Psychology, racial differences, geographical environment, have all proved inadequate for the interpretation of cultural phenomena. The inference is obvious. Culture is a thing sui generis which can be explained only in terms of itself. This is not mysticism but sound scientific method. The biologist, whatever metaphysical speculations he may indulge in as to the ultimate origin of life, does not depart in his workaday mood from the principle that every cell is derived from some other cell. So the ethnologist will do well to postulate the principle, Omnis cultura ex cultura.[1-iv] This means that he will account for a given cultural fact by merging it in a group of cultural facts or by demonstrating some other cultural fact out of which it has developed. The cultural phenomenon to be explained may either have an antecedent within the culture of the tribe where it is found or it may have been imported from without. Both groups of determinants must be considered.

The extraneous determinants of culture summed up under the heading of ‘diffusion’ or ‘contact of peoples’ have been repeatedly referred to in the preceding pages. A somewhat detailed examination seems desirable, for it is difficult to exaggerate their importance.

“Civilization,” says Tylor, “is a plant much oftener propagated than developed;”[2-iv] and the latest ethnographic memoir that comes to hand voices the same sentiment: “It is and has always been much easier to borrow an idea from one’s neighbors than to originate a new idea; and transmission of cultural elements, which in all ages has taken place in a great many different ways, is and has been one of the greatest promoters of cultural development.”[3-iv]

A stock illustration of cultural assimilation is that of the Japanese, who in the nineteenth century adopted our scientific and technological civilization ready-made, just as at an earlier period they had acquired wholesale the culture of China. It is essential to note that it is not always the people of lower culture who remain passive recipients in the process of diffusion. This is strikingly shown by the spread of Indian corn. The white colonist “did not simply borrow the maize seed and then in conformity with his already established agricultural methods, or on original lines, develop a maize culture of his own,” but “took over the entire material complex of maize culture” as found among the aborigines.[4-iv] The history of Indian corn also illustrates the remarkable rapidity with which cultural possessions may travel over the globe. Unknown in the Old World prior to the discovery of America, it is mentioned as known in Europe in 1539 and had reached China between 1540 and 1570.[5-iv]

The question naturally arises here, whether this process of diffusion, which in modern times is a matter of direct observation, could have been of importance during the earlier periods of human history when means of communication were of a more primitive order. So far as this point is concerned, we must always remember that methods of transportation progressed very slightly from the invention of the wheeled cart until the most recent times. As Montelius suggests, the periods of 1700 B. C. and 1700 A. D. differed far less in this regard than might be supposed on superficial consideration. Yet we know the imperfection of facilities for travel did not prevent dissemination of culture in historic times.

The great Swedish archÆologist has, indeed, given us a most fascinating picture of the commercial relations of northern Europe in earlier periods and their effect on cultural development.[6-iv] We learn with astonishment that in the ninth and tenth centuries of our era, trade was carried on with great intensity between the North of Europe and the Mohammedan culture sphere since tens of thousands of Arabic coins have been found on Swedish soil. But intercourse with remote countries dates back to a far greater antiquity. One of the most powerful stimuli of commercial relations between northern and southern Europe was the desire of the more southern populations to secure amber, a material confined to the Baltic region and occurring more particularly about Jutland and the mouth of the Vistula. Amber beads have been found not only in Swiss pile-dwellings[7-iv] but also in MycenÆan graves of the second millennium B. C. Innumerable finds of amber work in Italy and other parts of southern Europe prove the importance attached to this article, which was exchanged for copper and bronze. The composition of Scandinavian bronzes indicates that their material was imported not from England but from the faraway regions of central Europe. That bronze was not of indigenous manufacture is certain because tin does not occur in Sweden at all while the copper deposits of northern Scandinavia remained untouched until about 1500 years after the end of the Bronze Age. Considering the high development of the bronze technique in Scandinavia and the fact that every pound of bronze had to be imported from without, it would be difficult to exaggerate the extent of contact with the southern populations. But intercourse was not limited to the South. For example, Swedish weapons and implements have been discovered in Finland. Again, crescent-shaped gold ornaments of Irish provenance have been found in Denmark, while a Swedish rock-painting represents with painstaking exactness a type of bronze shield common at a certain prehistoric period of England.

