John Parrish, Paradoxes of Political Ethics, New York, Cambridge University Press, 2007.
But because of the invisible hand, [Adam] Smith thinks, even in the absence of such 'generous and disinterested motives' among society's members, society will nevertheless persist, if somewhat 'less happy and agreeable' than it might have been. In such a case, cooperation will subsist, not as it would among friends, but rather as it might among merchants, 'from a sense of its utility, without any mutual love and affection; and though no man in it should owe any obligation or be bound in gratitude to any other.' The advantage of this more reliable and efficient style of providence is that it does not require widespread virtue: indeed, it really asks for nothing more from human beings than what Smith unsentimentally describes as a 'mercenary exchange of good offices.' Under the division of labor human beings in society have become profoundly interdependent, needing one another's help, vulnerable to one another's harm. Thus it is from this quality of mutual interdependence that both the division of labor and its necessary consequence, inequality (both of station and of talent), arise. [Wealth of Nations, I.ii.4]
Interdependence both motivates and reinforces the market system's reliance on such non-virtuous (though not, on Smith's moral psychology, necessarily vicious) micro-economic motives as self-interest and need. In civilized society, Smith observes, a given human being 'stands at all times in need of the co-operation and assistance of great multitudes, while his whole life is scarce sufficient to gain the friendship of a few persons.' [Wealth of Nations, I.ii.2] Thus if the invisible hand is to perform the providential function that Smith has implicitly assigned to it, it is necessary for it to rely on these less than fully virtuous motives to aid in its work. No longer is scarcity the central concern of economic thinking, though of course it will never entirely recede from view. Rather, the profound and enduring new problem of modern commercial societies is productive and distributive coordination - grounded in the fact that our mutual interdependence as human beings is so great, and yet our practical claims on one another's benevolence are so small.