[6] Ibid. p. 199 sqq.
Of the pastoral tribes referred to in Dr. Nieboer’s list only one half keep slaves, and among some of these slave-keeping is said to be a mere luxury. To pastoral peoples, as such, slave labour is of little moment. Among them subsistence depends much more on capital than on labour, and for the small amount of work which is required free labourers are easily procured. As Dr. Nieboer observes, “among people who live upon the produce of their cattle, a man who owns no cattle, i.e. no capital, has no means of subsistence. Accordingly, among pastoral tribes we find rich and poor men; and the poor often offer themselves as labourers to the rich.”[7] Pastoral peoples have thus no strong motives for making slaves, but at the same time “there are no causes preventing them from keeping slaves. These tribes are, so to speak, in a state of equilibrium; a small additional cause on either side turns the balance. One such additional cause is the slave-trade; another is the neighbourhood of inferior races.” All those pastoral peoples who keep slaves live in districts where an extensive slave-trade has for a long time been carried on. The slaves are often purchased from slave-traders, and in several cases they belong to an inferior race.[8]
[7] See also Hildebrand, op. cit. p. 38 sq.
[8] Nieboer, op. cit. p. 261 sqq.
Among agricultural peoples slavery prevails more extensively; further, it is more common among such tribes as subsist chiefly by agriculture than among incipient agriculturists, who still depend on hunting or fishing for a large portion of their food. In primitive agricultural communities nobody voluntarily serves another, because subsistence is independent of capital and easy to procure. “All freemen in new countries,” says Mr. Bagehot, “must be pretty equal; every one has labour, and every one has land; capital, at least in agricultural countries (for pastoral countries are very different), is of little use; it cannot hire labour; the labourers go and work for themselves.”[9] Hence in such countries, if a man wants another to work for him, he must compel him to do it—that is, he must make him his slave. This holds true of most savage countries, namely, of all those in which there is much more fertile land than is required to be cultivated for the support of the actual population; but it does not hold true of all. Where every piece of land fit for cultivation has been appropriated, a man who owns no land cannot earn his subsistence independently of a landlord; hence free labourers are available, slaves are not wanted, and slavery is not likely to exist. And even where there are no poor persons, but everybody has a share in the resources of the country, the use of slaves cannot be great, since a man who owns a limited capital, or a limited quantity of land, can only employ a limited number of labourers. For instance, the absence of slavery in many Oceanic islands may be accounted for by the fact that all land had been appropriated, which led to a state of things inconsistent with slavery as a social system.[10]
[9] Bagehot, Physics and Politics, p. 72.
[10] Nieboer, op. cit. pp. 294-347, 420 sq.
These are the main conclusions at which Dr. Nieboer has arrived by means of much admirable and painstaking research. Most of them, I think, are undoubtedly correct; yet it seems to me that the influence of economic conditions upon the institution of slavery has perhaps been emphasised too much at the cost of other factors. The prevalence of slavery in a savage tribe and the extent to which it is practised must also depend upon the ability of the tribe to procure slaves from foreign communities and upon its willingness to allow its own members to be kept as slaves within the tribe. It may be very useful for a group of savages to have a certain number of slaves, and yet they may not have them, for the reason that no slaves are to be had. It is only in extraordinary cases that a person is allowed to enslave a member of his own community. Intra-tribal slavery is a question not only of economic but of moral concern, whilst extra-tribal slavery originally depends upon success in war.
We have reason to believe that the earliest source of slavery was war or conquest, and that slavery in many cases was a substitution for putting prisoners of war to death.[11] Savages, who have little mercy on their enemies, naturally make no scruple in reducing them to slavery whenever they find their advantage in doing so. Among existing savages, in fact, prisoners of war are very frequently enslaved.[12] They and their descendants, together with persons kidnapped or purchased from foreign tribes, seem generally to form by far the majority of the slave population in uncivilised countries.
[11] Cf. Millar, Origin of the Distinction of Ranks, p. 245; Jacob, Historical Inquiry into the Production and Consumption of the Precious Metals, i. 136; Buckle, Miscellaneous and Posthumous Works, iii. 413; Comte, Cours de philosophie positive, v. 186 sqq.; Cibrario, Della schiavitù e del servaggio, i. 16.