Right Reason, that is, Reason rightly exercised, leads the mind to the Catholic Faith, and plants it there, and teaches it in all its religious speculations to act under its guidance. But Reason, considered as a real agent in the world, and as an operative principle in man’s nature, with an historical course and with definite results, is far from taking so straight and satisfactory a direction. It considers itself from first to last independent and supreme; it requires no external authority; it makes a religion for itself. Even though it accepts Catholicism, it does not go to sleep; it has an action and development of its own, as the passions have, or the moral sentiments, or the principle of self-interest. Divine grace, to use the language of Theology, does not by its presence supersede nature; nor is nature at once brought into simple concurrence and coalition with grace. Nature pursues its course, now coincident with that of grace, now parallel to it, now across, now divergent, now counter, in proportion to its own imperfection and to the attraction and influence which grace exerts over it. And what takes place as regards other principles of our nature and their developments is found also as regards the Reason. There is, we know, a Religion of enthusiasm, of superstitious ignorance of statecraft; and each has that in it which resembles Catholicism, and that again which contradicts Catholicism. There is the Religion of a warlike people, and of a pastoral people; there is a Religion of rude times, and in like manner there is a Religion of civilized times, of the cultivated intellect, of the philosopher, scholar, and gentleman. This is that Religion of Reason, of which I speak. Viewed in itself, however near it comes to Catholicism, it is of course simply distinct from it; for Catholicism is one whole, and admits of no compromise or modification. Yet this is to view it in the abstract; in matter of fact, and in reference to individuals, we can have no difficulty in conceiving this philosophical Religion present in a Catholic country, as a spirit influencing men to a certain extent, for good or for bad or for both,–a spirit of the age, which again may be found, as among Catholics, so with still greater sway and success in a country not Catholic, yet specifically the same in such a country as it exists in a Catholic community. The problem then before us to-day, is to set down some portions of the outline, if we can ascertain them, of the Religion of Civilization, and to determine how they lie relatively to those principles, doctrines, and rules, which Heaven has given us in the Catholic Church.
– from The Idea of a University Defined and Illustrated (1852)