In all cases, however, where intelligence has been a co-operating factor, this intelligence has lapsed so soon as the activity became truly instinctive.

From the co-operation of the factors it is almost impossible to give examples which shall illustrate the exclusive action of any one. The following table must therefore be regarded as indicating the probable predominance of the factor indicated:—

In speaking of the instinct of caterpillars spinning cocoons as unintelligent, I am regarding the final purpose of the activity. Intelligence may very possibly have come into play in modifying the details of procedure. In giving the drumming of snipe as an example of unintelligent activities furthered by selection, I am assuming that it has a sexual import, and that the activity correlated with a narrowing of the tail-feathers was not, in its inception, intelligently performed with the object of exciting sexual appetence in the hen. The case of the ants of Siam is given by Mr. Romanes,[JO] on the authority of Lonbière, who says "that in one part of that kingdom, which lies open to great inundations, all the ants made their settlements upon trees; no ants' nests are to be seen anywhere else." Now, this modification of habits may have been the result of intelligence; or it may have been forced upon the ants by circumstances. The floods drove them on to the trees; the instinctive impulse to build a settlement was imperative; hence the settlement had to be formed on the trees, because the ground was flooded. The difficulty of ascertaining whether intelligence has or has not been a factor is simply part of the inherent difficulty of comparative psychology—a difficulty on which sufficient stress has already been laid in an earlier chapter.

The great majority of the instinctive activities of animals have arisen through a co-operation of the factors, and it is exceedingly difficult in any individual case to assign to the factors their several values.

And here we must once more notice that the separation off of the instinctive activities from the other activities of animals is merely a matter of convenience in classification. In the living organism the activities—automatic actions, reflex actions, incompletely and perfectly established instincts, habits, and intelligent activities—are unclassified and commingled. They are going on at the same time, shading the one into the other, untrammelled by the limits imposed by a scientific method of treatment.

Once more, too, we must notice that the activities of animals are essentially the outcome and fulfilment of emotional states. When the emotional sensibility is high, the resulting activities are varied and vigorous. As we have before seen, this high state of emotional sensibility is correlated with a highly charged and sensitive condition of the organic explosives elaborated by the plasmogen of the cells. After repose, and at certain periodic times, this state of exalted sensibility is apt to occur. It is exemplified in the so-called instinct of play, which manifests itself in varied activities in the early morning, in early life, and in the returning warmth of spring—at such times, in fact, as the life-tide is in full flood.

But perhaps the activities which result from a highly wrought state of sensibility are best seen at the periodic return of sexual appetence or impulse in animals of various grades of life and intelligence. Many organisms, at certain periods of the year, and in presence of their mates, are thrown into a perfect frenzy of sexual appetence. The love-antics of birds have been so frequently described that I will merely quote from Darwin[JP] Mr. Strange's account of the satin bower-bird: "At times the male will chase the female all over the aviary, then go to the bower, pick up a gay feather or a large leaf, utter a curious kind of note, set all his feathers erect, run round the bower, and become so excited that his eyes appear ready to start from his head; he continues opening first one wing, and then the other, uttering a low, whistling note, and, like the domestic cock, seems to be picking up something from the ground, until at last the female goes gently towards him." Instances might be quoted from almost all classes of the animal kingdom. Many fish display "love-antics," for example, the gay-suited, three-spine stickleback, whose excitement is apparently intense. Newts display similar activities. Even the lowly snail makes play with its love-darts (spiculæ amoris), practical tangible darts of glistening carbonate of lime. Mr. George W. Peckham has recently described[JQ] the extraordinary "love-dance" of a spider (Saitis pulex). "On May 24 we found a mature female, and placed her in one of the larger boxes; and the next day we put a male in with her. He saw her as she stood perfectly still, twelve inches away; the glance seemed to excite him, and he at once moved towards her; when some four inches from her he stood still, and then began the most remarkable performances that an amorous male could offer to an admiring female. She eyed him eagerly, changing her position from time to time, so that he might be always in view. He, raising his whole body on one side by straightening out the legs, and lowering it on the other by folding the first two pairs of legs up and under, leaned so far over as to be in danger of losing his balance, which he only maintained by sidling rapidly towards the lowered side. The palpus, too, on this side was turned back to correspond to the direction of the legs nearest it. He moved in a semicircle for about two inches, and then instantly reversed the position of the legs, and circled in the opposite direction, gradually approaching nearer and nearer to the female. Now she dashes towards him, while he, raising his first pair of legs, extends them upward and forward as if to hold her off, but withal slowly retreats. Again and again he circles from side to side, she gazing towards him in a softer mood, evidently admiring the grace of his antics. This is repeated until we have counted a hundred and eleven circles made by the ardent little male. Now he approaches nearer and nearer, and when almost within reach whirls madly around and around her, she joining and whirling with him in a giddy maze. Again he falls back and resumes his semicircular motions, with his body tilted over; she, all excitement, lowers her head and raises her body, so that it is almost vertical; both draw nearer; she moves slowly under him, he crawling over her head, and the mating is accomplished."

