§ 5. The True Significance of Instinct
A third class of facts commonly cited as evidence of bestial intelligence are the remarkable phenomena of instinct.[14] The beaver acts as though it were acquainted with the principles of hydraulics and engineering, when it maintains the water at the height requisite to submerge the entrance to its dwelling by building a dam of mud, logs, and sticks across the stream at a point below the site of its habitation. The predatory wasp Pompilius is endowed with surgical art, that suggests a knowledge of anatomy, inasmuch as it first disarms and afterwards paralyzes its formidable prey, the Lycosa or black Tarantula. Another predatory wasp, the Stizus ruficornis, disables Mantids in a similar fashion. One of the American Pompilids, the black wasp Priocnemis flavicornis, is an adept in the art of navigation, since it adopts the principle of the French hydroglissia (an air-driven boat which skims the water under the propulsion of an aeroplane propeller). This insect tows a huge black spider several times its own size and too heavy to be carried, propelling its prey with buzzing wings along the open waterway, and leaving behind a miniature wake like that of a steamer. It thus avoids the obstacles of the dense vegetation, and saves time and energy in transporting the huge carcass of its paralyzed quarry to the haven of its distant burrow. Spiders like the Epeira, for example, are endowed with the mathematical ability of constructing their webs on the patterns of the logarithmic spiral of Jacques Bernouilli (1654-1705), a curve which it took man centuries to discover. The dog infested with parasitic tapeworms (Taenia) evinces a seeming knowledge of pharmaceutics, seeing that it will avidly devour Common Wormwood (Artemisia absynthium), an herb which it never touches otherwise.
In all these cases, however, as we have previously remarked, the illusion of intelligence is due to the combination of teleology or objective purposiveness with sentient consciousness. But teleology is nothing more than a material expression of intelligence, not to be confounded with subjective intelligence, which is its causal principle. When the cells of the iris of the eye of a larval salamander regenerate the lens in its typical perfection, after the latter has been experimentally destroyed, we behold a process that is objectively, but not subjectively, intelligent. In like manner the instinctive acts of an animal are teleological or objectively purposive, but do not proceed from an intelligence inherent in the animal, any more than the intelligent soliloquy delivered by a phonograph proceeds from a conscious intelligence inherent in the disc. In the animal, sentient consciousness is associated with this teleology or objective purposiveness, but such consciousness is only aware of what can be sensed, and is, therefore, unconscious of purpose, that is, of the supersensible link, which connects a means with an end. “Instinct,” to cite the words of Wm. James, “is usually defined as the faculty of acting in such a way as to produce certain ends, without foresight of the ends, and without previous education in the performance.” (“Principles of Psychology,” vol. II, c. xxiv, p. 383.) Hence the unconscious and objective purposiveness, which the human mind discerns in the instinctive behavior of brutes, is manifestative, not of an intelligence within the animal itself, but only of the infinite intelligence of the First Cause or Creator, Who imposed these laws replete with wisdom upon the animal kingdom, and of the finite intelligence of man, who is capable of recognizing the Divine purpose expressed, not only in the instincts of animals, but in all the telic phenomena of nature. Such marvels are not the fortuitous result of uncoördinated contingencies. Behind these correlated teleologies of the visible universe there is a Supreme Intelligence, which has “ordered all things in measure, and number, and weight.” (Wisdom: XI, 21.) “And this universal geometry,” says Fabre, in allusion to the mathematics of the Epeira’s web, “tells of an Universal Geometrician, whose divine compass has measured all things. I prefer that, as an explanation of the logarithmic curve of the Ammonite and the Epeira, to the Worm screwing up the tip of its tail. It may not perhaps be in accordance with latter-day teaching, but it takes a loftier flight.” (“Life of the Spider,” p. 400.)
But, though the teleology of instinct is wonderful in the extreme, the element of psychic regulation is so subordinate and restricted, that, far from postulating intelligent control, certain scientists go so far as to deny even sentient control, in the case of instinctive behavior. Animals, in their opinion, are nothing more than “reflex machines,” a view which coincides with that of Descartes, who regarded animals as unconscious automatons. “The instincts,” says Pawlow, “are also reflexes but more complex.” (Science, Nov. 9, 1923, p. 359.) The late Jacques Loeb was a protagonist of the view that instincts are simply metachronic chain-reflexes, in which one elementary process releases another, each preceding phase terminating in the production of the succeeding phase, until the entire gamut of concatenated arcs has been traversed. Hence, John B. Watson, the Behaviorist disciple of Loeb, defines instinct as “a combination of congenital responses unfolding serially under appropriate stimulation.”
