TWO BOOKS ON EVOLUTION.* THE non-scientific world is probably almost

nauseated at this time by the ever-recurrent subject of Evolution. It is, however, one of such interest in itself ; its growth has been so rapid, and its relation—whether legitimate or not—to other topics of still greater moment seems so intimate, and the thoughts connected

• The Evolution of Han: a Popular Exposition of the Principal Points of Human ihstogeny and Phylogeny. From the German of Ernst Haeckel, Professor in the University of Jena. ,tc. London: C. Regan Paul and Co. 1879.

Habit and Intelligence. By Joseph John Murphy. Second Edition, thoroughly Revised, and mostly Rewritten. London: Macmillan and Co. 1879.

with it have penetrated so deeply into the minds of men, that we cannot avoid devoting some space to the consideration of works

which deal with it with any measure of novelty and vigour. We have now before us two somewhat bulky treatises,—one a translation of the last edition of The Evolution of Man, by the well-known Professor Haeckel, of Jena ; and the other by Mr. Murphy, the ingenious author of The Scientific Bases of Faith. Both these books are professedly intended more for general than for strictly scientific uses, Mr. Murphy's science being admittedly, to a great extent, second-hand, though he is a well-informed student of the science of the day ; while Pro- fessor Haeckel's work, minute and systematic as its details are,

is rather that of a philosophical speculator on science, than of a practical student of science in the paths of observation and experiment.

Professor Haeckel is celebrated as the apostle of Darwinian evolution carried to its utmost limits, both as relates to the scientific hypothesis itself, and to the metaphysical or ontological results to which, in his view, it necessarily leads. In many things his evolutionism is much more thorough and his belief is much more unhesitating than that of Mr. Darwin, and his tone very different indeed from the tone of that most modest and laborious investigator whose disciple he professes to be. He looks upon the Evolution controversy as the real battle-ground between priestcraft and retrogression on the one hand, and the "modern struggle for culture" on the other. He indulges in expressions of contempt and scorn for many of those who differ from him, among biologists the chief objects of his contro- versial enmity being certain evolutionists less thoroughgoing than himself, amongst others, Du Bois Reymoud, whose address at Leipzig, some five years ago, created so much interest ; "the English Jesuit, Mivart," as he terms him ; Vogt, and Kolliker ; and had his book been of slightly later date, he would have been obliged to add the very considerable name of Virchow. When he deals with the theological aspect of his subject, we are reminded more of the sceptical writers of the last century, than of the more earnest and reverent philosophical doubters of our own age. Professor Haeckel's work is written in an admirably clear style, and the statement of scientific details, illustrated by excel-

lent engravings and diagrams, is such that any attentive reader, however little conversant with such things, can have no difficulty in understanding it. It begins with a very able sketch of the history of the Evolution theory from its earliest hints in the writings of Aristotle, to its reappearance in something like its present form in the speculations of Lamarck, and thence to

the modern researches of Mr. Wallace and Mr. Darwin. In eulogising the latter, and alluding to his grandfather, the

Darwin of the Zoonomia, Haeckel's words are amusingly characteristic of the school to which the author belongs " Erasmus Darwin transmitted to his grandson Charles, according to the law of latent transmission (atavism), certain molecular move- ments of the cells in the ganglia of his powerful brain, which had not made their appearance in his son Robert. The fact is of great im- terest in relation to the remarkable law of atavism which Charles Darwin himself has so well discussed."

It is not our business to discuss the purely scientific data on which Haeckel founds his opinions ; suffice it to say that there are some particulars in regard to which he has, we doubt not, seen cause to alter his opinion since this book was written, but they are not of sufficient magnitude to affect the general results. The details are, of course, mainly embryological. The develop- ment of the individual is to him the evolution of the race com- pressed into a brief period of time, and with the aid of Morpho- logy, that marvellous science which has made such rapid strides in our own day, in the hands of Oken, our own Owen, and and others, and even received a powerful impetus from the scientific imagination of Germany's greatest poet, the light thrown on the probabilities of Phylogeny by the actual facts of Ontogeny is such, that we cannot wonder at the intense interest which Evolutionism now excites, and the extent to which it has been accepted. Haeckel's view of the more immediate progeni- tors of man having been anthropoid apes, not, however, of any existing species, is common to him and all the rest of the school; behind them he sees a vista of pouched animals of the type still existing in Australia—then of inferior vertebrata (Amphibia and mud-fishes)—until the genealogy reaches through "chords animals" and primitive worms, back to the primary jelly-specks, or Monera, which have life with- out organisation, in the usual sense of the term. Birds mollusca, insects, and crustacea, &c., are out of the line of descent altogether. The apparently tremendous leap from

worms to vertebrata is bridged over by what is looked upon as the sole remnant of what may have been a numerous and varied family, the little mud-inhabiting Amphioxus. The analysis of this creature, so obscure and yet so important in a theoretical point of view, and that of the still humbler ascidian or sea-squirt, is well worthy of study, by those who have not already become acquainted with it in the writings of other evolutionists. This portion of the work, and the exposition of the " Gastrwa theory," are especially interesting.

