Les Australiens featured regularly in the discussions of the Société d'Anthropologie. Its members were interested in where the Aborigines had come from or whether they were autochthonous, in their 'civilization' (what would now be called 'culture'), and, given its perceived paucity, their presumed closeness to nature. More precisely, information about Aborigines was seized upon as ammunition in two debates. The first hinged on the question of whether or not there was a distinct règne humaine, 'human kingdom', set apart from the animal world. In the nineteenth century, advances in various branches of scientific knowledge that impinged on human origins — archaeology, geology, biology, linguistics — and the burgeoning information about indigenous people around the world gave particular urgency to the age-old question of what it is to be human. Debates recorded in the Bulletins and Mémoires reveal the passionate interest in this question. A variety of non-European groups which were judged to be inferior, frequently Australians and Tasmanians, was routinely invoked as a test case of either humanity or bestiality.

The second and related issue which drew on Aboriginal evidence was that of monogeny versus polygeny, the common or multiple origins of the 'races of man'. Monogenists saw humankind as ultimately one, the descendants of a single pair of human ancestors; polygenists posited that different racial groups had separate and different origins. The monogenist position was conservative, its adherents likely to be Christian believers who rejected as heretical the proposition that there had been human beings other than the first divinely created pair. Polygenists were able to conceive a non-Biblical view of human origins and were prepared to countenance the unsettling of scriptural teaching and hence religious institutional authority. The intellectual and political radicalism of the racialist polygenists is disconcerting to liberal-minded modern scholars but for these scientists of the Third Republic, political progressiveness was consonant with the intellectual assumption of significant hereditary differences between human groups.^[16] The racial rhetoric of both monogenists and polygenists is abhorrent to present sensibilities but that used by polygenists to discuss human difference and supposedly inferior forms of humanity is especially noxious.

It is beyond the scope of this chapter to examine the ways in which doctrines such as polygeny and the supposed likely extinction of inferior races, much discussed by members of the Société,^[17] related to accelerated French colonial expansion in the second half of the nineteenth century. Material about Aborigines was only indirectly relevant to French colonialism per se but was nonetheless pertinent comparatively to the process of imposition of French colonial rule over indigenous populations.