… is from Alexis de Tocqueville’s Democracy in America, as quoted on pages 5-6 of George Stigler‘s 1950 book Five Lectures on Economic Problems“:
The principle of self-interest rightly understood produces no great acts of self-sacrifice, but it suggests daily small acts of self-denial. By itself it cannot suffice to make a man virtuous; but it disciplines a number of persons in habits of regularity, temperance, moderation, foresight, self-command; and if it does not lead men straight to virtue by the will, it gradually draws them in that direction by their habits. If the principle of self-interest rightly understood were to sway the whole moral world, extraordinary virtues would doubtless be more rare, but I think that gross depravity would also be less common. The principle of interest rightly understood perhaps prevents men from rising far above the level of mankind, but a great number of other men, who were falling far below it, are caught and restrained by it. Observe some few individuals, they are lowered by it; survey mankind, they are raised.
DBx: Yes, although a background assumption here is that no one has the right to violate the equal property and contract rights of others. The self-interest of someone operating in a market incites that person to behave prudently if not necessarily magnanimously. In contrast, the self-interest of someone operating politically – of a person operating in a setting in which the negative consequences of his or her actions are borne largely by other people with the benefits concentrated mostly on him or her – encourages that person to become a monster.