Professor Haeckel sees no difficulty in believing that the two principles of heredity and adaptation, taken in his own sense of absolutely blind forces, modifying each other, and of course making myriads of failures before they produce that which can survive have evolved the infinite variety of species which have ex- isted, and at present exist. He carries the influence of natural selection beyond what, if we understand his more recent views, Mr. Darwin himself contends. The haste, we had almost said eager- ness, with which he ignores rather than meets the many difficul- ties which have been so often stated, is very remarkable. Closely connected with this negative peculiarity is the thorough agnosti- cism (and this is a mild term) of such passages as the following,— referring to the very curions fact, long familiar to everybody, of the existence throughout nature of rudimentary organs, of no use to their possessor, but sometimes of actual injury, or at least danger (as the cmcal appendage in man), but which perform a, necessary function in other species,—a fact which is, of course, strongly suggestive of the general hypothesis of evolution ; and certainly the theory of descent goes far to account for it, or, at least, to throw light on how it has come to pass. In Professor Haeckel's view, such facts are totally subversive of Teleology,— by implication, of all Theism :—

"The very ancient fable of the all-wise plan, according to which the Creator's hand has ordained all things with wisdom and under- standing,' the empty phrase about the 'purposive plan of structure,' is in this way completely disproved. Stronger arguments can hardly be provided against the customary teleology, or doctrine of design, than the fact that all more highly developed organisms possess such rudimentary organs.' The favourite phrase, the moral ordering of the world,' is also shown in its true light by these dysteleological facts. Thus viewed, the moral ordering of the world' is evidently a beau- tiful poem, which is proved to be false by the actual facts. None but the idealist scholar, who closes his eyes to the real truth, or the priest, who tries to keep his spiritual flock in ecclesiastical leading strings, can any longer tell the fable of the moral ordering of the world. It exists neither in nature nor in human life, neither in natural history nor in the history of civilisation. The terrible and ceaseless struggle for existence' gives the real impulse to the blind course of the world. A moral ordering and a 'purposive plan' of the world can only be visible, if the prevalence of an immoral rule of the strongest and un- designed organisation is entirely ignored."

Speaking of Agassiz and his admitted Theism, he says :— "This great American was in reality gifted with too much

genius actually to believe in the truth of the mystic nonsense which he preached. Crafty calculation, and well-judged reliance on the want of understanding of his credulous followers, can alone have given him courage to pass the juggler's pieces of his anthropomorphic creation as true coin."

And here is Professor Haeckel's view of materialism and spiritualism :—

" The opponents of the doctrine of Evolution are very fond of branding the monistic philosophy grounded upon it as Materialism,' by confusing philosophical materialism with the wholly different and censurable moral materialism. Strictly, however, our 'Monism' might as accurately or as inaccurately be called spiritualism, as materialism. The real materialistic philosophy asserts that the vital phenomena of nature, like all other phenomena of nature, are effects or products of matter. The other, opposite extreme, spiritualistic philosophy, asserts, on the contrary, that matter is the product of motive force, and that all material forms are produced by free forces, entirely independent of the matter itself Both views are dualistic, and we hold them both to be equally false. A contrast to both views is presented by the monistic philosophy which can as little believe in force without matter as in matter without force. It is only necessary to reflect on this for a time, from a strictly scientific stand-point, to find that, on close examination, it is impossible clearly to represent the one without the other."

Before making any remark on these views, which are only those of a now very large school of thought in every country in Europe, and especially in Germany, we must advert to the other work which is now before us.

