As Geddie and Inglis were establishing the Aneityum mission, the German scholar and linguist Friedrich Max Müller, who remained a committed Lutheran despite the theological and scientific debates that raged around him, was settling into Oxford as professor of modern languages and later comparative philology (Chaudhuri 1974:69). Over the next thirty years, Müller was to prove an important advocate for human congruity, particularly on the issues of faith and intellect. Profoundly influenced by the German philosopher Friedrich Schelling (1775-1854), Müller developed an essentially evolutionist theory that 'myth' was the product of an 'indwelling law' through which religious belief was expressed. Thus, Christianity was inherent in all faiths as it found expression in different phases along the path to the godhead (Trompf 1969:202). While believed by many to be profoundly Darwinian, Müller refused to admit the mechanism of natural selection in relation to the development of language and held that the capacity for speech constituted the demarcation point between human beings and animals. In 1873, he delivered a series of lectures on this point against Darwin's theory (Müller 1873). Darwin, acknowledging Müller's intellect and standing, pronounced him a 'dangerous man' and wrote that being criticized by him made him feel 'like the man in the story who boasted he had been soundly horsewhipped by a Duke' (Chaudhuri 1974:258). Müller was a friend and correspondent of a number of missionaries in the field, including the Bishop to the Melanesian Mission John Coleridge Patteson (1827-1871), his colleague Robert Codrington (1830-1922), and the Methodist Lorimer Fison (1832-1907).^[16]

For some clergy and missionaries, the debate about religious sensibility was formulated on the idea of degeneration: the belief that, after the deluge and the dispersal of the tribes, some had wandered so far across the world and been separated from God for so long that they had lost the ability to think in religious terms. For others, less concerned with Biblical literalism, 'degeneration' was merely the loss of the conscious knowledge of God: indigenous beliefs, while misguided, were proof of an inherent spiritual capacity which indicated their place in the family of God. Still others professed, along with Müller, a form of evolutionism in which races gradually passed through stages of religious belief led by the indwelling Spirit towards the pinnacle of Christian knowledge.

The text from the Australian colonies that was to prove most influential in British debates in the 1860s and 1870s on the religious sensibility of Aborigines was Queensland, Australia (1861) by Reverend John Dunmore Lang (1799-1878). The book was primarily intended as an invitation to immigrants but also includes a long essay on Queensland Aborigines based on Lang's attempt in 1837 to establish a mission at Nundah, Queensland, which was abandoned in 1843. As a result of this failure, Lang was dubious about the intellectual or religious ability of Aborigines (Bridges 1993:12). While Lang's numerous publications ensured his reputation in Britain, in the Australian colonies his relationships were so rancorous that he defended a number of libel charges over the course of his career, including one from Threlkeld whom he sought to have dismissed.^[17] In Queensland, Australia, Lang focused his well-honed scorn on a successful publication by Paul Edmund de Strzelecki (1797-1873), Physical Description of New South Wales and Van Diemen's Land (1845). In this account, Strzelecki (1845:339) claimed that indigenous Australian 'recognise a God, though they never name him in their vernacular language, but call him, in English, "Great Master," and consider themselves his slaves…. They believe in an immortality, or after-existence, of everlasting enjoyment, and place its locality in the stars, or other constellations'.^[18] Lang's response to Strzelecki showed the minister's theological opposition to the notion of a universal religious sensibility and probably harked back to his opposition to Threlkeld. 'I have always been very sceptical in regard to the ideas alleged by certain travellers to be entertained by barbarous tribes on the subject of God', wrote Lang (1861:375‑6). He acknowledged that it was against the 'preconceived ideas, or the philosophical system, of certain writers, to admit that there is any portion of the human race living entirely without a religion' and yet missionaries reported such evidence not only amongst the 'Papuan aborigines of Australia' but also in the fledgling congregations of Greenland and Southern Africa.

