Written against the backdrop of the Communist seizure of power in the Soviet Union, this remarkable work by America's leading early twentieth century racial theorist studies the root causes of Communism and the destruction of civilized society. It focuses on the downbreeding of existing European populations and of how the worst elements of society are continually outbreeding the best, leading to lower average IQs and civilizational levels. Although directed at Soviet-era communism, the reader will find the discussions on racial and social degeneration appallingly familiar and present in twenty-first century Western societies. Finally, a solution to the problem is proposed: not repression, but eugenics. "Where but in the slender ranks of the racially superior-those 'A' and 'B' stocks which, in America for example, we know to-day constitute barely 13 1/2 per cent of the population? It is this "thin red line" of rich, untainted blood which stands between us and barbarism or chaos."