It can scarcely be doubted that such antics, performed in presence of the female and suggested at sight of her, serve to excite in the mate sexual appetence. If so, it can, further, scarcely be doubted that there are degrees of such excitement, that certain antics excite sexual appetence in the female less fully or less rapidly than others; yet others, perhaps, not at all. If so, again, it can hardly be questioned that those antics which excite most fully or most rapidly sexual appetence in the female will be perpetuated through the selection of the male which performs them. This is sexual selection through preferential mating. And, I think, the importance of these activities, their wide range, and their perfectly, or at any rate incompletely instinctive nature, justifies me in emphasizing this factor in the origin of instinctive activities. It has hitherto, I think, not received the attention it deserves in discussions of instinct.

A few more words may here be added to what has already been said on the influence of intelligence on instinct. The influence may be twofold—it may aid in making or in unmaking instincts. We have seen that instincts may be modified through intelligent adaptation. A little dose of judgment, as Huber phrased it, often comes into play. The cell-building instinct of bees is one which is remarkably stereotyped; and yet it may be modified in intelligent ways to meet special circumstances. When, for example, honey-bees were forced to build their comb on the curve, the cells on the convex side were made of a larger size than usual, while those on the concave side were smaller than usual. Huber constrained his bees to construct their combs from below upwards, and also horizontally, and thus to deviate from their normal mode of building. The nest-construction of birds, again, may be modified in accordance with special circumstances. And, perhaps, it is scarcely too much to say that, whenever intelligence comes on the scene, it may be employed in modifying instinctive activities and giving them special direction.

Now, suppose the modifications are of various kinds and in various directions, and that, associated with the instinctive activity, a tendency to modify it indefinitely be inherited. Under such circumstances intelligence would have a tendency to break up and render plastic a previously stereotyped instinct. For the instinctive character of the activities is maintained through the constancy and uniformity of their performance. But if the normal activities were thus caused to vary in different directions in different individuals, the offspring arising from the union of these differing individuals would not inherit the instinct in the same purity. The instincts would be imperfect, and there would be an inherited tendency to vary. And this, if continued, would tend to convert what had been a stereotyped instinct into innate capacity; that is, a general tendency to certain activities (mental or bodily), the exact form and direction of which is not fixed, until by training, from imitation or through the guidance of individual intelligence, it became habitual. Thus it may be that it has come about that man, with his enormous store of innate capacity, has so small a number of stereotyped instincts.

But while intelligence, displayed under its higher form of originality, may, in certain cases, lead to all-round variation, tending to undermine instinct and render it less stereotyped, intelligence, under its lower form of imitation, has the opposite tendency. For young animals are more likely to imitate the habits of their own species than the foreign habits of other species, and such imitation would therefore tend towards uniformity.