In the second half of the nineteenth century, religious belief, or the lack thereof, became fertile ground for the discussion of the relationship between human beings and animals. Lang's testimony became evidence for both sides of an unexpected alliance between, on the one hand, clergy or religious people who believed in degeneration and were horrified by the suggestion that heathen beliefs shared anything with the Christian promise of salvation; and, on the other hand, scientists who were keen to minimize the distinction between some human beings and animals in order to strengthen evolutionary arguments about the ultimate origin of mankind within the animal kingdom or to prove that human races were the outcome of multiple origins. In a short address to the Anthropological Society of London in 1864 on the 'Universality of Belief in God, and in a Future State', the Archdeacon of Westminister, the Very Reverend Frederic W. Farrar (1831-1903), who was later chaplain to Queen Victoria, quoted Lang, amongst others from around the world, to claim (1864a:ccxvii): 'there are not only isolated tribes, but whole nations who are so degraded as to live with no knowledge of their Creator'. For Farrar (1864a:ccxviii), the revelation of Christ and the Judeao-Christian God had no parallel with the spirits of 'savages' whose religious beliefs could be compared to the involuntary reactions of animals: 'a vague fear of the Unknown is found even among animals, and is widely different from a belief in God'. The assembled members then debated the paper and revealed a range of possible positions on the issue. Alfred Russel Wallace (1823-1913) described the absence of belief amongst the 'wild tribes of Molucca and of New Guinea' with whom he was familiar. A Reverend Kerr commented that in his parish work in Liverpool he had found many who had 'but little notion of a God'. Another insisted that he had never met an African Negro who did not believe in the existence of a good or bad spirit. The president of the Anthropological Society, James Hunt (1833-1869), a professed polygenist, believed that Farrar's evidence against the general assumption of universal belief was of particular importance to anthropology. For his part, Farrar held that he was merely confirming the Biblical claim that 'there were people who knew not God' (1864a:ccxix-ccxxi). However, his second paper, 'On Hybridity' (1864b), which was then read to the members, was based on a scientific argument about interracial infertility that revealed he had a close knowledge of polygenist theories on the failings of the human 'hybrid' and his analysis implied separate human origins.

In the early 1870s, several anthropological texts addressed the question of a universal religious sensibility in relation to the distinction between human beings and animals. In their respective publications The Descent of Man (1871) and The Origin of Civilisation (1870), Darwin and Lubbock implied that the absence of religious belief amongst some human groups could be likened to a psychic missing link that was evidence for the maturation of human beings from apes.^[19] Opposing them, from a different intellectual tradition, were Tylor, who published Primitive Culture in 1871, and Müller, whose Introduction to the Science of Religion (1873) argued for a universal and innate religious sensibility in all human groups.^[20]

In The Origin of Civilisation, Lubbock (1870:212) stated that the 'evidence of numerous trustworthy observers' opposed the belief that 'religion is general and universal'. Lang was held to be a particularly trustworthy observer as his findings were believed to be in opposition to his Christian beliefs. Yet here Lubbock was either ignorant of Lang's degenerationism or misrepresented him. Degenerationism as professed by Lang meant the loss of the knowledge of God to the point where a religious sensibility was completely absent. Lang (1861:377) held that 'Papuan' ignorance of the 'knowledge of God' was to be expected for 'almost every trace of divine knowledge … [had] disappeared at a comparatively early period in the history of the postdiluvian world, among all the other Gentile nations'. This position was distinct from evolutionist theories such as Lubbock's which claimed that the gradual development of man from ape could be mapped on to existing populations using evidence such as religious sensibility. Without acknowledging Lang's degenerationism, Lubbock (1870:212) simply used his work as evidence for his own implicit claim of the essential similarity between the 'lowest races' and animals: 'we must admit that the feeling of a dog or a horse towards its master is of the same character; and the baying of a dog to the moon is as much an act of worship as some ceremonies which have been so described by travellers'.^[21]

Lubbock's friend and mentor Darwin published The Descent of Man the following year. In a chapter comparing the 'Mental Powers of Man and the Lower Animals', Darwin (1871, I:53-62) responded to those who insisted that the gulf between human beings and animals could not be bridged by his theory. 'Instincts' shared with animals, such as maternal affection, curiosity, imitation, attention, were the primary foci of the chapter but he also included discussion on language with an oblique attack on Müller. The chapter finishes with a sub-section on 'Belief in God — Religion' (1871, I:65-9). In an attack on Tylor's explicit claim for a universal religious sensibility and his implicit argument that this was a primary division between human beings and animals (Tylor 1866:71-81; 1870:370), Darwin insisted:

Darwin (1871, I:65-7) did allow that amongst 'the less civilised races' there was a universal belief in 'spiritual agencies' but held that this did not mark the divide between human beings and animals because a similar belief could be found in his dog, a 'very sensible animal' who growled at the movement of a parasol in the wind, attributing it to some 'strange living agent'.

