In vain, then, do our Darwinian humanizers of the brute exalt instinct at the expense of intelligence. Their attempt to reduce to a difference of degree the difference of kind that separates the irrational from the rational, fails all along the line. Indeed, far from being able to account for the appearance of intelligence in the world, transformistic theories are impotent to account for so much as the development of instinct, all forms of the evolutionary theory, the Lamarckian, the Darwinian, the De-Vriesian, etc., being equally inadequate to the task of explaining the origin of animal instincts.
The complex instinctive behavior of predatory wasps, for example, is absolutely essential for the preservation of their respective races, and yet these indispensable instincts are completely useless in any other than the perfect state. From their very nature, therefore, they do not admit of gradual development. The law of all, or none, holds here. “Instinct developed by degrees,” says Fabre, “is flagrantly impossible. The art of preparing the larva’s provisions allows none but masters, and suffers no apprentices; the Wasp must excel in it from the outset or leave the thing alone.” (“The Hunting Wasps,” p. 403.) To be useful at all, the instinctive operation must possess an indivisible perfection, which cannot be partitioned into degrees. The Pompilius (Calicurgus), for instance, must, under penalty of instant death, take the preliminary precaution to sting into inaction the ganglion that controls the poison forceps of her formidable prey, the Black Tarantula (Lycosa), before she proceeds to paralyze it by stabbing its thoracic ganglion. The slightest imperfection or shortcoming in her surgery would be irretrievably disastrous. Such an instinct never existed in an imperfect form. The first wasp to possess it must have been an expert, or she would never have lived to serve the limp body of the huge spider as living provender for her tiny grub. “The first to come to grips with the Tarantula,” says Fabre, “had an unerring knowledge of her dangerous surgery. The least hesitation, the slightest speculation, and she was lost. The first teacher would also have been the last, with no disciples to take up her art and perfect it.” (“Bramble Bees,” p. 354.)
Another hunting wasp, the Hairy Ammophila, subdues a large caterpillar into a state of coma by pricking with its sting nine of the ventral ganglia, while it spares the cervical ganglion, merely compressing the latter with its mandibles, so as not to destroy life altogether. This nice discrimination rules out Loeb’s hypothesis of a so-called “chemotaxis.” As a result of this elaborate surgical operation, the power of movement is suppressed in every segment, and the tiny larva of the wasp emerging from the egg laid on the ventral surface of the caterpillar can devour this huge living, but motionless, victim in peace and safety. Dead meat would not agree with the larva, and any movement of the caterpillar would be fatal to the delicate grub. To eliminate these contingencies, the Wasp’s surgery must be perfect from the very outset. “There is,” says Fabre, “no via media, no half success. Either the caterpillar is treated according to rule and the Wasp and its family is perpetuated; or else the victim is only partially paralyzed and the Wasp’s offspring dies in the egg. Yielding to the inexorable logic of things, we will have to admit that the first Hairy Ammophila, after capturing a Grey Worm to feed her larva, operated on the patient by the exact method in use today.” (“The Hunting Wasps,” pp. 403, 404.)
Certain meticulous critics of our day cite the fact of the diffusion of the poison as indicating that the surgery of the hunting wasps need not be so perfectly accommodated to the nervous system of their prey, and they attempt in this way to discredit Fabre as having failed to take the occurrence of diffusion into account. A careful reading of his works, however, will serve to vindicate him in this respect. In a chapter on the poison of the bee, for instance, we read: “The local effect is diffused. This diffusion, which might well take place in the victims of the predatory insects, plays no part in the latter’s method of operation. The egg, which will be laid immediately afterwards, demands the complete inertia of the prey from the outset. Hence all the nerve-centers that govern locomotion must be numbed instantaneously by the virus.” (“Bramble Bees,” p. 347.) Bouvier, therefore, very justly remarks: “After all, when Fabre’s work is examined there is no trouble in seeing that none of these details escaped him. He never disputed the paralytic action of the poison inoculated by the insect, and the wonderful researches by the Peckhams on the Pompilids, which hunt Lycosids, have clearly established the fact that the thrusts of the sting given by the predatory insect produce two different kinds of paralysis, one functional, and often temporary, resulting from the action of the venom, the other structural and persistent, produced by the dart which more or less injures the nervous centers.” (Smithson. Inst. Rpt. for 1916, p. 594.)
