Reference to the common good has increased in recent political discourse, not only on the right but also on the left. This development partly reflects genuine limitations in the liberal model of politics, and thus should not be dismissed as mere rhetoric. However, appeals to the common good face four difficulties: its social referent; its temporal horizon; its substantive content; and its authoritative identification. The article concludes with a modest suggestion for understanding the common good in complex societies.Keywords common good, Gemeinwohl, public good, public interest, republicanism, Sittlichkeit 'Common good' -how surprising the renaissance of this concept, particularly the role it seems to play on the left side of the political spectrum. The concept is popular not only with conservatives who conceive the social order in terms of natural law, but also recently with the political leaders of the 'new center' and the 'third way'. Striking on both sides is the bold republican pathos that accompanies talk of the common good in the singular. 1 There is nothing new in the fact that central ideas and conceptions of social order are advertised as versions of the common good in the spirit of a reflexive pluralism, in the awareness of the irremediable contestability of all substantive interpretations of the common good. Every interpretation of the common good is only one reading among many, proposed in the knowledge that it must compete with rival interpretations. What is striking, however, and rather unexpected on the political left, 2 is talk of 'the' common good in the singular, which suggests a definitive clarity that brooks no dissent. Proponents of such a common good, which is allegedly clear and uncontested, rise imperiously above the contest of mere special interests and particular