Montelius shows that historical connections of the type so amply attested for the Bronze Age also obtained in the preceding Neolithic era. Swedish hammers of stone dating back to the third pre-Christian millennium and flint daggers have been found in Finland, and earthenware characteristic of Neolithic Scandinavia also turns up on the Baltic coast of Russia. Stone burial cists with a peculiar oval opening at one end occur in a limited section of southwestern Sweden and likewise in England. Since such monuments have been discovered neither in other parts of Sweden nor in Jutland or the Danish islands, they point to a direct intercourse between Britain and western Sweden at about 2,000 B. C. A still older form of burial unites Scandinavia with other parts of the continent. Chambers built up of large stones set up edgewise and reaching from the floor to the roof, the more recent ones with and the older without a long covered passage, are highly characteristic of Sweden, Denmark, the British Isles, and the coasts of Europe from the Vistula embouchure to the coasts of France and Portugal, of Italy, Greece, the Crimea, North Africa, Syria, and India. Specific resemblances convince the most competent judges that some, at least, of these widely diffused ‘dolmens’ are historically connected with their Swedish equivalents, and since the oldest of these Northern chambers go back 3,000 years before our era, we thus have evidence of cultural diffusion dating back approximately five millennia.

It is highly interesting to trace under Montelius’ guidance the development of culture as it seems to have actually taken place in southern Sweden. Beginning with the earliest periods, we find the coastal regions inhabited by a population of fishermen and hunters. At a subsequent stage coarse pottery appears with articles of bone and antler, and there is evidence that the dog has become domesticated. In the later Neolithic era perfectly polished stone hammers and exquisitely chipped flint implements occur, together with indications that cattle, horses, sheep and pigs are domesticated and that the cultivation of the soil has begun. Roughly speaking, we may assume that the culture of Scandinavia at the end of the Stone Age resembled in advancement that of the agricultural North American and Polynesian tribes as found by the first European explorers. We may assume a long period of essentially indigenous cultural growth followed towards its close by intimate relations with alien populations. Nevertheless, it was the more extensive contact of the Bronze period that rapidly raised the ancestral Swedes to a cultural position high above a primitive level, with accentuation of agriculture, the use of woolen clothing, and a knowledge of metallurgy. It was again foreign influence that later brought the knowledge of iron and in the third century of our era transformed the Scandinavians into a literary people, flooded their country with art products of the highest then existing Roman civilization, and ultimately introduced Christianity.

The case of Scandinavian culture is fairly typical. We have first a long-continued course of leisurely and relatively undisturbed development, which is superseded by a tremendously rapid assimilation of cultural elements from without. Through contact with tribes possessing a higher civilization the ancient Scandinavians came to participate in its benefits and even to excel in special departments of it, such as bronze work, which from lack of material, they would have been physically incapable of developing unaided. Diffusion was the determinant of Scandinavian cultural progress from savagery to civilization.

It is obvious that this insistence on contact of peoples as a condition of cultural evolution does not solve the ultimate problem of the origin of culture. The question naturally obtrudes itself: If the Scandinavians obtained their civilization from the Southeast, how did the Oriental cultures themselves originate? Nevertheless, when we examine these higher civilizations of the Old World, we are again met with indubitable evidence that one of the conditions of development is the contact of peoples and the consequent diffusion of cultural elements. This appears clearly from a consideration of the ancient civilizations of Egypt, Babylonia, and China.

We now have abundant evidence for a later Stone Age in Egypt with an exceptionally high development of the art of chipping, as well as specimens of pottery and other indications of a sedentary mode of life. About 5,000 B. C. this undisturbed evolution began to suffer from a series of migrations of West Asiatic tribes, bringing in their wake a number of cultivated plants and domesticated animals, as well as various other features which possibly included the art of smelting copper, while the ceramic ware of the earlier period agrees so largely with that of Elam in what is now southern Persia that a cultural connection seems definitely established.

If from Egypt we turn to the most probable source of alien culture elements found there, viz., to the region of Mesopotamia, possibly the oldest seat of higher civilization in Asia, we find again that the culture of Babylonia under the famous lawgiver Hammurabi (about 2,000 B. C.) is not the product of purely indigenous growth but represents the resultant of at least two components, that of the Sumerian civilization of southern Babylonia and the Accadian culture of the North. It is certain that the Accadians adopted the art of writing from the Sumerians and were also stimulated by this contact in their artistic development. The evolution of Sumerian civilization is lost in obscurity but on the basis of well-established historical cases we should hesitate to assign to them an exclusively creative, and to other populations an exclusively receptive, rÔle. We may quite safely assume that the early splendor of Sumerian civilization was also in large part due to stimuli received through foreign relations. That cultural elements of value may be borrowed from an inferior as well as from a higher level, has already been exemplified by the case of maize. It is also, among other things, illustrated by the history of the Chinese.

