Charles Darwin's influential 1859 book On the Origin of Species did not discuss human origins. The extended wording on the title page, which adds by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, uses the general term "races" as an alternative for "varieties" and does not carry the modern connotation of human races. The first use in the book refers to "the several races, for instance, of the cabbage" and proceeds to a discussion of "the hereditary varieties or races of our domestic animals and plants".[57] In The Descent of Man, and Selection in Relation to Sex (1871), Darwin examined the question of "Arguments in favour of, and opposed to, ranking the so-called races of man as distinct species" and reported no racial distinctions that would indicate that human races are discrete species:
It may be doubted whether any character can be named, which is distinctive of a race and is constant ... they graduate into each other, and ... it is hardly possible to discover clear, distinctive characters between them ... As it is improbable that the numerous, and unimportant, points of resemblance, between the several races of man, in bodily structure and mental faculties (I do not here refer to similar customs) should all have been independently acquired, they must have been inherited from progenitors who had these same characters.[56][58]
In Richard Weikart's 2004 book From Darwin to Hitler: Evolutionary Ethics, Eugenics and Racism in Germany he claims:
Darwin clearly believed that the struggle for existence among humans would result in racial extermination. In Descent of Man he asserted, "At some future period, not very distant as measured by centuries, the civilised races of man will almost certainly exterminate and replace throughout the world the savage races."[59][60][61][62][63]
According to talk.origins, this is a common creationist quote mine.[64] They argue that when Darwin referred to "race" he meant "varieties," not human races,[65] as per the cabbage example cited above. Apart from the plain meaning of the words, they assert "there is nothing in Darwin's words to support (and much in his life to contradict) any claim that Darwin wanted the 'lower' or 'savage races' to be exterminated. He was merely noting what appeared to him to be factual, based in no small part on the evidence of a European binge of imperialism and colonial conquest during his lifetime." [66] The quoted passage, in full context, reads:
The great break in the organic chain between man and his nearest allies, which cannot be bridged over by any extinct or living species, has often been advanced as a grave objection to the belief that man is descended from some lower form; but this objection will not appear of much weight to those who, from general reasons, believe in the general principle of evolution. Breaks often occur in all parts of the series, some being wide, sharp and defined, others less so in various degrees; as between the orang and its nearest allies—between the Tarsius and the other Lemuridae between the elephant, and in a more striking manner between the Ornithorhynchus or Echidna, and all other mammals. But these breaks depend merely on the number of related forms which have become extinct. At some future period, not very distant as measured by centuries, the civilised races of man will almost certainly exterminate, and replace, the savage races throughout the world. At the same time the anthropomorphous apes, as Professor Schaaffhausen has remarked, will no doubt be exterminated. The break between man and his nearest allies will then be wider, for it will intervene between man in a more civilised state, as we may hope, even than the Caucasian, and some ape as low as a baboon, instead of as now between the ***** or Australian and the gorilla.
— The Descent of Man (1871), Volume I, Chapter VI: "On the Affinities and Genealogy of Man", pages 200–201
In the Chapter "On the Development of the Intellectual and Moral Faculties during Primeval and Civilised Times" Darwin claimed that "the western nations of Europe, who now so immeasurably surpass their former savage progenitors, and stand at the summit of civilisation, owe little or none of their superiority to direct inheritance from the old Greeks"[67]
While proposing a sole human species, Darwin contrasted the "civilized races" with the "savage races". Like most of his contemporaries, except the naturalist Alfred Russel Wallace, he did not distinguish "biological race" from "cultural race". Moreover, he noted that savage races risked extinction more from white European colonialism, than from evolutionary inadequacy.[56][68]
On the question of differences between races, Darwin wrote:
There is, however, no doubt that the various races, when carefully compared and measured, differ much from each other,—as in the texture of the hair, the relative proportions of all parts of the body, the capacity of the lungs, the form and capacity of the skull, and even in the convolutions of the brain. But it would be an endless task to specify the numerous points of structural difference. The races differ also in constitution, in acclimatisation, and in liability to certain diseases. Their mental characteristics are likewise very distinct; chiefly as it would appear in their emotional, but partly in their intellectual, faculties. Every one who has had the opportunity of comparison, must have been struck with the contrast between the taciturn, even morose, aborigines of S. America and the light-hearted, talkative negroes. There is a nearly similar contrast between the Malays and the Papuans, who live under the same physical conditions, and are separated from each other only by a narrow space of sea.[69]