The shift in attention from a teleological concern for origins to the measurement and classification of existing groups diminished the practical import of the ideological opposition of monogeny and polygeny, despite the huge rhetorical investment of both sides in the debate. Belief in original human unity coexisted more or less uneasily with perceptions of present diversity in the thinking of several of the savants discussed above, who endorsed the conventional position but with growing equivocation. Cuvier and most of his followers — who included Lawrence as well as several polygenists — evinced little concern for origins.^[72] But they espoused the fixity of species, the inheritance of racial characteristics, the primacy of physical organization, and the diagnostic interconnectedness of cranial structure and intelligence as a key racial differentia.^[73] In a reminder of Lacépède, Cuvier (1812:105-6) posited an ancient — perhaps originary? — differentiation of 'the negroes' as the 'most degraded human race', closest in form to 'the brute', and without the 'intelligence' to achieve regular government or sustained knowledge. All the characters of this race, he asserted, showed 'clearly' that it had 'escaped the great catastrophe at another point from the Caucasic and Altaic [Mongol] races' and had 'perhaps' been separated from them long before it occurred. Cuvier's ambivalence about original human unity mirrored the reservations of the geographer Conrad Malte-Brun (1775-1826) about the 'orthodox doctrine', the 'system of a common human origin', that he would 'neither refute nor confirm'. Balbi was similarly noncommittal with respect to Desmoulins's polygenist 'system'.^[74] It was thus not merely politic for Bory de Saint-Vincent to dedicate his polygenist treatise L'homme to Cuvier, in whose 'footsteps' he claimed to tread, or inappropriate for him to acknowledge Malte-Brun as his precursor 'in distinguishing the species of Men … under the designation of races'. Bory's functional set of specific differentiae and their pessimistic corollaries echoed Cuvier's racial criteria. Human species did 'not derive their differences from colour only' but were distinguished more by 'structure' and aspects of 'internal organization' which influenced 'the intellectual faculties' and determined 'the level of moral development each can reach'.^[75]

Notwithstanding this broad community of racial assumptions, particularly evident in France, polygenists' taxonomies were in general more starkly racialized than those of monogenists because they typically classed some human species close to the apes while quarantining 'civilized man'/'the white man'/'the European' from this debasing association. White's work (1799) is an obvious case in point though that of Desmoulins (1826) is not. Virey (1824, III:460-3) refused absolutely to place 'this king of the globe' alongside 'the orang-outang' because the civilized European 'reigns' over all other beings in the creation, including 'the inferior races of his own species'. Not for him Bory's contemptuous denial of rationality to all but a favoured handful of Japhetic men. In Virey's view, an 'immense distance' separated a 'Hottentot Boschisman' from even a 'simple European peasant'. Therefore, although 'the ape' could not be grouped 'with us', the orangutan genus, in particular, was clearly 'not very far from the least perfect species of men'. Monogenists, in contrast, usually expressed their core premise of human psychic uniqueness by segregating the single human species as the sole genus of a separate order within the animal kingdom.

The number of species identified by polygenists and the degree of disparateness attributed to races by monogenists were key signifiers of the relative acrimony and rigidity of racial discriminations. Multiplication of species widened purported inequalities between groups and heightened scepticism about the improvability of some.^[76] Thus, Bory de Saint-Vincent's hairsplitting taxonomy of numerous human species and his bracketing of the genus Homo with the genus Orang within the family or order of Bimana (see note 64) had invidious implications for certain groups that were not inherent in Cuvier's sweeping division of the human genus into three races isolated as Bimana. The systemic metonymy of Bory's ranking of the 'Hottentot species' as the generic 'passage' from man to orang was potentially more injurious — though no more insulting — than Cuvier's incidental analogy of 'negro' resemblance to 'the apes'. Yet assessing the relative obloquy of racialized language is problematic and perhaps futile since the ideological impact of Bory's entire 'zoological essay' on man was arguably outweighed by the 'veritable raciological synthesis' — Blanckaert's phrase — contained in Cuvier's cursory remarks about human races, made by a highly influential savant who rejected speculative 'system' and laid claim to the 'more solid edifice of facts and of induction'.^[77] Cuvier's position was also paradoxical with respect to the 'minimally polygenist' Virey who posited two human species but represented the final race of his '1st species' — the 'Malay or Polynesic' — as close to the 'negro type', an 'intermediate nuance between the Mongols and the Negroes', and a 'bastard race' linked by 'diverse gradations' to the 'blackish' Papuans.^[78] Such racial indeterminacy was normally an argument for human specific unity but Cuvier's formal adherence to this credo was vitiated by his insistence that races were 'eminently distinct'.