The Chinese have generally been represented as developing in complete isolation from other peoples. This traditional conception, however, breaks down with more intimate knowledge. Dr. Laufer has demonstrated that Chinese civilization, too, is a complex structure due to the conflux of distinct cultural streams. As an originally inland people inhabiting the middle and lower course of the Yellow River, they gradually reached the coast and acquired the art of navigation through contact with Indo-Chinese seafarers. Acquaintance with the northern nomads of Turkish and Tungus stock led to the use of the horse, donkey and camel, as well as the practice of felt and rug weaving, possibly even to the adoption of furniture and the iron technique.[8-iv] Most important of all, it appears that essentials of agriculture, cattle-raising, metallurgy and pottery, as well as less tangible features of civilization are common to ancient China and Babylonia, which forces us to the conclusion that both the Chinese and Babylonian cultures are ramifications from a common Asiatic sub-stratum. It would be idle to speculate as to the relative contributions of each center to this ancient cultural stock. The essential point is that the most ancient Asiatic civilizations of which we have any evidence already indicate close contact of peoples and the dispersal of cultural elements.

Contact of peoples is thus an extraordinary promoter of cultural development. By the free exchange of arts and ideas among a group of formerly independent peoples, a superiority and complexity is rendered possible which without such diffusion would never have occurred. The part played in this process by the cruder populations must not be underestimated. They may contribute both actively and passively; actively, by transmitting knowledge independently acquired, as in the case of the felt technique the Chinese learned from the northern nomads; passively, by forming a lower caste on which the economic labors devolve and thus liberating their conquerors for an enlarged activity in the less utilitarian spheres of culture.

Nevertheless, before peoples can communicate their cultures to others with whom they come into contact, they must first evolve these cultures. The question thus remains, What determines this evolution? In order to gain a proper perspective in this matter, we must for a moment consider the progress of human civilization as a whole. ArchÆological research shows that the modern era of steel and iron tools was preceded by an age of bronze and copper implements, which in turn was preceded by a stone age subdivided into a more recent period of polished, and an earlier of merely chipped, stone tools. Now the chronological relations of these epochs are extremely suggestive. The very lowest estimate by any competent observer of the age of PalÆolithic man in Europe sets it at 50,000 years;[9-iv] since this is avowedly the utmost minimum value that can be assigned on geological grounds, we may reasonably assume twice that figure for the age of human culture generally. Using the rough estimate permissible in discussions of this sort, we may regard the end of the PalÆolithic era as dating back about 15,000 years ago. In short, for more than eight-tenths of its existence, the human species remained at a cultural level at best comparable with that of the Australian. We may assume that it was during this immense space of time that dispersal over the face of the globe took place and that isolation fixed the broader diversities of language and culture, over and above what may have been the persisting cultural sub-stratum common to the earliest undivided human group. The following Neolithic period of different parts of the globe terminated at different times and had not been passed at all by most of the American aborigines and the Oceanians at the time of their discovery. However, from the broader point of view here assumed, it was not relieved by the age of metallurgy until an exceedingly recent past. The earliest estimate I have seen does not put the event back farther than 6000 B. C. even in Mesopotamia. During nine-tenths of his existence, then, man was ignorant of the art of smelting copper from the ore. Finally, the iron technique does not date back 4,000 years; it took humanity ninety-six hundredths of its existence to develop this art.

We may liken the progress of mankind to that of a man a hundred years old, who dawdles through kindergarten for eighty-five years of his life, takes ten years to go through the primary grades, then rushes with lightning rapidity through grammar school, high school and college. Culture, it seems, is a matter of exceedingly slow growth until a certain ‘threshold’ is passed, when it darts forward, gathering momentum at an unexpected rate. For this peculiarity of culture as a whole, many miniature parallels exist in special subdivisions of culture history. Natural science lay dormant until Kepler, Galileo and Newton stirred it into unexampled activity, and the same holds for applied science until about a century ago.