Mr. Murphy is a decided evolutionist, in the more restricted sense of having arrived at the conclusion that all organic beings have been developed from anteriorly existing lower and more simple forms. His grounds of belief are not different from those of others, but he cannot discover in heredity and adapta- tion, in the sense in which these words are generally used, a sufficient cause for the production of the variety of organisms

which now exists. He urges strongly the difficulties arising from fixity of character, from structures which are utterly useless, unless accompanied (as they are in numerous instances) by other structures in quite unconnected parts of the same organism ; and above all, from the facts of structure in anticipa- tion offunction, and of organs which are eminently advantageous when fully developed, but which could have been of no avail during the long period which, on the showing of the extreme advocates of natural selection themselves, they must have required to attain useful dimension. He quotes and dwells upon Mr. Wallace's statement of the argument drawn from the human brain, which, in the case of savages, attains, on an average, a development which may be represented by the number 26, that of average civilised men being 32, while that of the anthropoid apes is only 10. He contends that the brain of the savage has been developed far beyond the functions which it performs, its proportion being, so far as actual cerebration goes, much nearer that of the ape and further from that of the philosopher than these figures would indicate. His brain is, therefore, in anticipation of function. Neither natural selection nor any other unintelli- gent agency can account for any 'structure which is thus in anticipation of its actual requirements, and, therefore, not im- mediately useful. The idea is suggestive of a surplusage of power,—of an instrument beyond the wants of its possessor. There is an excellent chapter to the same effect, on the rate of variation, and the geological time required for the evolution which has actually taken place, assuming no other causes than those commonly called Darwinian. In this discussion he founds partly on the well-known mathematical conclusions of Sir W.. Thomson, in reference to the time required for the cooling of the globe.

Convinced of the truth of the general doctrine of Evolution,

but unable to adopt the blind agencies of accidental variation and survival of the fittest as anything more than subordinate modifying causes, and profoundly alive to the evidence of de- sign in the organic world generally, and on the other hand, deeply impressed by the so-called dysteleological facts of useless rudimentary structures, which appear inimical to the hypothesis of a directly creative agency, Mr. Murphy seems to have taken refuge and to find relief in a doctrine which appears to be the main raison d''gtre of his book. This he calls the doctrine of "Habit and Intelligence." "All vital actions," he says, "tend

to repeat themselves." Habitual action is seen in all formative, in all motor, and in all mental detions, except such of the latter as are purely voluntary. All characters tend to become hereditary, all are in some degree variable, and par- ticular characters may acquire a habit of varying. Habit and variation, however, with the controlling influence of external conditions, will not account for the evolution of species whereby the most highly organised vegetables and animals have been derived from the first vitalised brit unorganised germs. An Intelligent Power is required, acting through and controlling the unintelligent forces of habit and variation, "just as all the vital forces act through and control the inorganic ones." This brings into play that "Intelligence" which, in Mr. Murphy's view, supplements and controls the blind agencies of habit and variation. There is, he says, a formative intelligence, which guides growth and organisation ; a motor intelligence, residing in reflex, automatic, and instinctive motion. In all these, the in- telligence is unconscious; in voluntary motion, it is partly con- scious; in mental action, it has become conscious. Organising and mental intelligence are identical, differing only in the element of consciousness. Habit is conservative, intelligence is progressive, and works with a definite view to the future. Mr. Murphy, in common with Professor Haeckel, professes Monism. "The mind of man is not distinct from the material world in the midst of which it is placed, but is the highest pro- duct of the forces of that world." It may be doubted how far his concluding sentence is in harmony with this statement :—

"The question, what point in the development either of the indi- vidual or the race is that where the spiritual nature has come in, cannot be answered ; but it is not an important one to answer. It is, however, in accordance with all the analogies of creation, if the Creative Pdwer which at the beginning created matter, and afterwards gave it life, finally, when the action of that life had developed the bodily frame and the instinctive mental power of man, completed the work by breathing into man a breath of higher and spiritual hfe."

These two books are typical representatives of the two more obvious schools of thought which spring from the Evolution doctrine. The first represents a class of minds already predis-

_ posed to a Materialistic view of the Universe, and to the re- ception of those beliefs only which have, or appear to have, their foundation in the data of sensation and external perception, while they ignore some of the equally credible dicta of human consciousness. They receive the arguments in favour of the omnipotence of natural selection as equally powerful with those which support the general hypothesis of evolution, and to them the scheme of mechanical and unintelligent creation seems to be complete. They are fond of speaking of the evolution doctrine as an "induction," which it is not, although the universality of the coincidence between embryotic forms in the higher and adult forms in the lower ranks of organic beings, on which the phylogenetic hypothesis is founded, is, no doubt, a good general- isation. It is, perhaps, the most remarkable instance in the history of human thought of a purely scientific inquiry, and that in a purely material region, furnishing food for so-called philosophical conclusions.

