Cover of The Pure SocietyWhat do the Catholic Church, Anglo-Saxon liberalism and Russian Lysenkoism (the doctrine of acquired characteristics) have in common? The correct answer, one might hope, is that they have all been intellectually discredited. Unfortunately, as André Pichot's book makes clear, the answer is also that they were the only significant sources of opposition to eugenics in the period of its heyday between 1907 and 1945. It is hardly a testament to human reason that opposition came from a church keen to keep its monopoly on body and soul, hardcore liberals who were against eugenics as an example of state interference but often happy to let "nature" (or the market) remove the "unfit", and bad science that contributed to the disastrous record of Soviet agriculture. Eugenics, argues Pichot, was not the work of a few cranks and Nazi ideologists, it was the mainstream and its opponents were the intellectual "eccentrics".

Eugenics attracted some unexpected adherents, among them Julian Huxley - biologist, social democrat, director of UNESCO and, of course, one of the founders and first president of the British Humanist Association. In 1941, when the Nazis were gassing the mentally ill in the name of racial purity, Huxley argued that eugenics would be part of "the religion of the future" (the phrase is a quote from the father of eugenics, Francis Galton). In the same work Huxley also suggested that black people were probably of slightly lower than average intelligence compared to white or yellow people. (Pichot is not trying to discredit Huxley in particular, but rather establishing how widespread eugenics remained across the political spectrum and how it persisted even after the Nazi defeat.)

In this catalogue of repulsive opinion a few moments of inadvertent black comedy stand out. One of these is the proposal made by the French eugenicist Vacher de Lapouge in 1896 that the solution to "degeneration" would be to send those he regarded as degenerates and perverts to special settlements where they would be encouraged to indulge their vices to the full, thereby leading to an early demise. (Lapouge notes how the availability of low-priced alcohol was very effective in destroying the indigenous peoples of Oceania and the Americas.)

Pichot controversially suggests that the taboo on recognising the widespread belief in eugenics has served to minimise and disguise the links between contemporary biology and eugenic and racist themes. Biology has a recurrent tendency to make such incursions into social policy. Darwin's own models of struggle, selection and cooperation, borrowed heavily from the existing sociological models of his time - notably Malthus, Adam Smith and Hobbes - and once these models had been biologised by Darwin they were easily exported back into the social sciences. Pichot suggests that whenever genetics runs into scientific problems it becomes more strident concerning its sociological and political claims.

In a bracing passage Pichot singles out Richard Dawkins and his thesis of the "selfish gene" - in which human beings are reduced to being mere carriers of a genetic inheritance. He argues that this "genetic mysticism" echoes the promotion by Nazi biological thinking of the priority of the racial community over the individual. Although suggestive, and useful in indicating the dubious political implications of Dawkins's genetic reductionism, the argument comes close to guilt by association, and more teasing out of this claimed continuity is necessary to make the charges stick.

In light of the current celebration of the 150th anniversary of the publication of Darwin's Origin of the Species, Pichot's work is a salutary warning. As he notes, the malignant ideologies of eugenics have not disappeared, but are now privatised with the pressure of the market, the media and medicine encouraging us to breed our own "perfect" offspring. The key question The Pure Society poses is how we can defend human beings against being reduced to mere raw material, or animals fit for breeding, without relying on the usual religious models of the sacred inviolability of human life. Although science has served humanists as a powerful model of critique of religious ideology, we must also be careful to avoid the deification of science. After all, science itself is in no way immune to ideology and the humanist should be wary of any self-proclaimed "religion of the future".

The Pure Society is published by Verso