On the Catholic Priesthood
Doctrine of the Church
The doctrine of the Church is unchangeable in the sense that it cannot contradict itself; it is also unchangeable in the sense that nothing can be added to the deposit of revelation. But there is a sense in which the treasure of revealed doctrine is susceptible of development. If we cannot add to it, we can nevertheless gain a clearer and more certain knowledge of its content. In this sense the Church, like every organized body and every living being, is subject to the conditions of growth and development.
Wonderful to say, God makes use of the same means to stimulate the growth and development of doctrine in His Church that the powers of hell make use of to corrupt it, namely, the assaults of unbelief and heresy. There must be also heresies, says St. Paul. These are the inevitable results of the free will of man and of the imperious tendency within him to rebel against the authority of God. But such waywardness and rebellion go only so far as God in His providence permits them to go; they manifest themselves at a time prefixed by Him, and their success is always in the order and measure best suited to the carrying out of His designs.
The author having shown how error proceeds, that it first attacks the unity of God, next the dogma of the Incarnation, next that of the Blessed Trinity, and lastly that of human free will and grace; how the Doctors of the Church by their learning and writings repelled these assaults, and how the Church brought the successive conflicts to a close as they arose by her infallible decisions, thus setting up one by one the columns which sustain the edifice of divine science, goes on to point out how St. Thomas brought together all these scattered materials, arranging and coordinating them in a magnificent synthesis, and presenting them in his Summa in a structure at once systematic and complete.
How happy an alliance, he goes on to say, between revealed truth and the fundamental laws of the human mind! How naturally the teachings of the Fathers fit into this plan, and with such method that one would say that it had all been thought out a priori! How intimate the connection of dogma with dogma! What wonderful analogies are presented at every step, in the consideration of which the mind is borne on to the origin of all things! Above all, what admirable unity! God is considered in His essence and His inner life; He is considered as He manifests Himself externally in the double creation of spirit and matter, and in the creation of man, the precious link which binds the two together; He is considered in His relation to creatures, as leading them back to Himself by the moral law and grace, by the Incarnation and the Sacraments, by rewarding the good and punishing the evil. Here is the whole of theology; here in a sense is the entire universe, with the motive of its being, its origin and its destiny. What book can be compared with a book like this, which sets forth these truths in a style so clear and so graceful, and as luminous as the azure sky! What science is comparable with this science?
Of all sciences, says Aristotle, speaking of philosophy, there is none that surpasses this in dignity, because there is none more divine. Now, a science can be divine in two senses, either because it appertains to God or because it treats of the things of God. The science in question claims this double prerogative, first because God is its object, inasmuch as He is the Principle and Cause of everything that exists; and next because He is its subject, it being wholly occupied with Him. (Metaph. Lib.1) Who does not see that this eulogy of philosophy properly applies only to theology?
To learn more about St. Thomas: Aquinas 101