Imágenes de páginas
PDF
EPUB

Mammalian series.

They are to the full as numerous and as weighty differences as those which separate any two allied orders of quadrupeds, and are much more striking than those which separate some of the orders. Temporarily, however, and for the sake of argument, we may admit that these differences are not such as to entitle man to a position in the class of Mammals more select than that of a mere family of an order containing also the monkeys; and we may next ask if these characters do indeed constitute the zoological definition of man.

All naturalists are agreed that the value of any given classification depends upon the extent to which it is "natural." That is to say, the value of any given classification depends entirely upon the extent to which it is grounded upon and takes into account all the characters of the objects classified. It is very easy and often very convenient to classify objects by some one character alone; and the more superficial and conspicuous such a character may be, the better will it be fitted for such a purpose. Classifications founded upon such single characters, ignoring the totality of the objects classified, are, however, stigmatized as "artificial," and have been now universally and finally abandoned by every science which has cut its leading-strings, and has attained to the power of walking alone.

The question, then, inevitably arises: Does the above classification embrace all the characters of man? Or, does it ignore some of his most important peculiarities, and thus brand itself as "artificial"? We do not think that two answers ought to be possible to such a question, and we may take an imaginary illustration in support of this assertion. Suppose naturalists were to unearth in some remote corner of the globe an assemblage of beings possessing all the physical characters of man-large-brained, erect, bipedal, and hairless-but wholly destitute of his higher characters, speaking no articuate language, using no tools, building

no habitations, ignorant of fire, and showing no mental powers higher than those of the monkeys. It may be said that such an assemblage of animals is an impossible conception, and that an animal with a human brain would of necessity exhibit the psychical characters of man. This, however, is begging the question, and we are not bound to accept such an assumption in an imaginary case. Let us suppose, then, that naturalists suddenly stumble upon such a race as the above -how are they to be classified? Are they to be placed unreservedly and unequivocally in the same group as Homo sapiens, or are they to be regarded as merely a peculiar group of the Apes, or may we consider them as transitional between man and the monkeys? Assuredly, those who maintain that man's zoological position is to be wholly determined by his anatomical, or so-called "zoological" characters, would be logically compelled to group this race with the family of "articulately-speaking men," and that, too, without any line of demarcation. Many naturalists, however, would declare that such beings, in spite of their anatomical structure were not men, and we venture to think that this conclusion would be backed by the common sense and innate feeling of the world at large.

We think, then, that any naturalist is justified, as a scientific man, in maintaining that all classifications of man by his anatomical characters alone are artificial, and as such are indefensible. Such classifications do not embrace the totality of man's organization, and can not, therefore, be natural. If, as most people would readily admit, a race of beings possessing man's physical structure, but not endowed with his mental characters, is not truly to be regarded as human, then man's zoological definition must be made to include something more than his mere physical and anatomical structure. That something is man's mental and moral constitution; and we repeat our belief that any naturalist is justified, without disparagement to either

his knowledge or his ability, in maintaining that man's psychical peculiarities are as much an integral factor of his zoological definition as his physical structure, or perhaps more so. We will not allow that mental characters do not come under the head of "zoological" characters, and we should be perfectly willing to have this principle applied to the whole series of the Mammals. If mental characters are characters at all, surely they serve to distinguish the objects which exhibit them, quite as strongly as the grosser and more palpable characters to be derived from anatomical structure; and if so, they certainly must be taken into account in any classification which pretends to be "natural." We are far from saying that, even in man, due prominence should not be given to the details of the physical organization. Such characters are necessarily almost the only available ones in the Mammals generally, and are undoubtedly of the greatest importance even in man himself. Few, also, would be disposed to doubt that the mental organization of an animal must be most closely and intimately correlated with its physical strucIf we knew thoroughly the laws of such correlation, then it would be amply sufficient to classify all animals, including man, solely by anatomical characters; for then the statement of the physical structure would instantly furnish the instructed naturalist with the key to the mental status of any given animal. It is needless to say, however, that in place of possessing any such thorough knowledge, our ignorance of the laws of correlation may fairly be characterized as profound. Indeed, when we come to the brain, and the nervous system in general, we may be said to know literally nothing as to the correlation of structure and function. We do not even know enough to secure assent to the very probable supposition that here a very minute and apparently trivial difference in structure may be correlated with an almost immeasurable difference in mental power.

ture.

It seems, however, that no more completely retrograde step has been taken in the whole of this discussion than the importation into this subject of the question whether the mind be the product of the brain, or whether the brain be merely the organ of the mind. It is difficult to conceive of any dis-cussion more hopelessly idle and futile than this; since it is clear that the premises at present at our command will allow of either conclusion being logically arrived at. We know the material structure which we call the brain, we recognize certain phenomena which we call mental, and we have every reason to be certain that there is the closest connection between the brain of any animal and its mental phenomena. We have not, however, any means of determining with absolute certainty what is the nature of this connection; and if it be one of effect and cause, we have no single datum to determine which is effect and which is cause. We know the sequence of phenomena; we do not know which phenomenon precedes the other in point of time. It is just as scientific, therefore, and just as logical, to believe that the brain exists as an effect of the mind, as it is to believe that "the brain secretes mind as the liver secretes bile." The one opinion has no scientific advantage over the other; and it is at present very difficult to see how we can arrive at any absolutely unassailable conclusion upon this point, any more than upon many other kindred questions. In the meanwhile, at any rate, either opinion is open to the impartial and unbiassed reasoner, and each individual will adopt one or other view, just as he may be guided by the general tendency of his mind and the general drift of his studies.

