O’Donovan continues his article by asking in what sense pluralism’s public reason is public. Public and private necessitate one another, and “the private is defined negatively, by privation . . . by walling off, excluding, refusing entry. Private thought, domestic privacy, property, private association, and so on are those withheld from universal access.”

Public negates this negation, or so it seems. But public areas also exclude: A public school is open to all students, but not to everyone at all. When applied to “reason,” the word “public” is even more exclusionary, it is “constructed by privation, like another kind of private sphere” in that it doesn’t admit “moral identifies formed behind its back, in private.” The public of public reason is not the town square but “more like a walled and barbed-wired garrison, bristling with warnings against entry by unauthorized personnel. It is a public conceived as another kind of privacy.”

Public so conceived creates problems as we try to move from “private” to “public.”

We know that the disciplines of the one order are not the same as the disciplines of the other, but the two must cohere. There must be a way of “linking the performance of any individual in public and the same individual’s performance in private.” If the two are separated, then public disciplines are no longer disciplines but simple prohibitions. Public reason thus “must bypass the moral reasoning of those who participate in it,” and this can only leave public actors “devoid of reasons that could lead us to act.” As a result the “second-order” reasons of public reason “are, in fact, not reasons at all, because they do not derive from, or connect with, first-order reasons.”

For Christians, what public reason excludes is charity: “Charity is a hegemonic principle; that is to say, it generates not only private but public forms of conduct, shaping a homologous identity that can move between the private and the public. If hegemonic traditions are to be expelled from society, charity, a tradition born of the Christian gospel.”

So: “Public reason” is public in the sense that it is a very tightly defined private space.