1. Theology accepts the depositum fidei, and studies its documents, Scripture and tradition, under the guidance of the teaching Church. This is positive theology, which includes study of biblical theology, of the documents and organs of tradition, of the various forms of the living magisterium.

2. The next step is analysis of revealed truths, in particular of the more fundamental truths, to establish the precise meaning of the subject and the predicate by which that truth is expressed. Take, for example, this sentence: The Word was made flesh. Theological analysis shows that the sentence means: The Word, who is God, became man. This labor of conceptual analysis appears in his first articles when St. Thomas begins a new treatise, on the Trinity, for example, or the Incarnation. In these articles you will search in vain for a theological conclusion. You will find but simple analysis, sometimes grammatical, but generally conceptual, of the subject and predicate of the revealed proposition.

3. On the next step theology defends revealed truths by showing either that they are contained in the deposit of faith, or that they contain no manifest impossibility. [255] No effort is made to demonstrate positively the intrinsic possibility of the mystery. If such possibility could be demonstrated by reason alone, then would the existence of the mystery be likewise demonstrated, for the Trinity is a being, not contingent, but necessary. The only thing attempted in this apologetic procedure is to show that there is no evident contradiction in the proposition which enunciates the dogma. God is triune, and one. He is "one" by nature, and "triune" in so far as this unique nature is possessed by three distinct persons, as in a triangle, to illustrate, the three angles have the same surface.

4. On the fourth level theology uses arguments of appropriateness, to illumine, not to demonstrate, revealed truth. Thus, to clarify the dogma, say, of the Word's eternal generation or that of the redemptive Incarnation, theology appeals to the following principle: God is by nature self-diffusive; and the more elevated good is, the more intimately and abundantly does it communicate itself. [256] Hence it is appropriate that God, the supreme Good, communicate His entire nature in the eternal generation of the Word, and that the Word be incarnate for our salvation. [257] These mysteries, so runs the common theological doctrine, cannot be proved, and cannot be disproved, and although they do have a persuasive probability, they are held with certitude by faith alone. [258] .

5. Further, theology has recourse to explicative reasoning, to demonstrate, often in strictest form, a truth, not new, but implicitly contained in a revealed truth. This procedure passes from a confused formulation of a truth to a more distinct formulation of the same truth. To illustrate: take the sentence, The Word, which was God, was made flesh. Against the Arians, that sentence was thus expressed: The Word, consubstantial with the Father, was made man. This consubstantiality with the Father, whatever some writers say, is much more than a theological conclusion, deduced illatively from a revealed truth. It is a truth identical, only more explicitly stated, with that found in the Prologue of St. John's Gospel.

A second illustration: Thou art Peter, and upon this rock I will build My church, and gates of hell shall not prevail against it. [259] This same truth is expressed, only more explicitly, as follows: The sovereign pontiff, successor of St. Peter, is infallible when ex cathedra he teaches the universal Church in matters of faith and morals. This latter formula does not enunciate a new truth deduced from the first. In each sentence we have the same subject and the same predicate, joined by the verb "to be." But the language, metaphorical in the first formula, becomes proper, scientific, in the second.

6a. Again, theology uses reasoning, not merely explicative, but strictly and objectively illative, to draw from two revealed truths a third truth, revealed elsewhere, often less explicitly, in Scripture and tradition. This kind of illative reasoning, frequent in theology, unites to the articles of the Creed other truths of faith, and thus forms a body of doctrine, with all constituent truths in mutual relation and subordination. This body of doctrine [260] stands higher than all theological systems, higher even than theological science itself. Thus we understand the title: De sacra doctrina, given by St. Thomas to the first question in the Summa theologiae. The first article of that question is entitled, doctrina fidei. In the following articles, the subject is doctrina theologica, sacra theologia, which is declared to be a science, itself superior to systems that have not, properly speaking, attained the status of science. How the various elements of this body of doctrine are grouped around the articles of faith becomes apparent only by that objective illative procedure, of which we are now speaking, which from two revealed truths deduces a third which has also been revealed, even at times explicitly, in Scripture or tradition. To illustrate, let us take these two statements: first, "Jesus is truly God," second, "Jesus is truly man." From these two statements there follows, by a strictly illative process, this third statement: Jesus has two minds and two wills. And this third truth is elsewhere explicitly revealed, in the words of Jesus Himself: "Not as I will, but as Thou wilt." [261] .

Now a conclusion of this kind, a conclusion revealed elsewhere, can evidently be defined by the Church as a dogma of faith. Does it follow, then, as is sometimes said, that in such cases theological reasoning is useless? Not at all. Reasoning in such cases gives us understanding of a truth which before we accepted only by faith. The characteristic of demonstration is not necessarily to discover a new truth, but to make the truth known in its source, its cause. In this kind of reasoning we realize the full force of the classic definition of theology: faith seeking self-understanding. [262] This realization is very important. [263] .

6b. Theology uses reasoning, illative in the proper sense, to deduce from two revealed truths a third truth not revealed elsewhere, that is, not revealed in itself, but only in the other two truths of which it is the fruit. Thomists generally admit that such a conclusion, derived from two truths of faith, is substantially revealed, and hence can be defined as dogma. Reasoning enters here only to bring together two truths which of themselves suffice to make the third truth known. The knowledge of the third truth depends on the reasoning, not as cause, but only as condition. [264] .

