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.