It may not, perhaps, be out of place to point out here, that the discussion as to the nature of life and its connection with matter, rests upon a precisely similar basis. We recognize certain phenomena which we call "vital," as being exclusively manifested by living beings; and we recognise further that

these phenomena are never manifested except by certain forms of matter, or, it may be, by no more than a single form of matter. It is clear therefore, that there is the closest connection between vital phenomena and the "matter of life." It is a bold conclusion, however, from these premises to deduce that life is the result of living matter, or one of its inherent properties. We know the succession of phenomena, but we know no more; and it is just as logical to conclude that living matter is the result of vital forces. This may seem to be a digression as regards the matter in hand; but in truth the two questions are very intimately connected, and a final decision in one case would almost inevitably determine the other.

We have, then, arrived so far in our argument as the assertion that man's psychical characters ought to be taken into account in the determination of his zoological position; and that, indeed, they ought to have at least as much weight as his anatomical structure in deciding this question. We are aware that many eminent naturalists would deny this assertion in toto; but the question is at present certainly one of individual opinion, and no argument, as we shall see, can be carried out on such a subject without some such assertion on one side or the other. Allowing, then, this assertion to pass, it becomes clear that the question of man's zoological position will turn ultimately upon the value which we attach to his mental characters; since man does not differ much in anatomical structure from the Anthropoid apes, but certainly does differ greatly from them as regards his psychical manifestations. Mr. Darwin, indeed, tacitly admits this; for he is obliged to base his argument wholly upon the assumption that the mental phenomena, moral and intellectual, exhibited by man differ from those of animals in degree only and not in kind. This assumption we may examine in detail, but it is well to bring forward one point prominently beforehand. If, as asserted by Mr. Darwin, man's psychi

cal phenomena differ from those of monkeys or other Mammals in degree only, then by the logical necessity of Mr. Darwin's own hypothesis there is no mental difference, other than that of degree, between man and the lowest of the Vertebrate sub-kingdom, the degraded little fish known as the Lancelet. As Mr. Darwin has further explicitly declared his belief in a genetic connection between the Lancelet and those degraded Molluscs, the Ascidians, it follows that man's mental constitution does not differ in kind from that of a Sea-squirt. So far Mr. Darwin himself leads us, and we may rest contented here, but it would not be difficult to show that his theory leads us logically to the inevitable conclusion that man's intellectual and moral endowments do not differ in kind from those of a Sponge, or any still lower Invertebrate. It is quite true that it might be difficult to demonstrate any mental phenomena in a Sponge, at least we are not aware that any have hitherto been recorded. Still, all man's faculties must be present in the Sponge in an undeveloped condition; for Haeckel assures us that it is not difficult to show how the Polypes have descended from the Sponges, and the former have decided relationships to the lower Molluscs, whilst the last undoubtedly have connections amongst the fishes, and so, further, up to "the noblest work of God." No one, however, will be disposed to deny Mr. Darwin the possession of the "courage of his opinions," and it is possible he would not shrink from believing that all man's faculties are present, in germ, in plants, since the animal and vegetable kingdoms probably spring from a common progenitor.

Mr. Darwin prefaces his argument by the remark that "no classification of the mental powers has been universally accepted," without apparently recognizing how enormously such a state of things detracts from the value of any comparison of the mental constitution of man and the lower animals. Such a comparison is wholly within the domain.

mother for her new-born offspring," and speaks of these as being instincts which man has in common with the lower animals.— Now, if an instinct be an inherited habit, it is clear that there must have been a time in the history of each instinct when the instinct was not; for the term "habit" implies a previous absence of habit. But, we cannot suppose it possible that there was ever a time in the history of man, or of any other species of animal in which sexual love did not exist; nor could we properly speak of the "habit " of self-preservation. Mr. Darwin, again, seems to us to have by no means happily evaded the difficulty of the peculiar instincts of sexless animals, such as worker-bees, and ants, which have no offspring, and which, therefore, cannot transmit acquired or inherited habits. The instincts, for example, of a worker-ant are wholly different from those of the queen, and yet the worker is the offspring of the latter. The instincts, again, of a soldier-ant differ both from those of the worker and from those of the queen, and yet the soldier is both neuter and the immediate offspring of the queen. We have, therefore, the queen, with one set of instincts, giving origin to other queens with the same instincts, and to workers and soldiers, each with peculiar instincts, and each incapable of transmitting these instincts by heredity.— To say that these instincts appear to arise