6c. Lastly, from one truth of faith and one of reason, theology, by a process strictly illative, deduces a third truth. Such a truth, since it is not revealed simply and properly speaking (simpliciter): is revealed only virtually, that is, in its cause. A truth of this kind, strictly deduced, lies in the domain, not of faith, but of theological science.

A subdivision enters here. In every reasoning process the major proposition, being more universal, is more important than the minor. Now, in the present kind of argument the truth of faith may be either the major or the minor. If the major is of faith, the conclusion is nearer to revelation than is a conclusion where the truth of faith forms the minor.

Many theologians, in particular many Thomists, [265] maintain that a conclusion of this kind, where either premise is a truth of reason, cannot be defined as a dogma of faith. They argue thus: Such a conclusion has, simply speaking, not been revealed. It has been revealed only in an improper sense (secundum quid): only virtually, in its cause. It is, properly speaking, a deduction from revelation. It is true, the Church can condemn the contradictory of such a conclusion, but if she does, she condemns it, not as heretical, that is, as contrary to the faith, but as erroneous, that is, contrary to an accepted theological conclusion.

Exemplifications of the six theological procedures we have now outlined appear throughout the Summa, particularly in the first question, and in the structure of all the theological treatises of St. Thomas.

The reason is now clear, we think, why we cannot admit the two contrary opinions we spoke of at the beginning of this section. Not all theological conclusions can be defined as dogmas of faith. In particular, we cannot admit that the Church can define as dogma, as simply revealed by God, a truth which is not revealed simpliciter, but only virtually, secundum quid, in causa.

On the other hand, theology can very well reach certitude in such a conclusion which lies in its own proper domain, which is more than a conclusion of metaphysics placed at the service of theology. Further, the most important task of theology is evidently not the drawing of these conclusions, but rather the explanation of the truths of faith themselves, penetration into their deeper meaning, into their mutual relation and subordination. In this task theology has, as aids, the gifts of knowledge and wisdom, by which theological labor becomes more penetrating and savorous. Conclusions are thus sought, not for their own sake, but as a road to more perfect understanding of the truths of faith. Such labor, manifesting the deep inner power of faith, is proportioned to the scope so beautifully expressed by the Council of the Vatican: to attain, God granting, some understanding of the mysteries, an understanding in every way most fruitful. [266] .

Article Three: The Evolution Of Dogma

The conception of theology outlined in the foregoing pages, though it denies the definability of theological conclusions properly so called, still occupies an important place in the evolution of dogma.

St. Thomas is certainly not unacquainted with dogmatic progress. Let us but recall his remarks concerning venatio ("hunting"): in his commentary on the Later Analytics, [267] on how to find, first a definition that is merely nominal (quid nominis): which expresses a confused notion of the thing to be defined, and, second, how to pass from this nominal definition to one that is clear, distinct and real. The most important task both of philosophy and of theology lies in this methodic step from the confused concept of common sense (or of Christian sense) to a concept that is clear and distinct. This process is not that from premise to conclusion. Rather, we deal with one concept all the way through, a concept, at first generic, becoming by precision specific, and then, by induction, distinguished from concepts which more or less closely resemble it. In this fashion have been reached the precise definitions now prevailing, of substance, of life, of man, of soul, of intellect, of will, of free will, of all the various virtues.

This same conceptual analysis has furnished great contributions to the refining of concepts indispensable in dogmatic formulas, of being, say, created and uncreated, of unity, of truth, of goodness, ontological and moral; concepts, further, of analogy relative to God, of divine wisdom, of the divine will, of uncreated love, of providence, of predestination; or again, of nature, of person, of relation, in giving precise formulas to the teaching on the Trinity and the Incarnation; of grace, free will, merit, sin, virtue, faith, hope, charity, justification; of sacrament, character, sacramental grace, transubstantiation, contrition; of beatitude, pain in purgatory and in hell, and so on.

Thus we see that immense conceptual labor is pre-required before we can proceed to deduce theological conclusions. Confused concepts, expressed in nominal definitions or in current terms of Scripture and tradition, must become distinct and precise, if we would refute the heresies that deform revelation itself. Long schooling is needed before we can grasp the profound import, sublimity, and fertility of the principles which faith gives us.

Here lies the most important contribution of theological science to dogmatic development. And the degree of merit which a theological system will have in efficacious promotion of this development will depend on the universality of its synthesis. A synthesis generated from the idea of God, author of all things in the order both of nature and of grace, must necessarily be universal, whereas a synthesis dominated by particular, partial, and subordinated concepts, the free will of man, say, cannot reach a true universality, attainable only under a spiritual sun which illumines all parts of the system.

As image of the relation between theological systems and faith, we suggest a polygon inscribed in a circle. The circle stands for the simplicity and superiority of the doctrines of faith. The inscribed polygon, with its many angles, contains the rich details of the theological system. The polygon traced by Nominalism differs by far from that initiated by St. Augustine and elaborated by St. Thomas. But even if it is conceived as perfect as possible, the polygon can never have the transcendent simplicity of the circle. Theology, likewise, the more it advances, the more does it humiliate itself before the superiority of that faith which it never ceases to set in relief. Theology is a commentary ever drawing attention to the word of God which it comments on. Theology, like the Baptist, forgets itself in the cry: Behold the Lamb of God, who takes away the sin of the world.