Carl Menger destroyed two thousand years of economic fallacy with a single insight in 1871: value is subjective, existing only in the mind of the individual valuer. The classical economists—from Adam Smith to David Ricardo—had spent centuries chasing their tails, convinced that value somehow resided in objects themselves, whether through labor content or production costs. Menger obliterated this nonsense by pointing out the obvious: a glass of water means nothing to a man by a river but everything to one dying of thirst in the desert. This breakthrough wasn't just academic—it was revolutionary. By grounding value in human choice and...