required of him as a compensation should be equivalent to the loss for which he compensates, anything beyond equivalence being regarded as undeserved suffering. If this explanation is correct, the rule of equivalence must originally have been restricted to offences within the social group; for, according to early custom and law, only members of the same society have equal rights. In speaking of the tit-for-tat system prevalent among the Guiana Indians, Sir E. F. Im Thurn expressly says, "Of course all this refers chiefly to the mutual relations of members of the same tribe."[82] And when we find savages acting according to the same principle in their relations to other tribes, the reason for this may be sought partly in the strong hold which that principle has taken of their minds, and partly in the dangers accompanying intertribal revenge, {180} which make it desirable to restrict it within reasonable limits. [Footnote 75: Krause, _Tlinkit-Indianer_, p. 245 _sq._ Macfie, _Vancouver Island and British Columbia_, p. 470. Foreman, _Philippine Islands_, p. 213 (Negrito and Igorrote tribes in the province of La Isabela). Low, _Sarawak_, p. 212 (Dyaks). von Langsdorf, _Voyages and Travels_, i. 132 (Nukahivans).] [Footnote 76: Jagor, _Travels in the Philippines_, p. 213 (Igorrotes). Blumentritt, quoted by Spencer, _Principles of Ethics_, i. 370 _sq._ (Quianganes of Luzon). Munzinger, _Ostafrikanische Studien_, p. 243 (Marea). _Koran_, ii. 173.] [Footnote 77: von Martius, _op. cit._ i. 129 (Brazilian Indians). Wallace, _Travels on the Amazon_, p. 499 (Uaupés). Schoolcraft, _Indian Tribes of the United States_, iii. 246 (Dacotahs). Steller, _Kamtschatka_, p. 355; Hickson, _A Naturalist in North Celebes_, p. 198 (Sangirese of Manganitu). Fraser, _Journal of a Tour through Part of the Him[=a]l[=a] Mountains_, p. 339 (Butias). Ellis, _History of Madagascar_, i. 371. Munzinger, _op. cit._ p. 502 (Barea and Kunáma). de Abreu, _Canary Islands_, p. 27 (aborigines of Ferro).] [Footnote 78: Im Thurn, _op. cit._ p. 213 _sq._ (Guiana Indians). _Glimpses of the Eastern Archipelago_, p. 86 (Bataks). Arbousset and Daumas, _Tour to the North-East of the Colony of Good Hope_, p. 67 (Mantetis). Munzinger, _op. cit._ p. 502 (Barea and Kunáma). Post, _Afrikanische Jurisprudenz_, p. 27 (various other African peoples), de Abreu, _op. cit._ p. 71 (aborigines, of Gran Canaria).] [Footnote 79: _Cf._ Tissot, _Le droit pénal_, i. 226; Steinmetz, _Ethnol. Studien zur ersten Entwicklung der Strafe_, i. 401; Makarewicz, _op. cit._ p. 13.] [Footnote 80: von Martius, _op. cit._ i. 128 (Brazilian aborigines). Calder, in _Jour. Anthr. Inst._ iii. 21 (Tasmanians). Forbes, _A Naturalist's Wanderings in the Eastern Archipelago_, p. 473 (Timorese). Sarasin, _Forschungen auf Ceylon_, iii. 539 (Veddahs). Jacob, _Das Leben der vorislâmischen Beduinen_, p. 144 _sq._] [Footnote 81: Browne, _Christian Morals_, iii. 12, p. 94.] [Footnote 82: Im Thurn, _op. cit._ p. 214.]