The whole premise of the public argument, if it is to be civilized and civilizing, is that the consensus is real, that among the people everything is not in doubt, but that there is a core of agreement, accord, concurrence, acquiescence. We hold certain truths, therefore we can argue about them. It seems to have been one of the corruptions of intelligence by positivism to assume that argument ends when agreement is reached. In a basic sense the reverse is true. There can be no argument except on the premise, and within a context, of agreement. Mutatis mutandis, this is true of scientific, philosophical, and theological argument. It is no less true of political argument.
On its most imperative level the public argument within the City and about the City’s affairs begins with the agreement that there is a reality called, in the phrase of Leo XIII, patrimonium generis humani, a heritage of an essential truth, a tradition of rational belief, that sustains the structure of the City and furnishes the substance of civil life. It was to this patrimony that the Declaration of Independence referred: “These are the truths we hold.” This is the first utterance of a people. By it a people establishes its identity, and under decent respect to the opinions of mankind declares its purposes within the community of nations.