loom, the second the melting of metal ore and the use of metals in manufacture. Copper, tin, and their alloy, bronze, were the most essential of them. Bronze furnished tools and weapons, but could not displace stone implements. Only iron could have done that, but the production of iron was as yet un- known. Gold and silver were already used for orna- ment and decoration, and must have been far more precious than copper and bronze.
The increase of production in all branches—stock raising, agriculture, domestic handicrafts—enabled human labor power to produce more than was necessary for its maintenance. It increased at the same time the amount of daily work that fell to the lot of every member of a gens, a household, or a single family. The addition of more labor power became desirable. It was furnished by war; the captured enemies were transformed into slaves. Under the given historical conditions, the first great division of social labor, by increasing the productivity of labor, adding to the wealth, and enlarging the field of productive activity, necessarily carried slavery in its wake. Out of the first great division of social labor arose the first great division of society into two classes: masters and servants, exploiters and exploited.
How and when the herds were transferred from the collective ownership of the tribe or gens to the proprietorship of the heads of the families, is not known to us. But it must have been practically accomplished in this stage. The herds and the other new objects of wealth brought about a revolution in the family. Procuring the means of existence had always been the man's business. The tools of production were manufactured and owned by him. The herds were the new tools of production, and their taming and tending was his work. Hence he owned
