On Ethics, Revisited Yet Again

As it turns out, social morality is not the only field in which each person cannot be left merely to look out for themselves and an overarching intervention for the common good is necessitated;  economics also discovered that implication of human nature.  As Keynes wrote,

It is not true that individual possess a prescriptive "natural liberty" in their economic activities.  There is no "compact" conferring perpetual rights on those who have or on those who acquire.  The world is not so governed from above that private and social interest always coincide. It is not so managed here below that in practice they coincide.  It is not a correct deduction from the principles of Economics that enlightened self-interest always operates in the public interest.  Nor is it true that self-interest generally is enlightened.  More often individuals acting separately to promote their own ends are too ignorant or too weak to attain even these.  Experience does not show that individuals, when they make up a social unit, are always less clear sighted than when they act separately.

J. M. Keynes, apud Nicholas Wapshott, Keynes Hayek, p. 35.