Every man aims to pass from desire to satisfaction with the least possible hindrance--follows the line of least resistance. Either the shortest path, or the path which presents fewest impediments, is that which he chooses; and the like applies to courses of conduct at large: he does not use great effort to satisfy a want when small effort will do. Given his surroundings and the occupation he chooses, when choice is possible, is that which promises a satisfactory livelihood with the least tax on such powers as he has, bodily and mental--is the easiest to his particular nature, all things considered. What holds of individuals holds of masses of individuals; and hence the inhabitants of a tract offering facilities for a particular occupation fall into that occupation. In § 732 of the _Principles of Sociology_ I have given from various countries illustrations of the ways in which local conditions determine the local industries:--instance among ourselves mining districts where there are coal, ironstone, lead, slate; wheat-growing districts and pastoral districts; fruit and hop districts; districts for weavers, stockingers, workers in iron; places for shipbuilding, importing, fishing, etc.: showing that certain sections of the population become turned into organizations for the production of certain commodities, without reference to the directive agency of any man. So in each case is it with the various classes of merchants, shopkeepers, professional men, etc., who in each of these centers minister to those engaged in its special industries: nobody ordering them to come or to go.