This discontinuity of development receives strong additional illustration from a survey of special subdivisions of ancient culture. Though the PalÆolithic era certainly preceded the later Stone Age, archÆologists have hitherto failed to show the steps by which the later could develop out of the earlier. This gap may, of course, be due merely to our lack of knowledge. Yet when we take subdivisions of the PalÆolithic period, the same fact once more confronts us. There is no orderly progression from Solutrean to Magdalenian times. The highly developed flint technique of the former dwindles away in the latter and its place is taken by what seems a spontaneous generation of bone and ivory work, with a high development of realistic art.

In view of the evidence, it seems perfect nonsense to say that early European civilization, by some law inherent in the very nature of culture, developed in the way indicated by archÆological finds. Southern Scandinavia could not possibly have had a bronze age without alien influence. In this case, discontinuity was the result of cultural contact. It may be that the lack of definite direction observed throughout the Stone Age may in part be due to similar causes, the migrations and contact of different peoples, as Professor Sollas suggests. But it is important to note that discontinuity is a necessary feature of cultural progress. It does not matter whether we can determine the particular point in the series at which the significant trait was introduced. It does not matter whether, as I have suggested in the discussion of racial features, the underlying causes of the phenomena proceed with perfect continuity. Somewhere in the observed cultural effects there is the momentous innovation that leads to a definite break with the past. From a broad point of view, for example, it is immaterial whether the doctrine of evolution clings to the name of the younger or the elder Darwin, to Lamarck or St. Hilaire; the essential thing is that somehow the idea originated, and that when it had taken root it produced incalculable results in modern thought.

If culture, even when uninfluenced by foreign contact, progresses by leaps and bounds, we should naturally like to ascertain the determinants of such ‘mutations.’ In this respect, the discontinuity of indigenous evolution differs somewhat from that connected with cultural development due to diffusion. It was absolutely impossible that Scandinavia should produce bronze in the absence of tin. But a priori it is conceivable that an undisturbed culture might necessarily develop by what biologists call ‘orthogenetic evolution’, i.e., in a definite direction through definite stages. This is, indeed, what is commonly known as the classical scheme of cultural evolution, of which men like Morgan are the protagonists. Now, how do the observed facts square with this theoretical possibility?

As Professor Boas and American ethnologists generally have maintained,[10-iv] many facts are quite inconsistent with the theory of unilinear evolution. That theory can be tested very simply by comparing the sequence of events in two or more areas in which independent development has taken place. For example, has technology in Africa followed the lines ascertained for ancient Europe? We know today that it has not. Though unlike southern Scandinavia, the Dark Continent is not lacking in copper deposits, the African Stone Age was not superseded by a Copper Age, but directly by a period of Iron. Similarly, I have already pointed out that the possession of the same domesticated animals does not produce the same economic utilization of them while the Tungus rides his reindeer, other Siberians harness their animals to a sledge; the Chinaman will not milk his cattle, while the Zulu’s diet consists largely of milk. That a particular innovation occurred at a given time and place is, of course, no less the result of definite causes than any other phenomenon of the universe. But often it seems to have been caused by an accidental complex of conditions rather than in accordance with some fixed principle.

For example, the invention of the wheel revolutionized methods of transportation. Now, why did this idea develop in the Old World and never take root among the American Indians? We are here face to face with one of those ultimate data that must simply be accepted like the physicist’s fact that water expands in freezing while other substances contract. So far as we can see, the invention might have been made in America as well as not; and for all we know it would never have been made there until the end of time. This introduces a very important consideration. A given culture is, in a measure, at least, a unique phenomenon. In so far as this is true it must defy generalized treatment, and the explanation of a cultural phenomenon will consist in referring it back to the particular circumstances that preceded it. In other words, the explanation will consist in a recital of its past history; or, to put it negatively, it cannot involve the assumption of an organic law of cultural evolution that would necessarily produce the observed effect.

Facts already cited in other connections may be quoted again by way of illustration. When a copper implement is fashioned not according to the requirements of the material, but in direct imitation of preËxisting stone patterns, we have an instance of cultural inertia: it is only the past history of technology that renders the phenomena conceivable. So the unwieldy Chukchee tent, which adheres to the style of a pre-nomadic existence, is explained as soon as the past history of the tribe comes to light.

