Non-economic purposes, slaves kept for, [424].
Ochenkowski, Dr. W. von, on medieval England, [359], [363] sqq.;
on money economy and the condition of the rural classes, [362].
Oppenheimer, Dr. F., on land and labour, [349];
on over-population, [369] note [2].
Orphans enslaved, [430].
Over-population, [369], [385].
Pastoral nomadism, considered favourable to the growth of slavery, [173].
Pastoral tribes, definition of term, [176];
have little use for slave labour, [267];
often employ free labourers, [268] sqq.;
subject other tribes, [276] sqq.;
have closed resources, [386].
Patriarchal theory, [26].
Pawns see Debtor-slaves.