We may be through with the past, but the past is not through with us. Ideas of the Stone Age exist side by side with the latest scientific thought. Only a fraction of mankind has emerged from the Dark Ages, and in the most lucid brains, as Logan Pearsall Smith has said, we come upon nests of woolly caterpillars. Seemingly sane men entrust their wealth to stargazers and their health to witch doctors. Giant planes throb through the stratosphere, but half their passengers are wearing magic amulets and are protected from harm by voodoo incantations. Hotels boast of express elevators and a telephone in every room, but omit thirteen from all floor and room numbers lest their guests be ill at ease.