Adam Smith essentially founded our modern phase of the Western Enlightenment by anchoring a central postulate -- one that Pericles and Locke discussed earlier, and that others, like Hayek, later embellished. The postulate thathuman beings are supreme rationalizers and self-deceivers.
Moreover, across 4,000 years we’ve seen that whenever a small group of men become powerful enough to control an economy and command-allocate its resources, they will do so according to biased perceptions, in-group delusions and fatally limited knowledge. Whether they do the normal oligarchic thing -- cheating for self-interest -- or else sincerely try to “allocate for the good of all,” they will generally do it badly. As a blatant recent example, Robb cites the collapse of the Soviet Union.