Many people today think of eugenics as some abomination invented by the Nazis. Sadly, that is not so. Like anti-Semitism, it was once rampant across the political spectrum. Indeed, as this splendidly comprehensive history makes clear, it was a dominant discourse for most of the first half of the twentieth century. In their introduction, the editors say it was, at the time, regarded as the height of modernism. While it was tarnished, in particular, by the post-war Nuremberg trials, it lingered on, and has a heritage that persists today.

Eugenics sought to be the science of humanity in the machine age. It combined the discoveries of Charles Darwin with Victorian notions of rationalising and industrialising every aspect of society, including humans themselves. Darwin’s half-cousin, the scientific polymath Francis Galton, articulated its basic nostrums best. Natural selection would be replaced by planned selection. ‘That which nature does blindly, slowly and ruthlessly, man may do providently, quickly and kindly… Humanity shall be represented by the fittest races,’ he said.

Eugenics was about rigorously grading humans – dividing the fit from the unfit, the geniuses from the ‘feebleminded’ – a favourite term. Like the breeders of horses, eugenicists were keen to promote reproduction among families of high pedigree. But their creed was about fear as well as hope. Its intellectual underpinnings included Malthusian concerns about rising human numbers, and the related concern that, as modern forms of contraception grew in popularity, the middle classes and white races would be swamped by over-breeding others.

Eugenics’ policy manifestations took many forms. Benignly perhaps, couples were widely recommended to seek physical and mental screening before marriage, to ensure they were fit partners. But they were, in practice, mostly about incarcerating, sterilising, and even euthanasing those considered unfit to reproduce. The Nazis sterilised half a million people in the name of eugenics, even before they embarked on the Holocaust. But such policies were pursued in many countries, and over many decades, to improve the national genetic stock. US eugenicists in the 1930s complained that ‘the Germans are beating us at our own game’.

In the Third Reich, the prime targets for sterilisation and euthanasia were disabled or feeble-minded Germans, rather than foreigners, and, as the editors note, ‘for Australian lawmakers, it was the English insane who were to be excluded’. But racial aspects of eugenics were always prominent. They helped justify policies a century ago to keep southern and eastern Europeans out of the US, and later bolstered the case for apartheid in South Africa.

Yet many on the left also embraced eugenics. For them it was about improving the lot of the poor, by extending ideas about public health to cover racial and genetic hygiene. In Sweden, the cheerleaders for eugenics were the founders of the welfare state, Alva and Gunnar Myrdal. In Britain, the Fabians, too, were keen.

Eugenics has also helped foster some of the key intellectual and social trends that emerged in the late twentieth century. Most of the people who were sterilised by the eugenics movement were women, yet many early feminists embraced the cause. The celebrated American family planning pioneer Margaret Sanger once articulated her credo by saying: ‘More children from the fit, less from the unfit – that is the chief issue of birth control.’ She put one of the US’s most forthright male eugenicists, Lothrop Stoddard, in charge of her American Birth Control League.

Likewise, eugenics helped found the Green movement. Ideas about racial purity chimed with those about ecological protection. The early US environmentalist Madison Grant called for selective sterilisation of ‘the criminal, the diseased, and the insane, extending gradually to weaklings and perhaps ultimately to worthless race types.’ Julian Huxley, the first director of UNESCO and a founder of the World Wildlife Fund, was an avowed eugenicist, even after the Second World War. Eugenics was necessary to ensure that the world was not taken over by ‘the descendents of the least intelligent persons now living,’ he said. Garrett Hardin, inventor of the influential environmental idea of the tragedy of the commons, was also a eugenicist all his life.

Not everyone was smitten. In 1922, G.K. Chesterton published an assault on the movement called Eugenics and Other Evils. H.G. Wells, like many other intellectuals, joined Britain’s Eugenics Society, but appears to have been something of a sceptic. He noted waspishly that the criminals that Galton wanted to sterilise were often ‘the brightest and boldest members of families living under impossible conditions’.

Where have all the eugenicists gone?Did their thinking really die? We hear eugenics surely in the language of ethnic cleansing, and perhaps too in the recent rhetoric about the deserving and undeserving poor. The editors of this volume see the imprint in the Human Genome Project and the ‘democratic eugenics’ of choice about reproductive decisions. Eugenics may be dead as a social and intellectual movement, but the ethical issues it raised have certainly not gone away.