Imitation is probably a by no means unimportant factor in the development of habits and instincts. Mr. A. R. Wallace, in his "Contributions to the Theory of Natural Selection," contends that the nest-building habit in birds is, to a large extent, kept constant by imitation. The instinctive motive is there, but the stereotyped form is maintained through imitation of the structure of the nest in which the builders were themselves reared. Mr. Weir, however, writing to Mr. Darwin, in 1868, says in a letter, which Mr. Romanes quotes,[JR] "The more I reflect on Mr. Wallace's theory, that birds learn to make their nests because they have themselves been reared in one, the less inclined do I feel to agree with him.... It is usual with canary-fanciers to take out the nest constructed by the parent birds, and to place a felt nest in its place, and, when the young are hatched and old enough to be handled, to place a second clean nest, also of felt, in the box, removing the other. This is done to prevent acari. But I never knew that canaries so reared failed to make a nest when the breeding-time arrived. I have, on the other hand, marvelled to see how like a wild bird's the nests are constructed. It is customary to supply them with a small set of materials, such as moss and hair. They use the moss for the foundation, and line with the finer materials, just as a wild goldfinch would do, although, making it in a box, the hair alone would be sufficient for the purpose. I feel convinced nest-building is a true instinct." On the other hand, Mr. Charles Dixon, quoted[JS] in Mr. Wallace's "Darwinism," speaking of chaffinches which were taken to New Zealand and turned out there, says, "The cup of the nest is small, loosely put together, apparently lined with feathers, and the walls of the structure are prolonged for about eighteen inches, and hang loosely down the side of the supporting branch. The whole structure bears some resemblance to the nests of the hang-birds (Icteridæ), with the exception that the cavity is at the top. Clearly these New Zealand chaffinches were at a loss for a design when fabricating their nest. They had no standard to work by, no nests of their own kind to copy, no older birds to give them any instruction, and the result is the abnormal structure I have just described."

There is more evidence in favour of the view that the song of birds is, in part at least, imitative. That it has an innate basis is certain; and that it may be truly instinctive is shown by Mr. Couch's observation of a goldfinch which had never heard the song of its own species, but which sang the goldfinch-song, though tentatively and imperfectly. On the other hand, imitation is undoubtedly a factor. The Hon. Daines Barrington says (1773), "I have educated nestling linnets under the three best singing larks—the skylark, woodlark, and titlark—every one of which, instead of the linnet's song, adhered entirely to that of their respective instructors. When the note of the titlark linnet was thoroughly fixed, I hung the bird in a room with two common linnets for a quarter of a year. They were in full song, but the titlark linnet adhered steadfastly to that of the titlark." Mr. Wallace, who quotes this, adds,[JT] "For young birds to acquire a new song correctly, they must be taken out of hearing of their parents very soon, for in the first three or four days they have already acquired some knowledge of the parent's notes, which they afterwards imitate." Dureau de la Malle, as quoted by Mr. Romanes,[JU] describes how he taught a starling the "Marseillaise," and from this bird all the other starlings in a canton to which he took it are stated to have learned the air!

That dogs, monkeys, and other mammalia have powers of imitation needs no illustration. And when we remember that it is only the imitation of strange and unusual actions that arrests our attention, while the imitation of normal activities is likely to pass unnoticed, we may, I think, fairly surmise that imitation is by no means an unimportant factor in the acquisition and development of habits. And where the young animal is surrounded during the early plastic and imitative period of life by its own kith and kin, imitation will undoubtedly have a conservative tendency.

The education of young animals by their parents has also a conservative tendency. Mr. Spalding's observations show that the flight of birds is instinctive; but the parent birds normally aid the development of the instincts by instruction. Ants, as we have seen, are instructed in the business of ant-life. Dogs and cats train their young. And Darwin tells us, on the authority of Youatt,[JV] that lambs turned out without their mothers are very liable to eat poisonous herbs.

