This is a quote from the book "The ​Virtue Of Selfishness" by Ayn Rand
...ctive gang of citizens who would fight other gangs, formed for the same purpose, and thus bring about the degeneration of that society into the chaos of gang-rule, i.e., rule by brute force, int o perpetual tribal warfare of prehistorical savages.

The use of physical force — even its retaliatory use — cannot be left at the discretion of individual citizens. Peaceful co
existence is impossible if a man has to live under the constant threat of force to be unleashed against him by any of his neighbors at any moment. Whether his neighbors’ intentions are good or...
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