As a highly Pagan poet said to me: “The Reformation happened because people hadn’t the brains to understand Aquinas.” The Church is more immortally important than the State; but the State has its rights, for all that. This Christian duality had always been implicit, as in Christ’s distinction between God and Caesar, or the dogmatic distinction between the natures of Christ.
But St. Thomas has the glory of having seized this double thread as the clue to a thousand things; and thereby created the only creed in which the saints can be sane. It presents itself chiefly, perhaps, to the modern world as the only creed in which the poets can be sane. For there is nobody now to settle the Manichees; and all culture is infected with a faint unclean sense that Nature and all things behind us and below us are bad; that there is only praise to the highbrow in the height. St. Thomas exalted God without lowering Man; he exalted Man without lowering Nature. Therefore, he made a cosmos of common sense; terra viventium; a land of the living.
His philosophy, like his theology, is that of common sense. He does not torture the brain with desperate attempts to explain existence by explaining it away. The first steps of his mind are the first steps of any honest mind; just as the first virtues of his creed could be those of any honest peasant.