Malthusian ideas are enjoying a revival, perhaps unsurprising in an age of ecological crisis. Across the world, food and water supplies are critically threatened by climate breakdown. Thanks to the combined effects of pollution and extractive agribusiness, the soil in Britain has fewer than a hundred harvests left. You don’t have to look hard to find someone arguing that we are breeding ourselves into oblivion. To the fear that there will not be enough food for earth’s people, Malthus prescribes a beguilingly simple solution: reduce the number of people on earth.