Now observe, a change gradually occurs, a change from the communal possession of land to a system of the individual possession of land, and force is the sole cause of this change. External aggression has initiated militant activity, while, in the process of frequent resistance to invasion, and frequent aggression upon others, there is produced the class inequalities which distinguish a militant type of society and a system allowing of individual land-ownership. Land becomes private property in the hands of the bold and crafty, who compel the cultivation of the soil by the landless men of the group, and by prisoners of war spared on condition that they perform hard labour. The institution of slavery thus becomes established, and it is a leading factor in the promotion of civilization. Lords of the soil spend their energies in warlike activities, whilst protecting their slaves and serfs at labour. The produce of that labour is appropriated by the dominant class, and used for its own particular benefit. Its requirements extend much beyond the mere necessaries of existence that it yields to the workers, and slowly there uprises a new form of labour and a large class of labourers, producing a variety of commodities to gratify the desires of pomp-loving, barbaric chiefs. Now this class, the labour of which is wholly absorbed by the chiefs, must be fed from the produce of the land. How is this accomplished? The chiefs, while exacting hard labour from the slaves and serfs, yield them only a bare living. But the proceeds of their labour, over and above the bare living of the producers, is very considerable. There is therefore a large surplus, which, appropriated by the chiefs as rent, is the source of their power. With it they support a large class of landless men engaged in ministering to their own specific wants. Moreover, this class groups itself around the castle of the chiefs, which are filled with military retainers, and here we have the beginnings of towns. The town population increases steadily with the increase of the surplus produce from land under better conditions of cultivation. Markets and stores are instituted, and a commercial system is introduced. Barter gives way to the use of money, and the entire social organism expands and becomes more complex. Anon, slavery disappears. But workers on the land—always the most necessary social units—remain poor as before. Competitors for work, in danger of starving, drive no hard bargain with masters who are in full possession of the soil, and able to forbid their growing even the simple fruits and grain required for a meagre living. For food enough to live, they readily pledge the labour of their whole lives, and since nature’s recompense for labour is liberal, there is an abundant surplus produce for landowners to grasp and employ as they choose. Into the towns it is sent, and there it stimulates progress—mental and material—and creates new departures in social life.