But, if Darwinian anthropomorphism sins by excess, Loeb’s mechanism sins by defect, and fails to account for the indubitable variability of instinctive behavior. For, however fixed and stereotyped such behavior may be, it manifests unmistakable adaptation to external circumstances and emergencies, as well as subordination to the general physiological condition of the organism, phenomena that exclude the idea of fatal predetermination according to the fixed pattern of a determinate series of reflex arcs. As Jennings has shown, synaptic coördination in the neural mechanism cannot be more than a partial factor in determining serial responses. The state of the organism as a whole must also be taken into account. (Cf. “Behavior of the Lower Organisms,” p. 251.) Thus an earthworm may turn to the right simply because it has just turned to the left, but this so-called “chain-reflex” does not involve an invariable and inevitable sequence of events, since the earthworm may turn twice or thrice to the left, before the second reaction of turning to the right comes into play. Any animal, when sated, will react differently to a food stimulus than it will when it is starved, by reason of its altered organic condition. We have something more, therefore, to reckon with than a mere system of reflexes released by a simple physical stimulus.
The second type of variability manifested by instinct is its capacity for complex and continuous adjustment to variable environmental circumstances. Thus predatory animals, such as wasps, crabs, spiders, and carnivorous mammals, accommodate themselves appropriately and uninterruptedly to the changing and unforeseeable movements of the prey they are engaged in stalking, giving evidence in this way of the regulation of their hunting instincts by sensory impressions. Whether this element of psychic control is based upon object-perception, or simple sensation, and whether it involves a sensual impulse, or is merely sensori-motor, we have, naturally, no direct means of ascertaining. But the presence of some sort of sensory regulation is evident enough, e.g. in the prompt and unerring flight of vultures to distant carrion. Moreover, there is a close analogy between our sense organs and those of an animal. Particularly, in the case of the higher animals, the resemblance of the sense organs and nervous system to our own is extremely close, so much so that even the localization of sensory and motor centers in the brain is practically identical in dogs, apes, and men. Moreover, the animals make analogous use of their sense organs, orientating them and accommodating them for perception, and using them to inspect strange objects, etc., e.g. they turn their eyes, prick up their ears, snuff the wind, etc. Again, analogous motor and emotional effects result from the stimulation of their sense organs, and brutes make emotional displays of anger, exultation, fear, etc., similar to our own. Hence it is to be presumed that they have similar sensuous experiences. The analogy, however, must not be pressed further than the external manifestations warrant. With brute animals, the manifestations in question are confined exclusively to phenomena of the sensuous order.
Another indication of sensory control is found in the repair-work performed by animals endowed with the constructive instinct. C. F. Schroeder, for instance, experimenting on certain caterpillars, found that they repaired their weaving, whenever it was disturbed by the experimenter. Fabre, too, discovered that a Mason-bee would plaster up holes or clefts marring the integrity of its cell, provided that the bee was actually engaged in the process of plastering at the time, and provided that the experimenter inflicted the damage at the level, and within the area, of the construction work on which the bee was then engaged. In a word, if the damage inflicted could be repaired by a simple continuation or extension of its actual work of the moment, the bee was able to cope with the emergency. There are other ways, too, in which the animal adapts its constructive instincts to external circumstance. Fabre tells us that the Bramble-bee Osmia, which builds a train of partitioned cells in snail shells or in hollow reeds, will victual first and then plaster in a partition, if the reed be narrow, but will first plaster a partition, and then introduce honey and pollen through a hole left unclosed in the partition, whenever the reed is of greater diameter. This reversal of the procedure according to the exigencies of the external situation does not suggest the chain-reflex of Loeb. (Cf. “The Bramble-Bee,” pp. 214-217.) Another kind of adaptation of instinct to external circumstances consists in the economical omission of the initial step of a serial construction, in cases where the environmental conditions provide a ready-made equivalent. “The silkworm,” says Driesch, “is said not to form its web of silk if it is cultivated in a box containing tulle, and some species of bees which normally construct tunnels do not do so if they find one ready made in the ground, they then only perform their second instinctive act: separating the tunnel into single cells.” (“Science & Phil. of the Organism,” vol. II, p. 47.)