In his conclusions, Darwin (1871, II:394-5) acknowledged the importance of the debate over an innate religious sensibility to his theory of the development of human beings from animals: 'The belief in God has often been advanced as not only the greatest, but the most complete of all the distinctions between man and the lower animals'. He even provided a salve to religious sensitivities concerned about the point of human development where man developed an immortal soul and he stopped short of the explicit suggestion that 'primitive man' was not part of the family of God. Ultimately, however, Darwin insisted that it is 'impossible to maintain that this belief [in God] is innate or instinctive in man'.

E.B. Tylor's Primitive Culture, also published in 1871, is primarily a work on religion. The anthropologist Adam Kuper (1988:77) argued that during this early period of anthropology there was a shift from questions of political development to the relationship between belief and rationality. Thirteen of Tylor's twenty chapters in the two-volume work are concerned with rites, rituals, mythology, and animism. The chapters on animism begin with the question posed in his two earlier articles on religion: 'Are there, or have there been human tribes so low in culture as to have no religious conceptions whatever?'^[22] While Tylor insisted that the question had been asked over centuries, in this instance it was clearly formulated against Lubbock and Darwin. The observations of J.D. Lang were immediately in Tylor's firing line. Recognizing the degenerationism in Lang's analysis that Aborigines were without belief in a god, Tylor applied some of Lang's other findings of evil or benign spiritual agents to his own definition of what constituted religious thought, based on his theory of animism. By this criterion, Tylor (1871, I:379) found that Lang's observations were proof that 'the natives of Australia were at their discovery, and have since remained, a race with minds saturated with the most vivid belief in souls, demons, and deities'.

Tylor supported this argument with page after page of careful depositions against similar claims for the absence of religious thought amongst indigenous people. He held that the primary error committed by those who failed to acknowledge a religious sensibility in their observations was the definition of religion as 'the organised and established theology of the higher races' (1871, I:380). The words that follow dramatize the divide between earlier anthropologists such as Prichard, who had been sympathetic to missionaries and uncritically accepted the quality of their accounts, and their more sceptical successors who held that missionary observations were invariably tainted by an overt Christian agenda. Tylor believed that missionaries who acknowledged the pre-Christian beliefs of their congregations were rare and enlightened souls. He claimed, however, that for the most part the '"religious world"' despised heathen beliefs and that missionaries had neither the time nor the capacity to understand them. Kuper convincingly argued that the implication to be drawn from Tylor's theories on religious evolution was that nineteenth-century man was developing beyond belief and theology to the superior knowledge of science. The most progressive vantage point from which to view 'primitive religion', therefore, was that of the scientific observer. According to Tylor, missionary observations were intrinsically tainted, owing to the beliefs of the observer, and belonged to an earlier system of data collection (Kuper 1988:80).

The strongest definition of the role of faith in the unity of humankind came from Müller's series of lectures published in 1873 as Introduction to the Science of Religion. In a thesis that sustained his attack against Darwin's attempt to minimize the human/animal divide, Müller described the religious sensibility as one of the two faculties that defined man as utterly distinct from animal:

As with Prichard, Müller believed that the correlation between faith and human unity was proved by a capacity for religious thought rather than an adherence to a specific religion. His final sentence in the above passage shows the usefulness of developmental theory as a means both to describe and prescribe differences between human groups. As Stocking (1968:73) has shown in relation to Tylor's use of the singular for 'culture' in his famous definition of the term, Müller's reference to the 'lowest worship of idols and fetishes', followed by the use of upper case and singular for 'God', suggests similarly that religious evolutionism described difference as stages along a single defined path toward a Christian end.