Mr. Murphy, on the other hand, represents the more cautious thinker, who, while he accepts the mass of probable evidence in favour of Evolution in the general sense, cannot see in it data for Atheistic conclusions. He is unable to shut his eyes to the signs of purpose in Nature. The very fact of upward progress which is implied in evolution itself, seems to him at variance with the pessimist tone of those who see nothing in the Universe but a direful struggle for existence ; and the gradual superaddition of the higher mental powers, and of the faculty (however elaborated) of recognising and loving the True, the Good, and the Beautiful,—faculties the nobility of which is admitted by the most thorough-going Haeckelian—seems to him not to be accounted for by the mere survival of the fittest. A race possessing such mental faculties as should fit it for subduing the -earth by mechanical means might be so evolved, but it is hard to see how brains suited for the cultivation of art and philosophy should be victorious in the struggle. These developments suggest to him the action of an intelligent First Cause, which has chosen gradually and systematically to work out the pro- gress of our race onwards and upwards.

Mr. Murphy's doctrine of "unconscious intelligence" is not new or peculiar to him. Traces of it are to be found in other physiological writings. It seems at first sight to relieve us from a difficulty. It seems to reconcile the complexity of structure, and the evident design in the growth and evolution of organisms, with the idea of a single Cause, without necessitating the elirect agency of the Divine Will in every minute molecular change, and it appears to throw upon this hypothetical inter- mediate agent or demiourgos the burden of those rudimentary and useless structures of which we hear so much. But is not this slOking, in place of solving, a difficulty ? Mr. Murphy says that there is no greater absurdity in "unconscious intelligence" than in "unconscious force," and that if it is necessary to resolve formative powers into the direct agency of the Divine Will, it is equally so in the case of gravitation, or any other dynamic force. But the idea of endowing vital formative energy with intelligence, in order to account for its varied and evidently purposive action, without crediting it with consciousness, is something very like a contradiction. It is outside of the consciousness of the being in whose organism it works, but it is difficult to see how it can represent intelligence without a consciousness of its own. If it means the intelligence of its Divine Author, by which intelligence it has been so arranged that it shall work so as to conduce to His purposes, there is no objection stateable, on the ground of contradiction, or on any other ground, except the non-necessity of the hypothesis. But as the ordinary physi-cal forces of inorganic nature also work for a purpose, though by far more simple rules and far more simple results, we do not see why they also should not be called "intelligences." Mr. Murphy protests that he is not a Pantheist, and on the other hand, he would deny that his doctrine is a incipient Hegelianism, though it does look somewhat like it. He evidently believes in a Deity personal and, in every sense, prior to Nature.

The whole question mainly depends on what is the correct idea of Causation. To a disciple of Professor Haeckel, it ought to mean nothing but invariable sequence ; and the giving of such names as Heredity and Adaptation to the leading features of such sequences is merely a convenient way of expressing the result of a generalisation by a single word. To such persons, no difficulty occurs ; they are merely ignoring much that ought not to be ignored. The whole Cosmos is to them the result of forces which are blind and authorless, and has at length

emerged, such as we find it, from the scramble. Indeed, in strict logic, they ought not to speak even of forces, but only of pheno- mena. If, on the other hand, the ideas of causation and dynamic action are indissolubly linked in our minds (and. beyond our minds, in such questions, we cannot go), and origi- nate in the analogy to our own consciousness of power in voluntary action, the " intelligence " which is interposed between the First Cause and the phenomena of organic growth, or any other phenomena, must be a conscious intelligence, to which is entrusted, so to speak, a volition like that which we possess ; and there is no reason why, in place of one Derniourgos, there should not be many, each regulating that immediately beneath him.

Be all this as it may, and whatever may be the ultimate fate of the Evolution doctrine, so far from being incompatible either with Theism, or with the continued existence of man after the death of that which we now regard as the totality of his organic frame, we believe it to be more strictly compatible with both than with the atheistic hypothesis. Even theoretical Monism may be so put as not to involve our extinction at that crisis, for the true definition of the one entity does not imply that in certain conditions it may not lose all rela- tion to those few external senses which we happen at pre- sent to possess. In any view, there can be no doubt that the Evolution hypothesis has proved a most import- ant stimulus to the systematic and careful culture of certain branches of biology. The good which it has done, and what- ever element of truth is in it, will be permanent, the non-essen- tials of the doctrine having dropped off, while whatever adverse influence it may have had on philosophy and theology will pass away.