We may say, then, with regard to the influence of intelligence on instinctive activities, that it may lead them to vary along certain definite lines of increased adaptation; that it may, in some cases, lead them to vary along divergent lines, and hence tend to render stereotyped instincts more plastic; and that, through imitation and instruction, it may tend to render instinctive habits more uniform in a community, and hence, if the habits are tending to vary under changed circumstances in a given direction, may tend to draw the habits of all the members of the community in that given direction.

And with regard to the more general question of the variation of habits and instincts, we may say that, in addition to those variations in the origin and direction of which intelligence is a factor, there are other variations which take their origin without the influence of intelligence under the stress of changing circumstances, and yet others which may arise as we say "fortuitively" or "by chance," that is, from some cause or causes whereof we are at present ignorant, and which do not appear to be evoked directly by the stress of environing circumstances.

Granting, however, the existence of these variations in whatsoever way arising, and granting the influence of natural selection, of sexual selection, and perhaps of the inheritance of individually acquired modifications, those variations which are for the good of the race or species in which they occur will have a tendency to be perpetuated, while those which are detrimental will be weeded out and will tend to disappear.

Passing on now to consider the characteristics of those activities which we term "intelligent," we may first notice what Mr. Charles Mercier, in "The Nervous System and the Mind," calls the four criteria of intelligence. Intelligence is manifested, he says, first, in the novelty of the adjustments to external circumstances; secondly, in the complexity; thirdly, in the precision; and fourthly, in dealing with the circumstances in such a way as to extract from them the maximum of benefit.

Now, I think it is clear that, when it is our object to distinguish intelligent from instinctive activities, the precision of the adjustment cannot be regarded as a criterion of intelligence. Many instinctive acts are wonderfully precise. The sphex is said to stab the spider it desires to paralyze with unerring aim in the central nerve-ganglion. Other species, which paralyze crickets and caterpillars, pierce them in three and nine places respectively, according to the number of the ganglia. And yet this seems to be a purely instinctive action. So, too, to take but one more example, there is surely no lack of precision in the cell-making instinct of bees. We may say, then, that, granting that an action is intelligent, the precision of the adjustment is a criterion of the level of intelligence; but that, since there may be instinctive actions of wonderful precision, this criterion is not distinctive of intelligence. Nay, more, there are many reflex actions of marvellous precision and accuracy of adjustment; and there can be no question of intelligence, individual or ancestral, in many of these.

Nor can we regard prevision (which is sometimes advanced as a criterion of intelligence) as specially distinctive of intelligent acts regarded objectively in the study of the activities of animals. For, as we have already seen, there are many instincts which display an astonishing amount of what I ventured to term "blind prevision"—instance the instinctive regard for the welfare of unborn offspring, and the instinctive preparation for an unknown future state in the case of insect larvæ.

Nor, again, is the complexity of the adjustment distinctive of intelligence as opposed to instinct. The case of the sitaris, before given, the larva of which attaches itself to a male bee, passes on to the female, springs upon the eggs she lays, eats first the egg and then the store of honey,—this case, I say, affords us a series of sufficiently marked complexity. This instinct, the paralyzing, but not killing outright, of prey by the sphex; the marvellous economy of wax in the cell-building of the honey-bee; the affixing to their body, by crabs, of seaweed (Stenorhynchus), of ascidians (an Australian Dromia), of sponge (Dromia vulgaris), of the cloaklet anemone (Pagurus prideauxii); and other cases too numerous for citation;—these show, too, that the circumstances may be dealt with in such a way as to extract from them the maximum of benefit, probably without intelligence. It would be quite impossible intelligently to improve upon the manner of dealing with the circumstances displayed in many instinctive activities, even those which we have reason to believe were evolved without the co-operation of intelligence.