Phenomena that persist in isolation from their original context are technically known as ‘survivals’, and form one of the most interesting chapters of ethnology. One or two additional examples will render their nature still clearer. The boats of the Vikings were equipped for rowing as well as for sailing. Why the superfluous appliances for rowing, which were later dropped? As soon as we learn that the Norse boats were originally rowboats and that sails were a later addition, the rowing equipment is placed in its proper cultural setting and the problem is solved. Another example may be offered from a different phase of life. Among the Arapaho Indians there is a series of dance organizations graded by age. Membership is acquired by age-mates at the same time, each receiving the requisite ceremonial instructions from some older man who passed through the dance in his day. These older men, who are paid for their services by the candidates, may belong to any and all of the higher organizations. Oddly enough, each group of dancers is assisted by a number of ‘elder brothers’, all of whom rank them by two grades in the series of dancers. This feature is not at all clear from the Arapaho data alone. When, however, we turn to the Hidatsa Indians, with whom there is evidence this system of age-societies originated, we find that here the youngest group of men does not buy instructions from a miscellaneous assemblage of older men, but buys the dance outright from the whole of the second grade; this group, in order to have the privilege of performing a dance, must buy that of the third grade, and so on. In all these purchases the selling group seeks to extort the highest possible price while the buyers try to get off as cheaply as possible and are aided by the second higher group, i.e., the group just ranking the sellers. Here the sophomore-senior versus freshman-junior relationship is perfectly intelligible; both the freshman and the junior, to pursue the analogy, bear a natural economic hostility against the sophomore, and vice versa. The Arapaho usage is intelligible as a survival from this earlier Hidatsa condition.

Our own civilization is shot through with survivals, so that further illustrations are unnecessary. They suggest, however, another aspect of our general problem. Of course, in every culture different traits are linked together without there being any essential bond between them. An illustration of this type of association is that mentioned by Dr. Laufer for Asiatic tribes, viz., that all nations which use milk for their diet have epic poems, while those which abstain from milk have no epic literature. This type of chance association, due to historical causes, has been discussed by Dr. Wissler[11-iv] and Professor Czekanowski.[12-iv] But survivals show that there may be an organic relation between phenomena that have become separated and are treated as distinct by the descriptive ethnologist. In such cases, one trait is the determinant of the other, possibly as the actually preceding cause, possibly as part of the same phenomenon in the sense in which the side of a triangle is correlated with an angle.

A pair of illustrations will elucidate the matter. Primitive terms of relationship often reveal characteristic differences of connotation from their nearest equivalents in European languages. On the other hand, they are remarkably similar not only among many of the North American Indians but also in many other regions of the globe, such as Australia, Oceanica, Africa. The most striking peculiarity of this system of nomenclature lies in the inclusiveness of certain terms. For example, the word we translate as ‘father’ is applied indiscriminately to the father, all his brothers, and some of his male cousins; while the word for ‘mother’ is correspondingly used for the mother’s sisters and some of their female cousins. On the other hand, paternal and maternal uncle or aunt are rigidly distinguished by a difference in terminology. As Morgan divined and Tylor clearly recognized, this system is connected with the one-sided exogamous kin organization by which an individual is reckoned as belonging to the exogamous social group of one, and only one, of his parents. The terminology that appears so curious at first blush then resolves itself very simply into the method of calling those members of the tribe who belong to the father’s social group and generation by the same term as the father, while the maternal uncles, who must belong to another group because of the exogamous rule, are distinguished from the father. In short, the terminology simply expresses the existing social organization. In a world-wide survey of the field Tylor found that the number of peoples who use the type of nomenclature I have described and are divided into exogamous groups, is about three times that to be expected on the doctrine of chances: in other words, the two apparently distinct phenomena are causally connected.[13-iv] This interpretation has recently been forcibly advocated by Dr. Rivers, and I have examined the North American data from this point of view. It developed, as a matter of fact, that practically all the tribes with exogamous ‘clans’, i.e., matrilineal kin groups, or exogamous ‘gentes’, i.e., patrilineal kin groups, had a system of the type described, while most of the tribes lacking such groups also lacked the nomenclature in question. Accordingly, it follows that there is certainly a functional relation between these phenomena, although it is conceivable that both are functionally related to still other phenomena, and that the really significant relationship remains to be determined.

As a linked illustration, the following phenomena may be presented. Among the Crow of Montana, the Hopi of Arizona, and some Melanesian tribes, the same term is applied to a father’s sister and to a father’s sister’s daughter; indeed, among the Crow and the Hopi the term is extended to all the female descendants through females of the father’s sister ad infinitum. Such a usage is at once intelligible from the tendency to call females of the father’s group belonging to his and younger generations by a single term, regardless of generation, if descent is reckoned through the mother, for in that case, and that case only, will the individuals in question belong to the same group. And the fact is that in each of the cases mentioned, group affiliation is traced through the mother, while I know of not a single instance in which paternal descent coexists with the nomenclatorial disregard of generations in the form described.

