MOOT POINTS IN SOCIOLOGY 197
VI. The interaction of societies. The actions and reactions among the parts of a society tend either to assimilate or to differ- entiate. Whether it takes the form of trade, of intellectual com- merce, or of social intercourse, interaction ordinarily brings about a mutual modification of ideas and feelings in the direction of greater agreement, which results in a more perfect solidarity. Trade, however, by leading to the territorial division of labor, may pave the way for local differentiation, and it is furthermore possible that social intercourse by disclosing unsuspected elements of friction may inspire antagonism rather than harmony.
Far more momentous, however, are the interactions between a society and other groups and masses in its environment. These interactions take the form of interchanges of goods or of men, and of conflict.
The springing up of commerce between societies hitherto self-sufficing makes them dependent on one another for certain articles and so constitutes them an enlarged economic unit. Meanwhile the balance of occupations within each group is over- thrown, and the restoration of equilibrium may not occur without some institutional changes. Her trade with Europe is costing India her famous native arts and threatens those of Japan. In the fifteenth century the demand on the continent for English wool resulted in the conversion of fields into sheep pastures, the inclosure of much common land, the raising of rents, the eviction of customary tenants, a plethora of labor, and a freeing of the villeins from their ancient bondage. Nieboer tells us:
The slow agricultural revolution, which rendered their services less useful to the manorial lords, gradually set the villeins free by removing the interest their masters had in retaining their hold upon them.
Again, it is the rise of a foreign commerce that permits slavery to expand to wholesale proportions. Negro slavery would never have developed to such a scale and gotten such a hold upon our South had not Europe stood ready to absorb immense quantities of the plantation staple, cotton, and to supply those manufac- tures which slave labor is so unfitted to produce. Furthermore, if two societies that begin to exchange are unequally supplied with the money metal and are therefore on different price levels, the
