethe that matter cannot exist and be operative without spirit, nor spirit without matter. We adhere firmly to the pure, unequivocal monism of Spinoza: Matter, or infinitely extended substance, and Spirit (or Energy), or sensitive and thinking substance, are the two fundamental attributes, or principal properties, of the all-embracing essence of the world, the universal substance" (p. 8).

    Here we have yet another contradiction--that the thinking infinite substance is unconscious! This leads to his theory of the "cell-soul," which is the origin of all consciousness, but which is itself unconscious. This he reiterates emphatically. He tells us that at a certain grade of organisation "consciousness has been gradually evolved from the psychic reflex activity, and now conscious voluntary action appears" (p. 41). Along with these strange conceptions, which really explain nothing, he propounds his "Law of Substance" as the one great foundation of the universe. This is merely another name for "persistence of force" or "conservation of energy," yet at the end of the chapter expounding it he claims that, "in a negative way, it rules out the three central dogmas of metaphysics--God, freedom, and immortality" (p. 83). A little further on he again states his position thus:

    [[p. 6]] "The development of the universe is a monistic mechanical process, in which we discover no aim or purpose whatever; what we call design in the organic world is a special result of biological agencies; neither in the evolution of the heavenly bodies, nor in that of the crust of the earth do we find any trace of a controlling purpose--all is the result of chance."

    Then, after discussing what is meant by chance, he concludes:

    "That, however, does not prevent us from recognising in each 'chance' event, as we do in the evolution of the entire cosmos, the universal sovereignty of nature's supreme law, the law of substance" (p. 97).

    Again, he defines his position still more frankly:

    "Atheism affirms that there are no gods or goddesses, assuming that god means a personal, extra-mundane entity. 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" (p. 103).

    These vague and often incomprehensible assertions are interspersed with others equally unprovable, and often worded so as to be very offensive to religious minds. After having put forth a host of assertions as to a possible future state, which exhibit a deplorable ignorance of the views of many advanced thinkers in all the Churches, he says:

   "Our own 'human nature' which exalted itself into an image of God in an anthropistic illusion, sinks to the level of a placental mammal, which has no more value for the universe at large than the ant, the fly of a summer's day, the microscopic infusorium, or the smallest bacillus. Humanity is but a transitory phase of the evolution of an eternal substance, a particular phenomenal form of matter and energy, the true proportion of which we soon perceive when we set it on the background of infinite space and eternal time" (p. 87).

    The writings of Haeckel, the extremely dogmatic and assertive character of which have been illustrated in the preceding quotations, have had an immense influence on many classes of readers, who, when a man becomes widely known as a great authority in any department of science, accept him as a safe guide in any other departments on [[p. 7]] which he expresses his opinions. But the fact is that he has gone altogether out of his own department of biological knowledge, and even beyond the whole range of physical science, when he attempts to deal with problems involving "infinity" and "eternity." He declares that "matter," or the material universe, is infinite, as is the "ether," and that together they fill infinite space, and that both are "eternal" and both "alive." None of these things can possibly be known, yet he states them as positive facts. The whole teaching of astronomy by the greatest astronomers to-day is that the evidence now at our command points to the conclusion that our material universe is finite, and that we are rapidly approaching to a knowledge of its extent. Our yearly increasing acquaintance with the possibilities of nature leads us to the conclusion that in infinite space there may be other universes besides ours; but if so, they may possibly be different from ours--not of matter and ether only. To assert the contrary, as Haeckel does so confidently, is surely not science, and very bad philosophy.

    He further implies, and even expressly states, that there is no spirit-world at all; that if life exists in other worlds it must be material, physical life; and that, as all worlds move in cycles of development, maturity, and destruction, all life must go through the same phases--that this has gone on from all eternity past, and will go on for all eternity to come, with no past and no future possible, but the continual rise of life up to a certain limited grade, which life is always doomed to extinction. And it is claimed that this eternal succession of futile cycles of chance development and certain extinction is, as an interpretation of nature, to be preferred to any others; and especially to those which recognise mind as superior to matter, which see in the development of the human intellect the promise of a future life, and which have in our own day found a large mass of evidence justifying that belief.

