Ayn Rand famously summarized her ethics of rational egoism with the proverb “God said: ‘Take what you want, and pay for it.’” The idea here is that if you want the values that will serve your life and happiness (e.g., a fulfilling career, romance, leisure time, recreation) then, by the nature of reality (“God said”), you must enact the necessary causes (“pay for it”). Rand, of course, was an atheist, so her use of “God” here is metaphorical.
It is interesting to note that the basic law governing the field of economics, Say’s Law, is essentially this same principle applied to the marketplace.
Say’s Law—named after the French economist Jean-Baptiste Say—is the recognition of the fact that in order to purchase goods or services in a marketplace, you must first produce value with which to trade. . . .