When human variation was judged to be confined within a single species, acknowledgement of the transposability and the internal diversity of races could have the reverse effect to multiplication of species — narrowing rather than widening divergence and attendant inequalities. From this perspective, the greater the perceived intraspecific variation, the stronger the case for a unified human species since apparently different races overlapped or blended and physical differences within races could exceed those between them, points made strongly by Prichard (1826, II:588-9): the 'character of one race passes into that of another' while sometimes 'the most different complexions, and the greatest diversities of figure, known to exist, are to be found among tribes which appear to belong to the same nation, or family of nations'. Contemporary contributors to the polemic on the unity of the human species were aware that 'the fractionating tendency', as Stocking put it (1973:lxxi-lxxii), produced 'monogenetic rather than polygenetic conclusions'. Lawrence (1819:502) maintained pragmatically that 'the very numerous gradations' in human appearance, form, and attributes were 'an almost insuperable objection to the notion of specific difference', since any might be attributed to 'original distinction of species', in which case 'the number of species would be overwhelming'.^[79] Prichard (1826, II:588) insisted that there was 'no clearly traced and definite line which the tendency to variety or deviation cannot pass, and therefore, no specific distinction'. The English naturalist Charles Darwin (1809-1882) witnessed great human variation in the course of HMS Beagle's global surveying voyage of 1831-36. Years later (1871, I:225-6), he distilled that experience into a monogenist precept: 'the most weighty of all the arguments against treating the races of man as distinct species, is that they graduate into each other … and that it is hardly possible to discover clear distinctive characters between them'.

Yet by 1860, Prichardian ethnology and biblical monogeny had lost scientific credibility in Britain and been overshadowed by more naturalistic approaches to the science of man. A mostly polygenist, highly racialist group of Anthropologicals led by Hunt briefly seized the limelight but were in turn eclipsed by the dominant evolutionism of the next decade.^[80] In the face of the growing credibility of polygeny, embattled monogenists normalized racial terminology and logic, as Prichard had steadily done from the 1820s. Lawrence, who had vigorously defended human specific unity in his 1818 lectures, reportedly admitted in 1856 that he was now 'convinced of the diversity of human origin'.^[81] In France, polygenist belief in multiple human species was integral to the heavily anthropometric and craniological anthropologie practised under the leadership of the physician-anatomist Paul Broca (1824-1880), recent founder of the Société d'Anthropologie de Paris (Figure 5). Leading monogenist naturalists of the Muséum national d'Histoire naturelle, such as the comparative anatomist Etienne-Renaud-Augustin Serres (1786-1868), the zoologist Isidore Geoffroy Saint-Hilaire (1805-1861), and the anthropologist Armand de Quatrefages (1810-1892), co-existed uneasily with Broca'a institutional control of anthropologie by combining equivocal belief in original human unity with firm commitment to the scientific worth of craniometry and acceptance of the irreversibility, permanence, and inequality of races, regarded as biological types.^[82]

In 1841, Serres had endorsed a significant gesture toward polygeny in presenting a special report of a commission of the Académie des Sciences on the anthropological collections made by the phrenologist Pierre-Marie Alexandre Dumoutier (1797-1871) during the recent global circumnavigation of Jules-Sébastien-César Dumont d'Urville (1790-1842). With respect to the contentious issue of the unity or plurality of human types, the report argues for a 'double character': the human species was 'unique' with respect to generation but definitely plural with respect to 'the hereditary transmission of characters'. By conceding that Aboriginal Australians might 'at a pinch' be seen as autochthonous, the commission left open the possibility of a separate origin for this allegedly 'most inferior' of Oceanian races. The members agreed with Dumont d'Urville (1832:15-16) that the 'black race' was the 'mother stock' of the 'primitive inhabitants' of the region who had been displaced by successive 'invasions' of 'more advanced' races. The supposed displacement process climaxed in the onset of vastly 'superior' European civilization and imminent racial 'fusion'. The report thus implies a teleological trajectory from a single human creation, to the very ancient differentiation of 'three primordial types', culminating in the prospect of ultimately renewed unity through colonialism and asymmetric racial crossing. Since the final stage was still 'in full swing' in Oceania, the region exemplified the realization in practice of the universal scheme. Throughout the report, a compromised monogenism jostles with profound ambivalence about the 'black race' and a smug conviction that the European race 'dominates all the others by the superiority of its physical and moral characters'.^[83]

Figure 5: [Alphonse] Vien, 'Le craniographe de M. Broca'.^[84]

Engraving. Photograph B. Douglas.

Two decades later, in a paper published posthumously, Geoffroy rejected Cuvier's authoritative ternary division of the human genus on the basis of skin colour but followed him by defining races as characteristic 'modifications of the species' and stressing 'constancy' in their 'hereditary transmission'. His threefold criteria for anthropological taxonomy show significant accommodations of polygenist and racialist thinking: the multiplicity of human races; their 'unequal' anatomical, physiological, and psychological value; and the importance of traits derived from the conformation of the head. Accordingly, he increased the number of races to twelve and nominated four as 'principal types' — the 'cardinal points of anthropology' — by adding 'the Hottentot type' to Cuvier's standard racial trinity of Caucasic, Mongolic, and Ethiopic.^[85] Geoffroy's classification 'diametrically opposed' two of these types: the Caucasic — racially glorified as 'the most beautiful' with the 'highest intellectual faculties'; and the Hottentot — racially vilified as the 'inferior' and 'last term in the anthropological series', a branch so 'profoundly separated from the common trunk' as to compromise the 'tradition' of the 'original unity' of the human genus.^[86] These unsubstantiated assertions of 'relative superiority or inferiority' depended scientifically on the hoary Cuvierian measure of the cranio-facial ratio: the theory that the greater the development of the 'superior parts' (the skull and the brain), the higher the race; and that the greater the development of the 'inferior parts' (the sense organs and the jaws), the lower the race. The Caucasic had 'maximum cranial development' and was therefore 'superior'; the Hottentot had 'maximum facial development' and was therefore 'inferior'.^[87]