Connection in space is a particularly cogent argument in favor of diffusion, because of its powerful presumption of accompanying communication. When several hundred Indian tribes without a break in their ranks between Quebec and Argentina cultivate maize, it would be absurd to dream of each of them having originated the domestication of the plant for itself. To be sure, it is logically conceivable that maize agriculture was independently developed by two or three of the most advanced tribes of the hundreds and then became diffused until the two or three areas of dispersion met and coalesced into one greater area. Yet the principle that economy of explanation is the best would militate even against this interpretation as compared with diffusion from a single center, unless there were definite indications in favor of the multiple origin explanation. Such indications might be radically distinct types of the plant or of agricultural implements in several parts of the maize area.
So, when the tribes on the Alaskan and Siberian sides of Behring Sea relate similar Raven legends, the geographical proximity is so close that it would be pedantic to let the fact that two continents are involved stand in the way of an explanation by diffusion. Even where the distribution of a trait penetrates much farther into both America and Asia, as is true of the composite bow (§ [210]), the continuity of area leaves little doubt as to diffusion from a single center, especially since it is reinforced by other traits showing the same intercontinental distribution: the Magic Flight story, for instance. It is only when the areas are discrete as well as remote, when other similarities between them are few or absent, when their cultural backgrounds are radically dissimilar, as in the case of the couvade, that parallelism begins to knock at the door of interpretation with serious hope of admittance.
102. Universal Elements
When a culture trait is very ancient and of practically world-wide occurrence, it becomes difficult to estimate between diffusion and independent invention. The fire-drill, flint chipping, the bow and arrow, the doctrine of animism or belief in souls and spirits, sympathetic magic, are in this class. The very universality of these elements tends to obliterate tangible evidence as to their histories. A generation or two ago it was generally taken for granted that such devices and beliefs as these sprang more or less spontaneously out of the human mind as soon as man had traversed a certain short distance of the evolutionary road that led him away from the brutes. At present, anthropological opinion is more cautious about such assumptions. It is perhaps spontaneous enough for people in the habit of using tools to try to fashion them from stone if other materials be lacking, and easy for a nation accustomed to projectile weapons to invent the bow without ever having learned of it. But this is far from proving what a people without these habits might do. Intelligent as an ape is, and gifted with manual dexterity, it rarely enters his mind to throw a stone as a missile and never to split it into a knife or weapon. For all we know, it may have cost our ancestors untold mental energy to bring themselves to the point of fashioning their first stone implements; so much, indeed, that it is possible all of them did without until one more gifted or fortunate group made the difficult invention which was then imitated by the others. It is temptingly but fatally easy to project our habits of mind into primitive man—much easier to imagine ourselves in his position than to imagine him, without reference to ourselves, as he was. Animal psychologists have learned not to anthropomorphize, that is, endow the lower animals with specifically human mind processes. Anthropologists have learned to guard against the similar pitfall of interpreting low cultures by the standards of our own, of assuming that because a thing seems “natural” to us it must have seemed natural and therefore have been done by any savage. It is clear that what did not happen was for every tribe or race to originate for itself its fire-making, flint-chipping, bows, animism, and magic. It is conceivable that each of these culture products traces back to a single source in human history. There are authorities who have held this very opinion; some expressedly, others by implication. It is not necessary to go so far; in fact, wiser not to, because none of these matters is yet susceptible of real proof. But it does seem profitable to recognize the possibility of the truth of such views, and that the drift of accumulating knowledge and experienced interpretation is in their direction.
A simple consideration which has too often been neglected is that diffusion and imitation undisputedly do take place in culture on a vast scale. So far as independent developments occur, be that rarely or frequently, they are therefore sure to be more or less intertwined with disseminations. Even one particular device may be partly borrowed and partly modified or further developed by original effort. Still more intimate must be the combination of native and diffused elements in the whole culture of any people. To wage an abstract battle as between two opposite principles is sterile, when their manifestations are admittedly frequent for one and at least certain for the other. It is clearly more profitable to examine the associations and relations of diffusion and convergence, the conditions under which they supplement each other. Besides parallels springing up wholly independently, there are two ways in which their relations to diffusion may be conceived. An original single growth or wave of diffusion may differentiate into local or temporal modifications, which even after separation continue to develop along parallel lines or reconverge. Or, on the other hand, independent starts in similar direction may become merged in, or assimilated by, a subsequent diffusion.
103. Secondary Parallelism in the Indo-European Languages
Parallel growth secondary to a former unity and differentiation is illustrated by the Indo-European languages. All the known ancient forms of this speech family, Sanskrit, Avestan, Greek, Latin, Gothic, were highly inflecting and compounding. Their tendency was synthetic (§ [51], [57]).
Grammatical ideas such as voice, tense, number, case, were expressed by elements affixed to the word stem and incapable of a separate existence. For they will have loved Latin says ama-v-eru-nt. The -v- has the force of have, the -eru- of will, -nt of they; but none of these parts can be used alone, as their equivalents in English can be, or as in French ils auront aimé. The two latter languages are analytical. They break an idea into parts which they express by separate words that change form but little. They retain only fragments of conjugations and declensions. Sanskrit had eight noun cases, Latin six; English has only two, the subjective-objective and the possessive, and French only one, or rather no case-form at all.[15]
This development toward a more analytical form is not only traceable in several non-Indo-European speech families, such as Chinese and Malayo-Polynesian (§ [61]), but has gone on in all the branches of Indo-European. It is visible in the growth of English from Anglo-Saxon; of French, Spanish, and Italian from Latin; of modern from ancient Persian; of Hindi and Bengali from Sanskrit. True, some of these have been in contact, like the Germanic and Latin languages, and might therefore be imagined to have set one another an example, although there is little evidence that languages seriously influence each other’s forms. But many of the Indo-European idioms have not been in contact at all for thousands of years. The Germanic and the Indo-Iranic branches, for instance, must have separated at least four thousand years ago. For the greater part of this period, accordingly, the related but no longer communicating languages that have resulted in modern English and Bengali, to take only one instance, have independently driven toward the same goal of more and more analytical structure. It may well be that the hidden germ of this impulse lay implanted in the common Indo-European mother-tongue at the time of its differentiation five or more thousand years ago. But the movement of its daughters has certainly been an astoundingly parallel one.