In my Catholic Social Thought class, we are reading a portion of Jacques Maritain’s Man and the State (1951).  Maritain was a Catholic liberal (by which I mean that he was a Catholic for whom liberty and equality were fundamentally important rights) writing primarily in the post-War period.  His writings deeply influenced the proceedings of the Second Vatican Council.  Here is an interesting passage about the nonbeliever’s reasons for affirming the liberty of the church (from Chapter 6 — “Church and State”).  It is written in a style that assumes a certain degree of consensus, an assumption which may well have been a product of its times (this makes it even more interesting as a subject of study).  One particularly striking feature of the passage is that Maritain begins not with a discussion of a value such as liberty or equality, but by considering what “the Church, or the Churches” ought to represent for nonbelievers.  That is, Maritain begins with the concrete institution rather than with the abstract value:

To begin with, what is the Church for the unbeliever?  In the eyes of the unbeliever, the Church is, or the Churches are, organized bodies or associations especially concerned with the religious needs and creeds of a number of his fellow-men, that is, with spiritual values to which they have committed themselves, and to which their moral standards are appendent.  These spiritual values are part — in actual fact the most important part, as history shows it — of those supra-temporal goods with respect to which, even in the natural order, the human person transcends, as we have seen, political society, and which constitute the moral heritage of mankind, the spiritual common good of civilization or of the community of minds.  Even though the unbeliever does not believe in these particular spiritual values, he has to respect them.  In his eyes the Church, or the Churches, are in the social community particular bodies which must enjoy that right to freedom which is but one, not only with the right to free association naturally belonging to the human person, but with the right freely to believe the truth recognized by one’s conscience, that is, with the most basic and inalienable of all human rights.  Thus the unbeliever, from his own point of view — I mean, of course, the unbeliever who, at least, is not an unbeliever in reason, and, furthermore, who is a democratically-minded unbeliever — acknowledges as a normal and necessary thing the freedom of the Church, or of the Churches.  (150)