Not long ago, Malthusian thinking was revived with a vengeance. In 1967 William and Paul Paddock wrote Famine 1975!, and in 1968 the biologist Paul R. Ehrlich wrote The Population Bomb, in which he proclaimed that “the battle to feed all of humanity is over” and predicted that by the 1980s sixty-five million Americans and four billion other people would starve to death.