From an obscure text called The Urantia Book that explains slavery in our society:
Slavery as a Factor in Civilization
Primitive man never hesitated to enslave his fellows. Woman was the first slave, a family slave. Pastoral man enslaved woman as his inferior sex partner. This sort of sex slavery grew directly out of man’s decreased dependence upon woman.
Not long ago enslavement was the lot of those military captives who refused to accept the conqueror’s religion. In earlier times captives were either eaten, tortured to death, set to fighting each other, sacrificed to spirits, or enslaved. Slavery was a great advancement over massacre and cannibalism.
Enslavement was a forward step in the merciful treatment of war captives. The ambush of Ai, with the wholesale slaughter of men, women, and children, only the king being saved to gratify the conqueror’s vanity, is a faithful picture of the barbaric slaughter practiced by even supposedly civilized peoples. The raid upon Og, the king of Bashan, was equally brutal and effective. The Hebrews “utterly destroyed” their enemies, taking all their property as spoils. They put all cities under tribute on pain of the “destruction of all males.” But many of the contemporary tribes, those having less tribal egotism, had long since begun to practice the adoption of superior captives.
The hunter, like the American red man, did not enslave. He either adopted or killed his captives. Slavery was not prevalent among the pastoral peoples, for they needed few laborers. In war the herders made a practice of killing all men captives and taking as slaves only the women and children. The Mosaic code contained specific directions for making wives of these women captives. If not satisfactory, they could be sent away, but the Hebrews were not allowed to sell such rejected consorts as slaves – that was at least one advance in civilization. Though the social standards of the Hebrews were crude, they were far above those of the surrounding tribes.
The herders were the first capitalists; their herds represented capital, and they lived on the interest – the natural increase. And they were disinclined to trust this wealth to the keeping of either slaves or women. But later on they took male prisoners and forced them to cultivate the soil. This is the early origin of serfdom – man attached to the land. The Africans could easily be taught to till the soil; hence they became the great slave race.
Slavery was an indispensable link in the chain of human civilization. It was the bridge over which society passed from chaos and indolence to order and civilized activities; it compelled backward and lazy peoples to work and thus provide wealth and leisure for the social advancement of their superiors.
The institution of slavery compelled man to invent the regulative mechanism of primitive society; it gave origin to the beginnings of government. Slavery demands strong regulation and during the European Middle Ages virtually disappeared because the feudal lords could not control the slaves. The backward tribes of ancient times, like the native Australians of today, never had slaves.
True, slavery was oppressive, but it was in the schools of oppression that man learned industry. Eventually the slaves shared the blessings of a higher society which they had so unwillingly helped create. Slavery creates an organization of culture and social achievement but soon insidiously attacks society internally as the gravest of all destructive social maladies.
Modern mechanical invention rendered the slave obsolete. Slavery, like polygamy, is passing because it does not pay. But it has always proved disastrous suddenly to liberate great numbers of slaves; less trouble ensues when they are gradually emancipated.
Today, men are not social slaves, but thousands allow ambition to enslave them to debt. Involuntary slavery has given way to a new and improved form of modified industrial servitude.
While the ideal of society is universal freedom, idleness should never be tolerated. All able-bodied persons should be compelled to do at least a self-sustaining amount of work.
Modern society is in reverse. Slavery has nearly disappeared; domesticated animals are passing. Civilization is reaching back to fire – the inorganic world – for power. Man came up from savagery by way of fire, animals, and slavery; today he reaches back, discarding the help of slaves and the assistance of animals, while he seeks to wrest new secrets and sources of wealth and power from the elemental storehouse of nature.