SUMMA THEOLOGICA. Thomas Aquinas
Objection 2: Further, if it is a matter of argument, the argument is either from authority or from reason. If it is from authority, it seems unbefitting its dignity, for the proof from authority is the weakest form of proof. But if it is from reason, this is unbefitting its end, because, according to Gregory (Hom. 26), "faith has no merit in those things of which human reason brings its own experience." Therefore sacred doctrine is not a matter of argument.
On the contrary, The Scripture says that a bishop should "embrace that faithful word which is according to doctrine, that he may be able to exhort in sound doctrine and to convince the gainsayers" (Titus 1:9).
I answer that, As other sciences do not argue in proof of their principles, but argue from their principles to demonstrate other truths in these sciences: so this doctrine does not argue in proof of its principles, which are the articles of faith, but from them it goes on to prove something else; as the Apostle from the resurrection of Christ argues in proof of the general resurrection (1 Cor. 15). However, it is to be borne in mind, in regard to the philosophical sciences, that the inferior sciences neither prove their principles nor dispute with those who deny them, but leave this to a higher science; whereas the highest of them, viz. metaphysics, can dispute with one who denies its principles, if only the opponent will make some concession; but if he concede nothing, it can have no dispute with him, though it can answer his objections. Hence Sacred Scripture, since it has no science above itself, can dispute with one who denies its principles only if the opponent admits some at least of the truths obtained through divine revelation; thus we can argue with heretics from texts in Holy Writ, and against those who deny one article of faith, we can argue from another. If our opponent believes nothing of divine revelation, there is no longer any means of proving the articles of faith by reasoning, but only of answering his objections---if he has any---against faith. Since faith rests upon infallible truth, and since the contrary of a truth can never be demonstrated, it is clear that the arguments brought against faith cannot be demonstrations, but are difficulties that can be answered.
Reply to Objection 1: Although arguments from human reason cannot avail to prove what must be received on faith, nevertheless, this doctrine argues from articles of faith to other truths.
Reply to Objection 2: This doctrine is especially based upon arguments from authority, inasmuch as its principles are obtained by revelation: thus we ought to believe on the authority of those to whom the revelation has been made. Nor does this take away from the dignity of this doctrine, for although the argument from authority based on human reason is the weakest, yet the argument from authority based on divine revelation is the strongest. But sacred doctrine makes use even of human reason, not, indeed, to prove faith (for thereby the merit of faith would come to an end), but to make clear other things that are put forward in this doctrine. Since therefore grace does not destroy nature but perfects it, natural reason should minister to faith as the natural bent of the will ministers to charity. Hence the Apostle says: "Bringing into captivity every understanding unto the obedience of Christ" (2 Cor. 10:5). Hence sacred doctrine makes use also of the authority of philosophers in those questions in which they were able to know the truth by natural reason, as Paul quotes a saying of Aratus: "As some also of your own poets said: For we are also His offspring" (Acts 17:28). Nevertheless, sacred doctrine makes use of these authorities as extrinsic and probable arguments; but properly uses the authority of the canonical Scriptures as an incontrovertible proof, and the authority of the doctors of the Church as one that may properly be used, yet merely as probable. For our faith rests upon the revelation made to the apostles and prophets who wrote the canonical books, and not on the revelations (if any such there are) made to other doctors. Hence Augustine says (Epis. ad Hieron. xix, 1): "Only those books of Scripture which are called canonical have I learned to hold in such honor as to believe their authors have not erred in any way in writing them. But other authors I so read as not to deem everything in their works to be true, merely on account of their having so thought and written, whatever may have been their holiness and learning."
Whether Holy Scripture should use metaphors?
Objection 1: It seems that Holy Scripture should not use metaphors. For that which is proper to the lowest science seems not to befit this science, which holds the highest place of all. But to proceed by the aid of various similitudes and figures is proper to poetry, the least of all the sciences. Therefore it is not fitting that this science should make use of such similitudes.
Objection 2: Further, this doctrine seems to be intended to make truth clear. Hence a reward is held out to those who manifest it: "They that explain me shall have life everlasting" (Ecclus. 24:31). But by such similitudes truth is obscured. Therefore, to put forward divine truths by likening them to corporeal things does not befit this science.
Objection 3: Further, the higher creatures are, the nearer they approach to the divine likeness. If therefore any creature be taken to represent God, this representation ought chiefly to be taken from the higher creatures, and not from the lower; yet this is often found in Scriptures.
On the contrary, It is written (Osee 12:10): "I have multiplied visions, and I have used similitudes by the ministry of the prophets." But to put forward anything by means of similitudes is to use metaphors. Therefore this sacred science may use metaphors.
I answer that, It is befitting Holy Writ to put forward divine and spiritual truths by means of comparisons with material things. For God provides for everything according to the capacity of its nature. Now it is natural to man to attain to intellectual truths through sensible objects, because all our knowledge originates from sense. Hence in Holy Writ, spiritual truths are fittingly taught under the likeness of material things. This is what Dionysius says (Coel. Hier. i): "We cannot be enlightened by the divine rays except they be hidden within the covering of many sacred veils." It is also befitting Holy Writ, which is proposed to all without distinction of persons---"To the wise and to the unwise I am a debtor" (Rm. 1:14)---that spiritual truths be expounded by means of figures taken from corporeal things, in order that thereby even the simple who are unable by themselves to grasp intellectual things may be able to understand it.
Reply to Objection 1: Poetry makes use of metaphors to produce a representation, for it is natural to man to be pleased with representations. But sacred doctrine makes use of metaphors as both necessary and useful.
Reply to Objection 2: The ray of divine revelation is not extinguished by the sensible imagery wherewith it is veiled, as Dionysius says (Coel. Hier. i); and its truth so far remains that it does not allow the minds of those to whom the revelation has been made, to rest in the metaphors, but raises them to the knowledge of truths; and through those to whom the revelation has been made others also may receive instruction in these matters. Hence those things that are taught metaphorically in one part of Scripture, in other parts are taught more openly. The very hiding of truth in figures is useful for the exercise of thoughtful minds and as a defense against the ridicule of the impious, according to the words "Give not that which is holy to dogs" (Mt. 7:6).
Reply to Objection 3: As Dionysius says, (Coel. Hier. i) it is more fitting that divine truths should be expounded under the figure of less noble than of nobler bodies, and this for three reasons. Firstly, because thereby men's minds are the better preserved from error. For then it is clear that these things are not literal descriptions of divine truths, which might have been open to doubt had they been expressed under the figure of nobler bodies, especially for those who could think of nothing nobler than bodies. Secondly, because this is more befitting the knowledge of God that we have in this life. For what He is not is clearer to us than what He is. Therefore similitudes drawn from things farthest away from God form within us a truer estimate that God is above