    With Professor Haeckel's dislike of the dogmas of theologians, and their claims to absolute knowledge of the nature and attributes of the inscrutable mind that is the power within and behind and around nature, many of us have the greatest sympathy; but we have none with his unfounded [[p. 8]] dogmatism of combined negation and omniscience, and more especially when this assumption of superior knowledge seems to be put forward to conceal his real ignorance of the nature of life itself. He evades altogether any attempt to solve the various difficult problems of nutrition, assimilation, and growth, some of which, in the case of birds and insects, I shall endeavour to set forth as clearly as possible in the present volume. As Professor Weismann well puts it, the causes and mechanism by which it comes about that the infinitely varied materials of which organisms are built up "are always in the right place, and develop into cells at the right time," are never touched upon in the various theories of heredity that have been put forward, and least of all in that of Haeckel, who comes before us with what he claims to be a solution of the Riddle of the Universe.

Huxley on the Nature and Origin of Life

    Although our greatest philosophical biologist, the late Professor T. H. Huxley, opposed the theory of a "vital force" as strongly as Haeckel himself, I am inclined to think that he did so because it is a mere verbal explanation instead of being a fundamental one. It conceals our real ignorance under a special term. In his Introduction to the Classification of Animals (1869), in his account of the Rhizopoda (the group including the Amœbæ and Foraminifera), he says:

    "Nor is there any group in the animal kingdom which more admirably illustrates a very well-founded doctrine, and one which was often advocated by John Hunter, that life is the cause and not the consequence of organisation; for in these lowest forms of animal life there is absolutely nothing worthy of the name of organisation to be discovered by the microscopist, though assisted by the beautiful instruments that are now constructed. . . . It is structureless and organless, and without definitely formed parts. Yet it possesses all the essential properties and characters of vitality. Nay, more, it can produce a shell; a structure, in many cases, of extraordinary complexity and most singular beauty.

    "That this particle of jelly is capable of guiding physical forces in such a manner as to give rise to those exquisite and almost mathematically-arranged structures--being itself structureless and without permanent distinction or separation of parts--is to my mind a fact of the profoundest significance" (p. 10).

    "Is the case any way changed when carbonic acid, water, and nitrogenous salts disappear, and in their place, under the influence of pre-existing living protoplasm, an equivalent weight of the matter of life makes its appearance?" (p. 53).

    But here we have the words I have italicised introduced which were not in the previous statement; and these are of fundamental importance considering the tremendous conclusion he goes on to draw from them--"that the thoughts to which I am now giving utterance are the expression of molecular changes in that matter of life which is the source of our other vital phenomena." At the end of the lecture he says that "it is of little moment whether we express the phenomena of matter in terms of spirit, or the phenomena of spirit in terms of matter--each statement has a certain relative truth." But he thinks that in matters of science the materialistic terminology is in every way to be preferred.

    This is vague and unsatisfactory. It is not a mere question of terminology; but his statement that "thought is the expression of molecular change in protoplasm" is a mere begging of the whole question, both because it is absolutely unproved, and is also inconsistent with that later and clearer statement that "life is the cause of organisation"; but, if so, life must be antecedent to organisation, and can only be conceived as indissolubly connected with spirit and with thought, and with the cause of the directive energy everywhere manifested in the growth of living things.

    [[p. 10]] In the present volume I am endeavouring to arrive at a juster conception of the mystery of the Life-World than that of Professor Haeckel, and by a very different method. I shall endeavour to give a kind of bird's-eye sketch of the great life-drama in many of its broader and less-known phases, showing how they all form parts of the grand system of evolution, through adaptation to continuous changes in the outer world. I shall also endeavour to penetrate into some of the less trodden paths of nature-study, in order to exhibit the many indications that exist of the preparation of the Earth for Man from the remotest eons of geological time.