p>The Atlantic Monthly, Volume 05, No. 31, May, 1860 / A Magazine of Literature, Art, and Politics
INSTINCT
"Instinct is a great matter," quoth Falstaff, when called upon to find out a device, a "starting-hole," to hide himself from the open and apparent shame of having run away from the fight and hacked his sword like a handsaw with his own dagger. Like a valiant lion, he would not turn upon the true prince, but ran away upon instinct. Although the peculiar circumstances of the occasion upon which the subject was presented to Falstaff's mind were not very favorable to a calm consideration of it, he was undoubtedly correct in saying that instinct is a great matter. "If, then, the tree may be known by the fruit," says Falstaff, "as the fruit by the tree, then, peremptorily I speak it, there is virtue in that Falstaff"; and it is proper that his authority should be quoted, even upon a question of metaphysical science.
That psychological endowment of animals which we denominate instinct has in every age been a matter full of wonder; and men of thought have found few more interesting subjects of inquiry. But it is confessed that little has been satisfactorily made out concerning the nature and limitations of instinct. In former times the habits and mental characteristics of those orders of animated being which are inferior to man were observed with but a careless eye; and it was late before the phenomena of animal life received a careful and reverent examination. It is vain to inquire what instinct is, before there has been an accurate observation of its manifestations. It is only from its outward manifestations that we can know anything of that marvellous inward nature which is given to animals. We cannot know anything of the essential constitution of mind, but can know only its properties. This is all we know even of matter. "If material existence," says Sir William Hamilton, "could exhibit ten thousand phenomena, and if we possessed ten thousand senses to apprehend these ten thousand phenomena of material existence, of existence absolutely and in itself we should be then as ignorant as we are at present." But this limitation of human knowledge has not always been kept in view. Men have been solicitous to penetrate into the higher mysteries of absolute and essential existence. But in thus reaching out after the unattainable, we have often passed by the only knowledge which it was possible for us to gain. Much vague speculation concerning instinct has arisen from the attempt to resolve the problem of its ultimate nature; and perhaps much more might have been made out with certainty about it, if no greater task had been attempted than to classify the phenomena which it exhibits and determine the nature of its manifestations. In regard to instinct, as well as everything else, we must be content with finding out what it seems to us to be, rather than what it is. Even with this limitation, the inquiry will prove sufficiently difficult. The properties of instinct are a little more inscrutable than those of the human mind, inasmuch as we have our own consciousness to assist us in this case, while we are left to infer the peculiarities of instinct from its outward manifestations only. And moreover, the inquiry involves an understanding of the workings of the human mind; for it is only when viewed in contrast with the rational endowments of man that the character of instinct is best known. All other questions connected with the subject are subordinate to this one of the apparent difference between instinct and reason.
Many definitions have been given of instinctive actions. These differ widely in their extent, and are for the most part quite inadequate. Some writers have ranged under this term all those customary habits and actions which are common to all the individuals of a species. According to this definition, almost every action of animated life is instinctive. But the general idea of an instinctive action is much more restricted; it is one that is performed without instruction and prior to experience,—and not for the immediate gratification of the agent, but only as the means for the attainment of some ulterior end. To apply the term instinct to the regular and involuntary movements of the bodily organs, such as the beating of the heart and the action of the organs of respiration, is manifestly an extension of the ordinary acceptation of the term. Organic actions of a similar character are also performed by plants, and are purely mechanical. "In the lowest and simplest class of excited movements," says Müller, "the nervous system would not appear to be concerned. They result from stimuli directly applied to the muscles, which immediately excite their contractility; and they are evidently of the same character with the motions of plants." Thus, the heart is excited to pulsation by the direct contact of the blood with the muscle. The hand of a sleeping child closes upon any object which gently touches the palm. And it is in this way, doubtless, that the Sea Anemone entraps its prey, or anything else that may come in contact with its tentacles. But so far are these movements from indicating of themselves the action of any instinctive principle, that they are no proof of animality; for a precisely analogous power is possessed by the sensitive plant known as the Fly-Trap of Venus (Dionoea muscipula): "any insect touching the sensitive hairs on the surface of its leaf instantly causes the leaf to shut up and enclose the insect, as in a trap; nor is this all; a mucilaginous secretion acts like a gastric juice on the captive, digests it, and renders it assimilable by the plant, which thus feeds on the victim, as the Actinea feeds on the Annelid or Crustacean it may entrap." In the animal organization a large class of reflex actions are excited, not by a direct influence, but indirectly by the agency of the nerves and spinal cord. Such actions are essentially independent of the brain; for they occur in animals which have no brain, and in those whose brain has been removed. However marvellous these functions of organic life may be, there is nothing in them at all resembling that agency properly called instinct, which may be said to take the place in the inferior tribes of reason in man. To refer these operations to the same source as the wonderful instinct that guides the bird in its long migratory flight, or in the construction of its nest, would be to make the bird a curiously constructed machine which is operated by impressions from without upon its sentient nerves.
Those actions have sometimes been called instinctive which arise from the appetites and passions; and they have been referred to instinct, doubtless, because they have one characteristic of instinct,—that they are not acquired by experience or instruction. "But they differ," says Professor Bowen, "at least in one important respect from those instincts of the lower animals which are usually contrasted with human reason. The objects towards which they are directed are prized for their own sake; they are sought as ends; while instinct teaches brutes to do many things which are needed only as means for the attainment of some ulterior purpose." When the butterfly extracts the nectar from the flowers which she loves most, she meets a want of her physical nature which demands satisfaction at the moment; but when, in opposition to her appetite, she proceeds to the flowerless shrub to deposit her eggs upon the leaves best suited to support her unthought-of progeny, she is not influenced by any desire for the immediate gratification of her senses, but is led to the act by some dim impulse, in order that an ultimate object may be provided for to which she has no reference at the time. We are surprised to find it declared, in the very interesting "Psychological Inquiries" of Sir B.C. Brodie, that the desire for food is the simplest form of an instinct, and that such an instinct goes far towards explaining others which are more complicated. It is true that the appetites and passions of animals have an ultimate object, but they are impelled to action by a desire for immediate gratification only; but when we speak of an instinct, we mean something more than a mere want or desire,—we have chiefly in view the end beyond the blind instrumentality by which it is reached.
When we watch the movements of a young bee, as it first goes forth from its waxen cradle, we are forced to recognize an influence at work which is unlike reason, and which is neither appetite nor any mechanical principle of organic life. Rising upon the comb, and holding steadily with its tiny feet, with admirable adroitness the young bee smooths its wings for its first flight, and rubs its body with its fore legs and antennae; then walking along the comb to the mouth of the hive, it mounts into the air, flies forth into the fields, alights upon the proper flowers, extracts their juices, collects their pollen, and, kneading it into little balls, deposits them in the sacks upon its feet; and then returning to its hive, it delivers up the honey and the wax and the bread which it has gathered and elaborated. In the hive it works the wax with its paws and feelers into an hexagonal cell with a rhomboidal bottom, the three plates of which form such angles with each other as require the least wax and space in the construction of the cell. All these complex operations the bee performs as adroitly, on the first morning of its life, as the most experienced workman in the hive. The tyro gatherer sought the flowery fields upon untried wings, and returned to its home from this first expedition with unerring flight by the