Summa Theologiae/First Part/Question 1
Treatise on Sacred Doctine
Question. 1 - THE NATURE AND EXTENT OF SACRED DOCTRINE (TEN ARTICLES)
- To place our purpose within proper limits, we first endeavor to investigate the nature and extent of this sacred doctrine. Concerning this there are ten points of inquiry:
(1) Whether it is necessary?
(2) Whether it is a science?
(3) Whether it is one or many?
(4) Whether it is speculative or practical?
(5) How it is compared with other sciences?
(6) Whether it is the same as wisdom?
(7) Whether God is its subject-matter?
(8) Whether it is a matter of argument?
(9) Whether it rightly employs metaphors and similes?
(10) Whether the Sacred Scripture of this doctrine may be expounded in different senses?
Art. 1 - Whether, besides philosophy, any further doctrine is required?
Objection i. It seems that, besides philosophical science, we have no need of any further knowledge. For man should not seek to know what is above reason: Seek not the things that are too high for thee (Ecclus. 3:22).But whatever is not above reason is fully treated of in philosophical science.
Objection 2: Further, knowledge can be concerned only with being, for nothing can be known, save what is true; and all that is, is true. But everything that is, is treated of in philosophical science---even God Himself; so that there is a part of philosophy called theology, or the divine science, as Aristotle has proved (Metaph. vi). Therefore, besides philosophical science, there is no need of any further knowledge.
On the contrary, It is written (2 Tim. 3:16): "All Scripture, inspired of God is profitable to teach, to reprove, to correct, to instruct in justice." Now Scripture, inspired of God, is no part of philosophical science, which has been built up by human reason. Therefore it is useful that besides philosophical science, there should be other knowledge, i.e. inspired of God.
I answer that, It was necessary for man's salvation that there should be a knowledge revealed by God besides philosophical science built up by human reason. Firstly, indeed, because man is directed to God, as to an end that surpasses the grasp of his reason: "The eye hath not seen, O God, besides Thee, what things Thou hast prepared for them that wait for Thee" (Is. 64:4). But the end must first be known by men who are to direct their thoughts and actions to the end. Hence it was necessary for the salvation of man that certain truths which exceed human reason should be made known to him by divine revelation. Even as regards those truths about God which human reason could have discovered, it was necessary that man should be taught by a divine revelation; because the truth about God such as reason could discover, would only be known by a few, and that after a long time, and with the admixture of many errors. Whereas man's whole salvation, which is in God, depends upon the knowledge of this truth. Therefore, in order that the salvation of men might be brought about more fitly and more surely, it was necessary that they should be taught divine truths by divine revelation. It was therefore necessary that besides philosophical science built up by reason, there should be a sacred science learned through revelation.
Reply to Objection 1: Although those things which are beyond man's knowledge may not be sought for by man through his reason, nevertheless, once they are revealed by God, they must be accepted by faith. Hence the sacred text continues, "For many things are shown to thee above the understanding of man" (Ecclus. 3:25). And in this, the sacred science consists.
Reply to Objection 2: Sciences are differentiated according to the various means through which knowledge is obtained. For the astronomer and the physicist both may prove the same conclusion: that the earth, for instance, is round: the astronomer by means of mathematics (i.e. abstracting from matter), but the physicist by means of matter itself. Hence there is no reason why those things which may be learned from philosophical science, so far as they can be known by natural reason, may not also be taught us by another science so far as they fall within revelation. Hence theology included in sacred doctrine differs in kind from that theology which is part of philosophy.
Art. 2 - Whether sacred doctrine is a science?
Objection 1: It seems that sacred doctrine is not a science. For every science proceeds from self-evident principles. But sacred doctrine proceeds from articles of faith which are not self-evident, since their truth is not admitted by all: "For all men have not faith" (2 Thess. 3:2). Therefore sacred doctrine is not a science.
Objection 2: Further, no science deals with individual facts. But this sacred science treats of individual facts, such as the deeds of Abraham, Isaac and Jacob and such like. Therefore sacred doctrine is not a science.
On the contrary, Augustine says (De Trin. xiv, 1) "to this science alone belongs that whereby saving faith is begotten, nourished, protected and strengthened." But this can be said of no science except sacred doctrine. Therefore sacred doctrine is a science.
I answer that, Sacred doctrine is a science. We must bear in mind that there are two kinds of sciences. There are some which proceed from a principle known by the natural light of intelligence, such as arithmetic and geometry and the like. There are some which proceed from principles known by the light of a higher science: thus the science of perspective proceeds from principles established by geometry, and music from principles established by arithmetic. So it is that sacred doctrine is a science because it proceeds from principles established by the light of a higher science, namely, the science of God and the blessed. Hence, just as the musician accepts on authority the principles taught him by the mathematician, so sacred science is established on principles revealed by God.
