So often it is heard that the public good is obtained when men look after their own interests. While there might be some degree of truth in the idea, the real change was one of focus. The modern view shifted the whole perception of the public good. It is no longer an end but merely an effect of another end. Under such a vision, the public good is no longer to be sought but merely engineered as a side concern.
This can be seen in the case of greed. For centuries, the Church had warned against this vice for the harm that it does to the public good since it throws society and economy out of balance.
During the eighteenth century, this concept of greed was sidelined and replaced with the belief that greed promoted economic production. In addition to this revised view of greed, there was the advance of utilitarianism which proclaimed that anything that helped production and progress was good and just. There were no fixed standards of right and wrong but only that which worked and that which did not.
“So comprehensive has been the triumph of this twin revolution,” writes Edward Skidelsky, “that sophisticated minds today find it hard not only to see the love of money as a vice, but to see how anything like the love of money ever could have been regarded as a vice.”
(Edward Skidelsky, “The Emancipation of Avarice,” Samuel Gregg and Harold James eds., Natural Law, Economics, and the Common Good, Imprint Academic, Charlottesville, Va., 2012, p. 155)