"THE old unpsychological school of instructors used to say: "What possible sense can there be in mixing up arithmetic with religion?" But arithmetic is mixed up with religion, or at the worst with philosophy. It does make a great deal of difference whether the instructor implies that truth is real, or relative, or changeable, or an illusion. The man who said, "Two and two may make five in the fixed stars," was teaching arithmetic in an anti-rational way, and, therefore, in an anti-Catholic way. The Catholic is much more certain about the fixed truths than about the fixed stars."
~G.K. Chesterton: The Common Man.