There remain, therefore, the novelty of the adjustment and the individuality displayed in these adjustments. And here we seem to have the essential features of intelligent activities. The ability to perform acts in special adaptation to special circumstances, the power of exercising individual choice between contradictory promptings, and the individuality or originality manifested in dealing with the complex conditions of an ever-changing environment,—these seem to be the distinctive features of intelligence. On the other hand, in instinctive actions there seems to be no choice; the organism is impelled to their performance through impulse, as by a stern necessity; they are so far from novel that they are performed by every individual of the species, and have been so performed by their ancestors for generations; and, in performing the instinctive action, the animal seems to have no more individuality or originality than a piece of adequately wound clockwork.

It may be said that, in granting to animals a power of individual choice, we are attributing to them free-will; and surely (it may be added), after denying to them reason, we cannot, in justice and in logic, credit them with this, man's choicest gift. I shall not here enter into the free-will controversy. I shall be content with defining what I mean by saying that animals have a power of individual choice. Two weather-cocks are placed on adjoining church pinnacles, two clouds are floating across the sky, two empty bottles are drifting down a stream. None of these has any power of individual choice. They are completely at the mercy of external circumstances. On the other hand, two dogs are trotting down the road, and come to a point of divergence; one goes to the right hand, the other to the left hand. Here each exercises a power of individual choice as to which way he shall go. Or, again, my brother and I are out for a walk, and our father's dog is with us. After a while we part, each to proceed on his own way. Pincher stands irresolute. For a while the impulse to follow me and the impulse to follow my brother are equal. Then the former impulse prevails, and he bounds to my side. He has exercised a power of individual choice. If any one likes to call this yielding to the stronger motive an exercise of free-will, I, for one, shall not say him nay. What I wish specially to notice about it is that we have here a sign of individuality. There is no such individuality in inorganic clouds or empty bottles. Choice is a symbol of individuality; and individuality is a sign of intelligence.

But though I decline here to enter into the free-will controversy, I may fairly be asked where I place volition in the series between external stimulus and resulting activity; and what I regard as the concomitant physiological manifestation. I doubt whether I shall be able to say anything very satisfactory in answer to these questions. I shall have to content myself with little more than stating how the problem presents itself to my mind.

I believe that volition is intimately bound up and associated with inhibition. I go so far as to say that, without inhibition, volition properly so called has no existence. When the series follows the inevitable sequence—

Stimulus: perception: emotion: fulfilment in action

—the act is involuntary. And such it must ever have remained, had not inhibition been evolved, had not an alternative been introduced, thus—

At the point of divergence I would place volition. Volition is the faculty of the forked way. There are two possibilities—fulfilment in action or inhibition. I can write or I can cease writing; I can strike or I can forbear. And my poor little wounded terrier, whose gashed side I was sewing up, clumsily, perhaps, but with all the gentleness and tenderness I could command, could close his teeth on my hand or could restrain the action.

I have here, so to speak, reduced the matter to its simplest expression. It is really more complex. For volition involves an antagonism of motives, one or more prompting to action, one or more prompting to restraint. The organism yields to the strongest prompting, acts or refrains from acting according as one motive or set of motives or the other motive or set of motives prevails; in other words, according as the stimuli to action or the inhibitory stimuli are the more powerful.