My instances show, then, that cultural traits may be functionally related, and this fact renders possible a parallelism, however limited, of cultural development in different parts of the globe. The field of culture, then, is not a region of complete lawlessness. Like causes produce like effects here as elsewhere, though the complex conditions with which we are grappling require unusual caution in definitely correlating phenomena. It is true that American ethnologists have shown that in several instances like phenomena can be traced to diverse causes; that, in short, unlike antecedents converge to the same point. However, at the risk of being anathematized as a person of utterly unhistorical mentality, I must register my belief that this point has been overdone and that the continued insistence on it by Americanists is itself an illustration of cultural inertia. Indeed, the vast majority of so-called convergencies are not genuine, but false analogies due to our throwing together diverse facts from ignorance of their true nature, just as an untutored mind will class bats with birds, or whales with fish. When, however, rather full knowledge reveals not superficial resemblance but absolute identity of cultural features, it would be miraculous, indeed, to assume that such equivalence somehow was shaped by different determinants. When a Zulu of South Africa, an Australian, and a Crow Indian all share the mother-in-law taboo imposing mutual avoidance on the wife’s mother and the daughter’s husband, with exactly the same psychological correlate, it is, to my mind, rash to decree without attempt to produce evidence that this custom must, in each case, have developed from entirely distinct motives. To be sure, this particular usage has not yet, in my opinion, been satisfactorily accounted for. Nevertheless, in contradistinction to some of my colleagues and to the position I myself once shared, I now believe that it is pusillanimous to shirk the real problem involved, and that in so far as any explanation admits the problem, any explanation is preferable to the flaunting of fine phrases about the unique character of cultural phenomena. When, however, we ask what sort of explanation could be given, we find that it is by necessity a cultural explanation. Tylor, e.g., thinks that the custom is correlated with the social rule that the husband takes up his abode with the wife’s relatives and that the taboo merely marks the difference between him and the rest of the family. We have here clearly one cultural phenomenon as the determinant of another.

It is not so difficult as might at first appear to harmonize the principle that a cultural phenomenon is explicable only by a unique combination of antecedent circumstances with the principle that like phenomena are the product of like antecedents. The essential point is that in either case we have past history as the determinant. It is not necessary that certain things should happen; but if they do happen, then there is at least a considerable likelihood that certain other things will also happen. Diversity occurs where the particular thing of importance, say the wheel, has been discovered or conceived in one region but not in another. Parallelism tends to occur when the same significant phenomenon is shared by distinct cultures. It remains true that in culture history we are generally wise after the event. A priori, who would not expect that milking must follow from the domestication of cattle?

When we find that a type of kinship terminology is determined by exogamy or matrilineal descent, we have, indeed, given a cultural explanation of a cultural fact; but for the ultimate problems how exogamy or maternal descent came about, we may be unable to give a solution. Very often we cannot ascertain an anterior or correlated cultural fact for another cultural fact, but can merely group it with others of the same kind. Of this order are many of the parallels that figure so prominently in ethnological literature. For example, that primitive man everywhere believes in the animation of nature seems an irreducible datum which we can, indeed, paraphrase and turn hither and thither for clearer scrutiny but can hardly reduce to simpler terms. All we can do is to merge any particular example of such animism in the general class after the fashion of all scientific interpretation. That certain tendencies of all but universal occurrence are characteristic of culture, no fair observer can deny, and it is the manifest business of ethnology to ascertain all such regularities so that as many cultural phenomena as possible may fall into their appropriate categories. Only those who would derive each and every trait similar in different communities of human beings from a single geographical source can ignore such general characteristics of culture, which may, in a sense, be regarded as determinants of specific cultural data or rather, as the principles of which these are particular manifestations.

Recently I completed an investigation of Plains Indian societies begun on the most rigorous of historical principles, with a distinct bias in favor of the unique character of cultural data. But after smiting hip and thigh the assumption that the North American societies were akin to analogous institutions in Africa and elsewhere, I came face to face with the fact that, after all, among the Plains Indians, as among other tribes, the tendency of age-mates to flock together had formed social organizations and thus acted as a cultural determinant.

