Political argument in liberal democracies is characterized by both agreement and disagreement. The disagreement is obvious. Citizens profess a wide variety of conflicting beliefs about politics, morality, and religion. Competitive elections, by their structure, encourage the expression and clarification of disagreement. Among the causes of this pervasive disagreement are self-interest, human fallibility, and the complexity of difficult moral questions. The agreement in political argument is less obvious but very important. Just as we must agree on certain linguistic conventions in order to communicate at all, so also we must agree on at least some moral ideas if we are to have moral debates that are intelligible. Even persons who are moral relativists can acknowledge that within particular communities there are particular ideas and claims that are understood to have moral weight.1 In liberal democracies, most people will acknowledge in principle that their fellow citizens are moral agents, that they are equals in at least the sense that we should treat them according to some moral standard of reciprocity rather than as objects we can manipulate according to our desires, that the same moral rules should apply to all of us, and that we should all be able to know what those rules are. I refer to these four ideas as moral agency, moral equality, generality, and publicity. Many people give only lip service to these ideas, and our practice, both individually and collectively, often fails to respect them. Nonetheless they provide ideas that most persons recognize as carrying moral weight and provide a framework in which moral debate about politics can begin.
This broad description of the problem of political disagreement, some of its causes, and some of the relevant moral intuitions is one that a wide variety of citizens and political theorists could accept. Nothing in the above description of the modern predicament is inconsistent with theoretical approaches as diverse as Michael Walzer's communitarianism, John Rawls's political liberalism, Robert Nozick's libertarianism, or
1 See, for example, Michael Walzer, Spheres of Justice (New York: Basic Books, 1983),