The moral justification of capitalism does not lie in the altruist claim that it represents the best way to achieve 'the common good.' It is true that capitalism does -- if that catch-phrase has any meaning -- but this is merely a secondary consequence. The moral justification for capitalism lies in the fact that it is the only system consonant with man's rational nature, that it protects man's survival qua man, and that its ruling principle is: justice
Ayn Rand (1988). “The Ayn Rand Lexicon: Objectivism from A to Z”, p.78, Penguin