Driesch’s analysis of the constructive instinct shows that these facts of adaptation or regulation fit in with the idea of sensory control rather than with that of a chain-reflex. In the supposition that the successive stages of instinctive construction are due to a chain-reflex, consisting of a series of elementary motor reactions a, b, c, etc., in which a produces the external work A and, on terminating, releases b, which, in turn, produces external work B and releases c, etc., clearly b could never appear before a, and the sight of A ready-made would not inhibit a, nor would the removal of A defer the advent of b. In other words, regulation would be impossible. But, if we suppose that not the elemental act a, but rather the sensory perception of A, the first state of the external construction, is the stimulus to b and, consequently, to the production of the second state of construction B, then we understand why b is released independently of a, when, for example, an insect discovers a ready-made substitute for A, the initial step in its construction, and we also understand why, in cases of accidental damage resulting in the total or partial removal of A, the reaction b is deferred and the reaction a prolonged, until the repair or reconstruction of A is complete; for, in this supposition, the addition of A will inhibit a and release b, whereas the subtraction of A will inhibit the appearance of b and consequently defer B, until the state of construction A, the sight of which is the stimulus to b, is complete. The fact of regulation, therefore, entails sensory control of the serial responses involved in the constructive instinct. Hence, as H. P. Weld of Cornell expresses it: “We may safely assume that even in the lowest forms of animal life some sort of sensory experience releases the (instinctive) disposition and to an extent determines the subsequent course of action.” (Encycl. Am., v. 15, p. 168.)
But it would be going to the opposite extreme to interpret these adjustments of instinct to external contingencies as evidence of intelligent regulation. The animal’s ability, for example, to repair accidental damage to a construction, which instinct impels it to build, is rigidly limited to repairs that can be accomplished by a simple continuation of the actual and normal occupation of the moment. If, however, the damage affects an already completed portion of the instinctive structure, and its present occupation is capable of continuance, the animal is impotent to relinquish this actual occupation of the moment, in order to cope with the emergency. Suppose, for illustration, that the instinctive operations a and b are finished and the animal is in the c-stage of its instinctive performance, then, if the damage is inflicted in the A-portion of the structure, and c can be continued independently of A, the animal cannot relinquish c and return to a, in order to restore the marred integrity of A. This shows that the animal is guided, in its repair-work, by sense, which is bound to the here and now, and not by intelligence, which is an abstractive faculty that emancipates from the actual and concrete present, and enables the possessor to hark back to the past of its performance, should necessity require. Thus Fabre found that the Mason-bee, after it had turned from building to the foraging of honey and pollen, would no longer repair holes pricked in its cell, but suffered the latter to become a veritable vessel of the Danaïdes, which it vainly strove to fill with its liquid provender. Though the holes affected portions extremely close to the topmost layer of masonry, and although it frequently sounded and explored these unaccustomed holes with its antennæ, it took no steps to check the escape of the honey and pollen by recurring to its mason craft of earlier stages. And, finally, when it did resume the plasterer’s trade in constructing a lid for the cell, it would spare no mortar to plug the gaping breaches in the walls of its cell, but deposited its egg in a chamber drained of honey, and then proceeded to perform the useless work of closing with futile diligence only the topmost aperture in this much perforated dwelling. Obviously, therefore, the bee failed to perceive the connection which existed between these breaches and the escape of the honey, and it was unable to apply its instinctive building skill to new uses by abstraction from the definite connection, in which the latter is normally operative.
Sense, therefore, and not intelligence, is the regulatory principle of instinct. To recognize causal and telic relationships is the prerogative of a superorganic intelligence. The transcendental link by which a useful means is referred to an ulterior end is something that cannot be sensed, but only understood. An animal, therefore, acts toward an end, not on account of an end. Nature, however, has compensated for this ignorance by implanting in each species of animal a special teleological disposition, by reason of which objects and actions, which are, under normal conditions, objectively useful to the individual, or the species, become invested for the animal with a subjective aspect of agreeableness, while objects and actions, which are normally harmful, are invested with a subjective aspect of repulsiveness. The qualities of serviceableness and pleasantness happen, so far as the animal is concerned, to be united in one and the same concrete object or action, but the animal is only aware of the pleasantness, which appeals to its senses, and not of the serviceableness, which does not. Thus, in the example already cited, the dog suffering from tapeworms eats the herb known as Common Wormwood, not because it is aware of the remedial efficacy of the herb, but simply because the odor and flavor of the plant appeal to the animal in its actual morbid condition, ceasing to do so, however, when the latter regains the state of health. How different is the action of the man whose blood is infected with malarial parasites and who takes quinine, not because the bitter taste of the alkaloid appeals to his palate, but solely because he has his future cure explicitly in view! “Finally,” says Weld, “the more we learn about instincts the more apparent it becomes that the situations from which they proceed are meaningful, but we need not suppose that the organism is aware of the meaning. The chick in the egg feels (we may only guess as to its nature) a vague discomfort, and the complicated reaction by which it makes its egress from the shell is released.” (Encycl. Am., v. 15, p. 169.)