Why do great empires and civilizations rise to power and glory, only to decay and disappear? In the nineteenth century, the French diplomat Joseph-Arthur de Gobineau (1816–1882) thought he had found a simple but compelling answer to this question: race. In his Essay on the Inequality of Human Races (1853–1855), from which the following selection is taken, Gobineau argued that the mingling of races has always led, and must continue to lead, to the downfall of great civilizations.