Reply to Objection 1: The principles of any science are either in themselves self-evident, or reducible to the conclusions of a higher science; and such, as we have said, are the principles of sacred doctrine.
Reply to Objection 2: Individual facts are treated of in sacred doctrine, not because it is concerned with them principally, but they are introduced rather both as examples to be followed in our lives (as in moral sciences) and in order to establish the authority of those men through whom the divine revelation, on which this sacred scripture or doctrine is based, has come down to us.
Art. 3 - Whether sacred doctrine is one science?
Objection 1: It seems that sacred doctrine is not one science; for according to the Philosopher (Poster. i) "that science is one which treats only of one class of subjects." But the creator and the creature, both of whom are treated of in sacred doctrine, cannot be grouped together under one class of subjects. Therefore sacred doctrine is not one science.
Objection 2: Further, in sacred doctrine we treat of angels, corporeal creatures and human morality. But these belong to separate philosophical sciences. Therefore sacred doctrine cannot be one science.
On the contrary, Holy Scripture speaks of it as one science: "Wisdom gave him the knowledge [scientiam] of holy things" (Wis. 10:10).
I answer that, Sacred doctrine is one science. The unity of a faculty or habit is to be gauged by its object, not indeed, in its material aspect, but as regards the precise formality under which it is an object. For example, man, ass, stone agree in the one precise formality of being colored; and color is the formal object of sight. Therefore, because Sacred Scripture considers things precisely under the formality of being divinely revealed, whatever has been divinely revealed possesses the one precise formality of the object of this science; and therefore is included under sacred doctrine as under one science.
Reply to Objection 1: Sacred doctrine does not treat of God and creatures equally, but of God primarily, and of creatures only so far as they are referable to God as their beginning or end. Hence the unity of this science is not impaired.
Reply to Objection 2: Nothing prevents inferior faculties or habits from being differentiated by something which falls under a higher faculty or habit as well; because the higher faculty or habit regards the object in its more universal formality, as the object of the "common sense" is whatever affects the senses, including, therefore, whatever is visible or audible. Hence the "common sense," although one faculty, extends to all the objects of the five senses. Similarly, objects which are the subject-matter of different philosophical sciences can yet be treated of by this one single sacred science under one aspect precisely so far as they can be included in revelation. So that in this way, sacred doctrine bears, as it were, the stamp of the divine science which is one and simple, yet extends to everything.
Art. 4 - Whether sacred doctrine is a practical science?
Objection 1: It seems that sacred doctrine is a practical science; for a practical science is that which ends in action according to the Philosopher (Metaph. ii). But sacred doctrine is ordained to action: "Be ye doers of the word, and not hearers only" (James 1:22). Therefore sacred doctrine is a practical science.
Objection 2: Further, sacred doctrine is divided into the Old and the New Law. But law implies a moral science which is a practical science. Therefore sacred doctrine is a practical science.
On the contrary, Every practical science is concerned with human operations; as moral science is concerned with human acts, and architecture with buildings. But sacred doctrine is chiefly concerned with God, whose handiwork is especially man. Therefore it is not a practical but a speculative science.
I answer that, Sacred doctrine, being one, extends to things which belong to different philosophical sciences because it considers in each the same formal aspect, namely, so far as they can be known through divine revelation. Hence, although among the philosophical sciences one is speculative and another practical, nevertheless sacred doctrine includes both; as God, by one and the same science, knows both Himself and His works. Still, it is speculative rather than practical because it is more concerned with divine things than with human acts; though it does treat even of these latter, inasmuch as man is ordained by them to the perfect knowledge of God in which consists eternal bliss. This is a sufficient answer to the Objections.
Art. 5 - Whether sacred doctrine is nobler than other sciences?
Objection 1: It seems that sacred doctrine is not nobler than other sciences; for the nobility of a science depends on the certitude it establishes. But other sciences, the principles of which cannot be doubted, seem to be more certain than sacred doctrine; for its principles---namely, articles of faith---can be doubted. Therefore other sciences seem to be nobler.
Objection 2: Further, it is the sign of a lower science to depend upon a higher; as music depends on arithmetic. But sacred doctrine does in a sense depend upon philosophical sciences; for Jerome observes, in his Epistle to Magnus, that "the ancient doctors so enriched their books with the ideas and phrases of the philosophers, that thou knowest not what more to admire in them, their profane erudition or their scriptural learning." Therefore sacred doctrine is inferior to other sciences.
On the contrary, Other sciences are called the handmaidens of this one: "Wisdom sent her maids to invite to the tower" (Prov. 9:3).
