Three in European folklore, Five in Oregon and northern Nevada, Six among the Ainu of Yezo, Nine among the Yakut, Ten among the Pythagorean philosophers of ancient Greece, very much as Four does among the Crow. Now the fact that a particular Crow Indian regards Four as a sacred number does not mean that this is an individual peculiarity of his any more than the Christian’s reaction to a cross is a proof of some psychological idiosyncrasy. Individually the Crow Indian may be quite indifferent to the number and yet he would view it as sacred because he has been taught so to regard it. This is, of course, the vital difference between ethnology and psychology which has already been emphasized. Nevertheless, the association must at one time have been formed in an individual mind, whether among the Crow or elsewhere, and the question arises as to what such an association means. Francis Galton showed some time ago that such associations of definite personal characteristics with numbers occur by no means infrequently among Europeans. The phenomenon we are dealing with is thus linked with a group of related phenomena and in so far forth is explained.

There are ethnologists who would not admit that such an explanation has anything to do with ethnology. They would contend that as soon as we cease to investigate the group as such we are passing from ethnology, the science of culture, to psychology, the science of individual minds. This seems an unnecessarily narrow doctrinaire view. Knowledge, as stated above, is not subdivided by hard-and-fast partitions. Interest certainly does not stop at an arbitrary point in the investigation but is centered on a comprehension of the whole phenomenon. Where that phenomenon is an alloy of tin and copper, a decision as to its nature is naturally left to chemistry; it seems not unreasonable that where it is a type of association we should turn for enlightenment to psychology.

Another field supplies an additional illustration. One of the important subjects for ethnographic study is artistic form. The ethnologist notes in a purely descriptive way the decorative patterns employed by various tribes, the fact that curvilinear motives are prominent among the Maori of New Zealand while the rawhide bags of Plains Indians are covered with angular paintings. Here, once more, it is clear that many of the problems that arise are purely cultural. There are, nevertheless, psychological elements involved that may be misunderstood without psychological knowledge. Let us assume, e.g., that a certain tribe is artistically characterized by a fondness for squares. What does this predilection signify? It is a psychological commonplace that through an optical illusion we exaggerate the height as compared with the width of a rectangle; accordingly, the geometrical square does not coincide with the psychological square. This simple piece of information enables us to understand what we are actually dealing with in the case of a square pattern. At the same time it sharpens our observation regarding such patterns. It is quite conceivable that in one place tribal taste should prefer the actual square while elsewhere the psychological square occupies the seat of honor. This would be a purely ethnographic fact, yet its discovery might be considerably expedited by some knowledge of experimental aesthetics.

Let us turn from mystic numbers and decorative designs to another aspect of primitive life. The Turkish tribes of western Siberia have a form of religion based on the belief that certain individuals enjoy the hereditary privilege of acting as intermediaries between their ancestral spirits and the people at large. With the aid of his sacred drum the shaman, as such an intermediary is technically called, is able to summon the supernatural beings, cure the sick, foretell the future, separate his own soul from his body and send it to the upper realms of light or the nether regions of darkness. Now, although a particular individual inherits the shaman’s office from his father, he receives no formal instruction nor does he make any active preparation for his mission. His call comes in the form of a sudden paroxysm. He is seized with a feeling of languor and a fit of violent convulsions, with abnormal yawning, and a powerful pressure on the chest, which causes him to utter inarticulate screams. He begins to shiver with cold, rolls his eyes, suddenly leaps up and madly circles about until he falls down covered with perspiration and writhing in epileptic spasms on the ground. His members are devoid of sensation, his hands grasp without discrimination red-hot iron, knives, pins; he swallows such objects without suffering the slightest injury, and again ejects them from his mouth. Finally, the prospective seer seizes a shaman’s drum and assumes the shaman’s office. Disobedience to the spirit’s call would spell disaster, madness and death amidst the most horrible tortures.[2-i]

The naïve reaction to this narrative on the part of common sense in the familiar form of common ignorance will probably be that the European traveler who is our authority is a very gullible individual if he believed his native informant’s statements. How can an individual be seized with such a spasm as that described? How is it possible for him to become devoid of sensation? Nevertheless, nothing is more certain than that the account given is substantially correct. It is simply a particular form of nervous affliction very common throughout Siberia and attested by dozens of trustworthy eyewitnesses.[3-i] This Arctic hysteria, as it has been misnamed (for there is nothing distinctively Arctic about it), manifests itself principally in two ways. Either the individual falls victim to an indiscriminate mania for mimicking the acts of others; or he is seized with the sort of paroxysm described for the Turkish shaman. Nothing is clearer than that in neither case is there usually conscious deception. Sometimes the imitation mania subjects the sufferer to ridicule and pain, as when an old woman in imitation of a Cossack, seized a salmon with her teeth, ran up a hill and down again, unable to prevent herself from plunging into the water, though normally she was barely able to walk. Similarly, the numerous hysterical individuals of the other type who do not become inspired shamans cannot possibly derive any benefit from their fits.

Abnormal psychology here steps in and teaches us that such trances are involuntary and not the result of fraud, that they occur in our own civilization and are accompanied with extraordinary lack of sensibility to pain, in short, psychiatry classifies the observed phenomena and tells us what we are really dealing with. It prevents a misconception alike of the shaman’s activities and of the attitude of his people towards him.

When, however, abnormal psychology has so far enlightened us, it has by no means exhausted even the purely subjective aspect of the case. How does the prospective shaman seized with his fit know about the shamanistic drum that forms a necessary accessory of his office? How does he know what mode of activity is expected from him? These are not things which he can get directly from his trance for we shall hardly accept the aboriginal theory that he is inspired by the ancestral spirits. He can derive his knowledge, however informally, only as the member of a group holding certain definite views as to the shamanistic office. The cultural phenomenon, then, even on its psychological side, comprises a very appreciable plus over and above the