of Psychology, and Psychology has not yet agreed about her fundamentals! Psychology, in fact, as a science, if it can fairly be said to exist at all, is certainly as yet in extremest infancy. Surely this ought to induce caution in the acceptance of any solution of one of the profoundest problems to the consideration of which Psychology can at any time be called. Admitting that we are tolerably well acquainted with the constitution of the human mind, though assuredly we have yet much both to learn and unlearn even on this head, there still remains the fact that we are almost totally ignorant of the mental organization of animals. We have, of course, been able to observe and record a greater or less number of authentic mental phenomena, as exhibited by the lower animals. We know, however, absolutely nothing of the source and nature of these phenomena, and it is begging the whole question to assume that the mental phenomena of animals arise from a source of the same kind as those of man, merely because man himself thinks he can detect in their mental acts a certain similarity to his own. We should bear in mind, then, from the very outset, that the comparison between the mental powers of man and those of the lower animals is a comparison between one very partially known quantity, and another about which hardly anything is known and still less is universally agreed.-"through the natural selection of variations Taking the lower animals first, we meet with the very general belief, even at the present day, that the mental actions of animals are mainly, if not exclusively, to be ascribed to what is vaguely called "instinct." Hardly any two writers have succeeded in agreeing as to what we are to understand by instinct; but we may here look at two definitions.Mr. Darwin knows perfectly well what he means by instinct, for he understands by this term "inherited habit." In spite, however, of the perfect clearness of this definition, Mr. Darwin speaks of the instincts of "selfpreservation, sexual love, the love of the

of simpler instinctive actions" hardly seems to render matters much more perspicuous, and certainly deprives Mr. Darwin's definition of instinct of almost its entire value.

At the very best, however, the proposition that instinct is "inherited habit" is an assumption, and is one in support of which no evidence of weight has been brought forward. That habits may become instinctive is certain, and it is equally certain that these habits may be transmitted in the way of inheritance. It by no means follows from this that all instincts were originally habits, nor does there seem any probability in such

a view. The late Professor Goodsir, on the other hand, one of the most profound anatomists that Britain has ever produced, defines instinct as "a collective term applied to those laws in virtue of which the psychical endowments of the animal are so adjusted in reference to its organism with its functions, and to all the necessary and contingent circumstances in its existence, as to enable them to work together harmoniously in the adaptation of means to ends, without self-consciousness." In other words, instinct is a collective term applied to those laws in virtue of which each species of animal acts in a definite and unvarying manner under given circumstances, its actions being performed "with unerring accuracy and without previous training."

reason comparable to that of man, neverthe-
less believed that it could not well be denied
"that there is in the constitution of the
brute an essence which is not material." He
believed that this immaterial principle is the
essential element of the animal, "failing
which, the body of the animal would have
had no existence," and that it is in this im-
material principle that "the instinctive con-
sciousness of the animal subsists.” He be-
lieved, however, that the immaterial princi-
ple of the brute is destitute of self-conscious-
ness and, therefore, necessarily incapable
of "intellectual movement;" so that "its
so-called intellectual processes resolve them-
selves into mere suggestive acts.
Its so-
called thoughts, or trains of thought, are
merely individual acts of objective con-

of its instinct. These acts of objective consciousness may be immediate—that is, induced by the actual presence of the object; or they may be mediate that is reproductions of acts of objective consciousness, through the memory or imagination.”

Whatever definition of instinct be ultim-sciousness connected by the determining law ately adopted, few of those who have studied the subject will be disposed to deny that animals, in some cases, exhibit phenomena which cannot rightly be called instinctive. Mr. Darwin concludes that animals exhibit emotions essentially similar to those of man: maternal affection, jealousy, love of praise, shame, wonder, curiosity, imitation, attention, memory, imagination, and reason; and the evidence, as regards most of these, will no doubt bear him out in his assertion. We may remark, however, en passant that it is an assumption that dreaming is an act of the imagination, and no other proof is adduced that animals possess this faculty beyond the fact that they certainly dream. As regards the faculty of reason, few unprejudiced observers will probably deny its possession to the brutes, though there are doubt less some to whom such an allowance would be distasteful. In reality, however, no stronger assistance could be given to the Darwinian theory of the descent of man than by an obstinate adherence to the untenable doctrine that animals possess nothing higher than mere blind and mechanical instincts.

The late Prof. Goodsir, indeed, whilst denying to the brutes the possession of a

It is not necessary that we should accept all the views of this profound observer upon this subject; but the belief that animals possess a much higher mental organization than that usually allotted to them is one which is constantly gaining ground, and which certainly in no way interferes with the belief that man's mental powers are sui generis and wholly distinct in kind from those of animals. The admission of this cuts away from the Darwinian theory one of its strongest supports, for it deprives the evidence to be obtained from domesticated animals of almost all its weight. If animals possess a mental organization peculiar to each species, then there is no reason whatever why such an organization should not be influenced and improved by man. We know that we can influence and improve the physical organization of a horse or a dog, without thinking that we could convert either into an elephant or a monkey. We may believe

« AnteriorContinuar »