And where, as among the manufacturing classes, the functions discharged donot require the dispersion of citizens who are artificially assimilated,there is an aggregation of them in special localities, and a consequent increasein the definiteness of industrial divisions. If, now, we seek the causesof these segregations, considered as results of force and motion, we arebrought to the same general principle as before. This likeness produced inthe members of any class or sub-class by training, is an aptitude acquiredby them for satisfying their wants in like ways. That is, the occupationhas become to each a line of least resistance. Hence under that pressurewhich determines all men to activity these similarly -- modified social unitsare similarly affected, and tend to take similar courses. If, then, therebe any locality which, either by its physical peculiarities or by peculiaritieswrought on it during social evolution, is rendered a place where a certainkind of industrial action meets with less resistance than elsewhere, it followsfrom the law of direction of motion that those social units who have beenmoulded to this kind of industrial action, will be segregated by moving towardsthis place. If, for instance, the proximity of coal and iron mines to a navigableriver, gives to Glasgow an advantage in the building of iron-ships-if thetotal labour required to produce a given vessel, and get its equivalent infood and clothing, is less there than elsewhere; there is caused a concentrationof iron-ship builders at Glasgow, either by detention of the population bornto iron-ship building, or by immigration of those elsewhere engaged in it,or by both. The principle equally holds where the occupation is mercantileinstead of manufacturing. Stock-brokers cluster where the amount of effortto be severally gone through by them in discharging their functions, andobtaining their profits, is less than elsewhere. A local exchange havingonce been established, becomes a place where the resistance to be overcomeby each is smaller than in any other place; and, being like units under stressof common desires, pursuit of the course of least resistance by each involvestheir aggregation around this place.
Of course, with units so complex as those which constitute a society,and with forces so involved as those which move them, the resulting selectionsand separations must be far more entangled, or far less definite, than thosewe have hitherto considered. For men's likenesses being of various kinds,lead to various orders of segregation. There are likenesses of disposition,likenesses of taste, likenesses produced by education, likenesses that resultfrom class-habits, likenesses of political feeling; and it needs but to glanceround at the caste-divisions, the associations for philanthropic, scientific,and artistic purposes, the religious parties and social cliques, to see thatsome species of likeness among the component members of each body determinestheir union. Now the different segregative processes, by traversing one anotherand often by their indirect antagonism, more or less obscure one another'seffects, and prevent any one differentiated class from completely integrating.
But if this cause of incompleteness be borne in mind, social segregationswill be seen to conform to the same principle as all other segregations. §169. Can the general truth thus variously illustrated be deducedfrom the persistence of forte, in common with foregoing truths? Probablythe exposition at the beginning of the chapter will have led most readersto conclude that it can be so deduced.
