Two secondary internal causes found in the second chapter have been also met with among pastoral tribes: slaves are sometimes employed in warfare, and sometimes for domestic labour to relieve the women of their task. Two new secondary factors have been found in this chapter: slaves are kept as a luxury; and sometimes the subjection of tribes as such, serving as a substitute for slavery, makes slavery proper superfluous.
With regard to the external causes it has been shown that the coercive power of pastoral tribes is not very strong, as they are nomadic and live in rather small groups; but this want is sometimes compensated for by the slave-trade and the neighbourhood of inferior races. The two latter circumstances may therefore rank as new external causes, the slave-trade taking the place of the existence of a homogeneous group. On the Pacific Coast of N. America it is the trade between tribes of the same culture, among pastoral nomads it is the trade with Arabia, etc.; but in either case it is the slave-trade that furthers the growth of slavery.
Recapitulation of the causes we have found up to the present.
| Furthering the growth of slavery. | Hindering the growth of slavery. | |
| I. Internal causes. | ||
| A. General. | 1º. Subsistence easily acquired and not dependent on capital. | 1º. Subsistence dependent on capital. |
| 2º. Subsistence not dependent on capital, but difficult to procure.[[291]] | ||
| B. Secondary economic: | 1º. Preserving of food. | 1º. Female labour making slave labour superfluous. |
| 2º. Trade and industry. | ||
| 3º. A high position of women. | 2º. Subjection of tribes as such. | |
| C. Secondary non-economic: | 1º. Slaves wanted for military purposes. | 1º. Militarism making slavery impossible. |
| 2º. Slaves kept as a luxury. | ||
| II. External causes: | 1º. Fixed habitations. | |
| 2º. Living in large groups. | ||
| 3º. Preserving of food[110]. | ||
| 4º. The slave-trade. | ||
| 5º. The neighbourhood of inferior races. | ||
[[292]]
[2] See above, pp. 127, 128, 131, and Baumann, p. 165. [↑]