In the case of predatory insects, therefore, the instinct must be perfect at the outset, or survival is impossible. For the origin of such instincts, Darwinism, which stresses the gradualness of evolutionary progress, has no explanation that will hold water. Lamarckism, which sees in acquired habits transmitted by inheritance, the origin of instinct, the “memory of the race,” is equally at a loss to account for these instincts. The formation of habits requires practice and repetition. The predatory insect must be perfect at the start, and yet it only exercises its remarkable instinct once a year. Where is the practice and reiteration requisite for canalizing its nervous system into the conduction-paths of habit? How did one particular set of rarely performed acts happen to gain precedence over all others, and to be alone successful in stamping themselves indelibly upon the nerve plasm as habits, and upon the germ plasm as instincts? De-Vriesianism, which would make the acquisition and perfecting of instinct dependent upon the rare and accidental contingency of a fortuitous mutation, is even more objectionable. These instincts are vital to the insect. If their acquisition and improvement depend upon the lucky chance of a series of favorable mutations, its prospects of survival are nil; for it cannot afford to wait at all. “In order to live,” says Fabre, “we all require the conditions that enable us to live: this is a truth worthy of the famous axioms of La Palice. The predatory insects live by their talent. If they do not possess it to perfection, their race is lost.” (“Bramble Bees,” p. 364.)
Recently, there has been a revival of Lamarckism hitherto regarded as defunct. Guyer, Kammerer, and Pawlow profess to find factual justification for it, and Bouvier adopts it in his “La vie psychique des insectes” (1918), to account for the origin of instinct. Of the alleged facts of Kammerer and Guyer, we have spoken in a previous chapter. Here we shall content ourselves with few remarks on the experiments of Ivan Pawlow, as being especially relevant to the subject under consideration. The Russian physiologist has experimented on white mice, and claims that the mice of the fifth generation learned to answer a dinner bell in the space of five lessons, whereas their ancestors of the first generation had required a hundred lessons to answer the same signal. Hence he concludes: “The latest experiments ... show that conditioned reflexes, i.e., the highest nervous activity, are inherited.” (Science, Nov. 9, 1923, p. 360.) His results, however, do not tally with those recently obtained by E. C. MacDowell of the Carnegie Institution, by H. G. Bragg, and by E. M. Vicari of Columbia. MacDowell found that white rats trained in a circular maze did not improve in their susceptibility to training from generation to generation. “Children from trained parents,” he says, “or from trained parents and grandparents, take as long to learn the maze habit as the first generation used.” (Science, March 28, 1924, p. 303.) Having cited the similar results of Bragg, who experimented with white mice, he concludes: “The results are in full accord with those given above; they indicate that the training of the ancestors did not facilitate the learning of the descendants.” (Ibidem.) E. M. Vicari, using a simple maze and white rats, obtained the same results. “It seems clear,” she says, “that the latter generations have not been aided by the training of their ancestors.” (Ibidem.)
Bouvier’s conception, then, that the automatisms of instinct originate as automatisms of acquired habit, the latter being appropriated by inheritance, still stands in need of reliable experimental confirmation. Moreover, a theory of this sort could never account, as Weismann points out, for such phenomena as the specific instincts of worker bees, which are excluded from propagation. Nor can the theory explain, as originating in acquired habit, those instinctive operations of enormous complexity, like the complicated method of emergence employed by the larva of the emperor moth, which only occur once in a lifetime, and could not, therefore, fasten themselves on the organism as a habit.
An evolutionary origin of instinct, however, though extremely improbable, is, at any rate, not absolutely inconceivable. Its teleology, as we have seen, does not imply inherent intelligence, but is explicable as an innate law involving appropriate coördination of the sensory, emotional, and motor functions, all of which are intrinsically dependent on the organism. But intelligence, as we have seen, is a superorganic power, having its source in a spiritual principle, that, from the very nature of things, cannot be evolved from matter. Human reason, therefore, owes its origin, not to any evolution of the human body, but to the creation of the human soul, which is the source and subject of that unique prerogative of man, namely: the power of abstract thought.
CHAPTER III
THE ORIGIN OF THE HUMAN BODY
In an article published August 31, 1895, in the New York Freeman’s Journal, the late Rev. J. A. Zahm gave expression to the following opinion: “The evolution of the body of man from some inferior animal and its subsequent endowment in this body by God of a rational soul is antagonistic to no dogma of faith and may be shown to be in harmony with the teachings of St. Thomas.” The scriptural and theological aspect of this view need not concern us here, our sole purpose being to evaluate it from a purely scientific standpoint. Once evolutionary thought takes cognizance of the fact that the human soul is a spiritual principle underivable from mere matter, once it acknowledges the immediate creation of the human soul, and professes to do no more than account for the origin of man’s animal body, that moment is it shorn of its materialistic implications; but what, we may ask, are the foundations of such an hypothesis in the realm of scientific fact?