Beyond such interpretative principles for special phases of civilization, there are still broader generalizations of cultural phenomena. One has been repeatedly alluded to under the caption of cultural inertia, or survival—the irrational persistence of a feature when the context in which it had a place has vanished. But culture is not merely a passive phenomenon but a dynamic one as well. This is strikingly illustrated in the assimilation of an alien cultural stimulus. As I have already pointed out, it is not sufficient to bring two cultures into contact in order to have a perfect cultural interpenetration. The element of selection enters in a significant way. Not everything that is offered by a foreign culture is borrowed. The Japanese have accepted our technology but not our religion and etiquette. Moreover, what is accepted may undergo a very considerable change. While the whole range of phenomena is extremely wide and cannot be dismissed with a few words, it appears fairly clear that generally the preËxisting culture at once seizes upon a foreign element and models it in accordance with the native pattern. Thus, the Crow Indians, who had had a pair of rival organizations, borrowed a society from the Hidatsa where such rivalry did not exist. Straightway, the Crow imposed on the new society their own conception, and it became the competitor of another of their organizations. Similarly the Pawnee have a highly developed star cult. Their folklore is in many regards similar to that of other Plains tribes, from which some tales have undoubtedly been borrowed. Yet in the borrowing these stories became changed and the same episodes which elsewhere relate to human heroes now receive an astral setting. The preËxisting cultural pattern synthetizes the new element with its own preconceptions.

Another tendency that is highly characteristic of all cultures is the rationalistic explanation of what reason never gave rise to. This is shown very clearly in the justification of existing cultural features or of opinions acquired as a member of a particular society. Hegel’s notion that whatever exists is rational and Pope’s ‘whatever is, is right’ have their parallels in primitive legend and the literature of religious and political partisanship. In the special form of justification employed we find again the determining influence of the surrounding cultural atmosphere. Among the Plains Indians almost everything is explained as the result of supernatural revelation; if a warrior has escaped injury in battle it is because he wore a feather bestowed on him in a vision; if he acquires a large herd of horses it is in fulfilment of a spiritistic communication during the fast of adolescence. In a community where explanations of this type hold sway, we are not surprised to find that the origin of rites, too, is almost uniformly traced to a vision and that even the most trivial alteration in ceremonial garb is not claimed as an original invention but ascribed to supernatural promptings. Thus, the existing culture acts doubly as the determinant of the explanation offered for a particular cultural phenomenon. It evokes the search for its own raison d’Être; and the type of interpretation called forth conforms to the explanatory pattern characteristic of the culture involved.

Culture thus appears as a closed system. We may not be able to explain all cultural phenomena or at least not beyond a certain point; but inasmuch as we can explain them at all, explanation must remain on the cultural plane.

What are the determinants of culture? We have found that cultural traits may be transmitted from without and in so far forth are determined by the culture of an alien people. The extraordinary extent to which such diffusion has taken place proves that the actual development of a given culture does not conform to innate laws necessarily leading to definite results, such hypothetical laws being overridden by contact with foreign peoples. But even where a culture is of relatively indigenous growth comparison with other cultures suggests that one step does not necessarily lead to another, that an invention like the wheel or the domestication of an animal occurs in one place and does not occur in another. To the extent of such diversity we must abandon the quest for general formulÆ of cultural evolution and recognize as the determinant of a phenomenon the unique course of its past history. However, there is not merely discontinuity and diversity but also stability and agreement in the sphere of culture. The discrete steps that mark culture history may not determine one another, but each may involve as a necessary or at least probable consequence other phenomena which in many instances are simply new aspects of the same phenomenon, and in so far forth one cultural element as isolated in description is the determinant or correlate of another. As for those phenomena which we are obliged to accept as realities without the possibility of further analysis, we can, at least, classify a great number of them and merge particular instances in a group of similar facts. Finally, there are dominant characteristics of culture, like cultural inertia or the secondary rationalization of habits acquired irrationally by the members of a group, which serve as broad interpretative principles in the history of civilization.

In short, as in other sciences, so in ethnology there are ultimate, irreducible facts, special functional relations, and principles of wider scope that guide us through the chaotic maze of detail. And as the engineer calls on the physicist for a knowledge of mechanical laws, so the social builder of the future who should seek to refashion the culture of his time and add to its cultural values will seek guidance from ethnology, the science of culture, which in Tylor’s judgment is ‘essentially a reformer’s science.’