And then we must remember that the perceptual volition of animals becomes in us the conceptual volition of man. An animal can choose, and is probably conscious of choosing. This is its perceptual volition. Man not only chooses, and is conscious of choosing, but can reflect upon his choice; can see that, under different circumstances, his choice would have been different; can even fancy that, under the same circumstances (external and internal), his choice might have been different. This is conceptual volition. Just as Spinoza said that desire is appetence with consciousness of self; so may we say that the volition of contemplative man is the volition of the brute with consciousness of self. No animal has consciousness of self; that is to say, no animal can reflect on its own conscious states, and submit them to analysis with the formation of isolates. Self-consciousness involves a conception of self, persistent amid change, and isolable in thought from its states. It involves the isolation in thought of phenomena not isolable in experience. We can think about the self as distinct from its conscious states and the bodily organization; but they are no more separable in experience than the rose is separable from its colour or its scent. Such isolation is impossible to the brute. An animal is conscious of itself as suffering, but the consciousness is perceptual. There is no separation of the self as an entity distinct from the suffering which is a mere accident thereof; no conception of a self which may suffer or not suffer, may act or may not act, may be connected with the body or may sever that connection. Just as there is a vast difference between the perception of an object as here and not there, of an occurrence as now and not then, of a touch as due to a solid body; and the conception of space, time, and causation; so is there a vast difference between a perception of an injury as happening to one's self, and a conception of self as the actual or possible subject of painful consciousness. This difference is clearly seen by Mr. Mivart, who therefore speaks of the consentience of brutes as opposed to the consciousness of man. Consciousness he regards as conceptual; consentience as perceptual.[JW] And, as before stated, I should be disposed to accept his nomenclature, were it not for its philosophical implications. For Mr. Mivart regards the difference between consciousness and consentience as a difference in kind, whereas I regard it as a generic difference. I believe that consentience (perceptual consciousness) can pass and has passed into consciousness (conceptual consciousness); but Mr. Mivart believes that between the two there is a great gulf fixed, which no evolutionary process could possibly bridge or span.

The perceptual volition of animals, then, is a state of consciousness arising when, as the outcome of perception and emotion, motor-stimuli prompting to activity conflict with inhibitory stimuli restraining from activity. The animal chooses or yields to the stronger motive, and is conscious of choosing. But it cannot reflect upon its choice, and bother its head about free-will. This involves conceptual thought. When physiologists have solved the problem of inhibition, they will be in a position to consider that of volition. At present we cannot be said to know much about it from the physiological standpoint.

Still, as before indicated, the fact of inhibition is unquestionable and of the utmost importance. It has before been pointed out that through inhibition, through the suppression or postponement of action, there has been rendered possible that reverberation among the nervous processes in the brain which is the physiological concomitant of æsthetic and conceptual thought. We have just seen that, in association with inhibition, the faculty of volition has been developed. And we may now notice that the postponement or suppression of action is one of the criteria of intelligent as opposed to instinctive or impulsive activities. This is, however, subordinate to the criterion of novelty and individuality.

Granting, then, that an action is shown to be intelligent from the novelty of the adjustments involved, and from the individuality displayed in dealing with complex circumstances (instinctive adjustments being long-established and lacking in originality), we may say that the level of intelligence is indicated by the complexity of the adjustments; their precision; the rapidity with which they are made; the amount of prevision they display; and in their being such as to extract from the surrounding conditions the maximum of benefit.

Before closing this chapter, I will give a classification of involuntary and voluntary activities:—

In the involuntary acts classed as automatic and reflex, the initiation and the result may be accompanied by consciousness, but the intermediate mental link which answers to the motive in higher activities is, I think, unconscious. In habitual and instinctive activities the consciousness of the percept and the impulse may in some cases have become evanescent, or, to use G. H. Lewes's phrase, have lapsed. In the case of some instincts, originating by the natural selection of unintelligent activities, the perceptual element may never have emerged, and the initiation may have been a mere sense-stimulus.

The division of voluntary activities into perceptual and conceptual follows on the principles adopted and developed in this work. As to the terminology employed, I agree with Mr. S. Alexander[JX] that it is convenient to reserve the terms "desire" and "conduct" for use in the higher conceptual plane. Animals, I believe, are incapable of this higher desire and this higher conduct. It only remains to note that it is within the limits of the fourth class (of voluntary activities initiated by concepts) that morality takes its origin. Morality is a matter of ideals. Moral progress takes its origin in a state of dissatisfaction with one's present moral condition, and of desire to reach a higher standard. The man quite satisfied with himself has not within him this mainspring of progress. The chief determinant of the moral character of any individual is the ideal self he keeps steadily in view as the object of moral desire—the standard to be striven for, but never actually attained.