Error, like truth, flourishes in crowds. At the heart of sympathy each finds a home... No form of contagion is so insidious in its outset, so difficult to check in its advance, so certain to leave germs that may at any moment reveal their pernicious power, as a mental contagion–the contagion of fear, of panic, of fanaticism, of lawlessness, of superstition, of error....In
