We are not assuming, however, that all human societies have passed through the totemistic and exogamous stages. TOTEMISM AND EXOGAMY But what was the original unit, the totem group, or other division outside of which alone could marriages be arranged? And why was the totem name the limit? Returning to Mr. Donald McLennan’s account of the opinions which his brother did not live to set forth, Totemism arose ‘in a state of man in which no idea of incest existed.’ On this theory, I presume, there would be totem groups before exogamy arose; before it was reckoned ‘incest’ to many within the totem name. This, as we shall see, appears to be sometimes the opinion of the best Australian authorities, Messrs. Fison and Howitt, and Messrs. Spencer and Gillen. It is also the theory of Arunta tradition. The totem belief, as it now exists, imposes many tabus: you may not (as a rule) kill, eat, or use the plant or animal which is your totem; still less perhaps, in the long run, may you ‘use,’ sexually, a woman of your totem. If _this_, or a kindred totem tabu, is the origin of exogamy, then to exogamy (as a law, though not necessarily as a tendency) the totem is prior in time. But I have no reason to suppose that Mr. McLennan ever regarded the totem tabu as the origin of exogamy. In his published works he offers another theory, not commonly accepted. But the important thing to note is that exogamy may conceivably (contrary to Mr. McLennan’s opinion, but in accordance with that of Mr. Atkinson) have existed, or rather tended to exist, before totems arose; much more, then, previous to the evolution of totem names, of totem tabu, and of the idea of incest, _as a sin_, or mystic misdeed, and as an offence to the totem--a religious offence to God, or to ancestral spirits. Persons may have been forbidden to marry within their local group, their ‘fire circle’ before that group had a totem, or a totem name, and they may have been forbidden for reasons purely secular, to which the totem later lent a sanction, and a definite limit. Thus Mr. Tylor, our most sagacious guide in all such problems, writes ‘Exogamy can and does exist without Totemism, and for all we know was originally independent of it.’[28]