It may be taken as a generalisation grounded in the instinctive endowment of mankind that the human sense of workmanship will unavoidably go on turning to account what there is in hand of technological knowledge, and so will in the course of time, by insensible gains perhaps, gradually change the technological scheme, and therefore also the scheme of customary canons of conduct answering to it; and in the absence of overmastering circumstances this sequence of change must, in a general way, set in the direction of great technological mastery. Something in the way of an “advance” in workmanlike mastery is to be looked for, in the absence of inexorable limitations of environment. The limitations may be set by the material circumstances or by circumstances of the institutional situation, but on the lower levels of culture the insurmountable obstacles to such an advance appear to have been those imposed by the material circumstances; although institutional factors have doubtless greatly retarded the advance in most cases, and may well have defeated it in many. In some of the known lower cultures such an impassable conjuncture in the affairs of technology has apparently been reached now and again, resulting in a “stationary state” of the industrial arts and of social arrangements, economic and otherwise. Such an instance of “arrested development” is afforded by the Eskimo, who have to all appearance reached the bounds of technological mastery possible in the material circumstances in which they have been placed and with the technological antecedents which they have had to go on. At the other extreme of the American continent the Fuegians and Patagonians may similarly have reached at least a provisional limit of the same nature; though such a statement is less secure in their case, owing to the scant and fragmentary character of the available evidence. So also the Bushmen, the Ainu, various representative communities of the Negrito and perhaps of the Dravidian stocks, appear to have reached a provisional limit--barring intervention from without. In these latter instances the decisive obstacles, if they are to be accepted as such, seem to lie in the human-nature of the case rather than in the material circumstances. In these latter instances the sense of workmanship, though visibly alert and active, appears to have been inadequate to carry out the technological scheme into further new ramifications for want of the requisite intellectual aptitudes,--a failure of aptitudes not in degree but in kind.