I answer that, Since this science is partly speculative and partly practical, it transcends all others speculative and practical. Now one speculative science is said to be nobler than another, either by reason of its greater certitude, or by reason of the higher worth of its subject-matter. In both these respects this science surpasses other speculative sciences; in point of greater certitude, because other sciences derive their certitude from the natural light of human reason, which can err; whereas this derives its certitude from the light of divine knowledge, which cannot be misled: in point of the higher worth of its subject-matter because this science treats chiefly of those things which by their sublimity transcend human reason; while other sciences consider only those things which are within reason's grasp. Of the practical sciences, that one is nobler which is ordained to a further purpose, as political science is nobler than military science; for the good of the army is directed to the good of the State. But the purpose of this science, in so far as it is practical, is eternal bliss; to which as to an ultimate end the purposes of every practical science are directed. Hence it is clear that from every standpoint, it is nobler than other sciences.
Reply to Objection 1: It may well happen that what is in itself the more certain may seem to us the less certain on account of the weakness of our intelligence, "which is dazzled by the clearest objects of nature; as the owl is dazzled by the light of the sun" (Metaph. ii, lect. i). Hence the fact that some happen to doubt about articles of faith is not due to the uncertain nature of the truths, but to the weakness of human intelligence; yet the slenderest knowledge that may be obtained of the highest things is more desirable than the most certain knowledge obtained of lesser things, as is said in de Animalibus xi.
Reply to Objection 2: This science can in a sense depend upon the philosophical sciences, not as though it stood in need of them, but only in order to make its teaching clearer. For it accepts its principles not from other sciences, but immediately from God, by revelation. Therefore it does not depend upon other sciences as upon the higher, but makes use of them as of the lesser, and as handmaidens: even so the master sciences make use of the sciences that supply their materials, as political of military science. That it thus uses them is not due to its own defect or insufficiency, but to the defect of our intelligence, which is more easily led by what is known through natural reason (from which proceed the other sciences) to that which is above reason, such as are the teachings of this science.
Art. 6 - Whether this doctrine is the same as wisdom?
Objection 1: It seems that this doctrine is not the same as wisdom. For no doctrine which borrows its principles is worthy of the name of wisdom; seeing that the wise man directs, and is not directed (Metaph. i). But this doctrine borrows its principles. Therefore this science is not wisdom.
Objection 2: Further, it is a part of wisdom to prove the principles of other sciences. Hence it is called the chief of sciences, as is clear in Ethic. vi. But this doctrine does not prove the principles of other sciences. Therefore it is not the same as wisdom.
Objection 3: Further, this doctrine is acquired by study, whereas wisdom is acquired by God's inspiration; so that it is numbered among the gifts of the Holy Spirit (Is. 11:2). Therefore this doctrine is not the same as wisdom.
On the contrary, It is written (Dt. 4:6): "This is your wisdom and understanding in the sight of nations."
I answer that, This doctrine is wisdom above all human wisdom; not merely in any one order, but absolutely. For since it is the part of a wise man to arrange and to judge, and since lesser matters should be judged in the light of some higher principle, he is said to be wise in any one order who considers the highest principle in that order: thus in the order of building, he who plans the form of the house is called wise and architect, in opposition to the inferior laborers who trim the wood and make ready the stones: "As a wise architect, I have laid the foundation" (1 Cor. 3:10). Again, in the order of all human life, the prudent man is called wise, inasmuch as he directs his acts to a fitting end: "Wisdom is prudence to a man" (Prov. 10: 23). Therefore he who considers absolutely the highest cause of the whole universe, namely God, is most of all called wise. Hence wisdom is said to be the knowledge of divine things, as Augustine says (De Trin. xii, 14). But sacred doctrine essentially treats of God viewed as the highest cause---not only so far as He can be known through creatures just as philosophers knew Him---"That which is known of God is manifest in them" (Rm. 1:19)---but also as far as He is known to Himself alone and revealed to others. Hence sacred doctrine is especially called wisdom.
Reply to Objection 1: Sacred doctrine derives its principles not from any human knowledge, but from the divine knowledge, through which, as through the highest wisdom, all our knowledge is set in order.
Reply to Objection 2: The principles of other sciences either are evident and cannot be proved, or are proved by natural reason through some other science. But the knowledge proper to this science comes through revelation and not through natural reason. Therefore it has no concern to prove the principles of other sciences, but only to judge of them. Whatsoever is found in other sciences contrary to any truth of this science must be condemned as false: "Destroying counsels and every height that exalteth itself against the knowledge of God" (2 Cor. 10:4,5).
Reply to Objection 3: Since judgment appertains to wisdom, the twofold manner of judging produces a twofold wisdom. A man may judge in one way by inclination, as whoever has the habit of a virtue judges rightly of what concerns that virtue by his very inclination towards it. Hence it is the virtuous man, as we read, who is the measure and rule of human acts. In another way, by knowledge, just as a man learned in moral science might be able to judge rightly about virtuous acts, though he had not the virtue. The first manner of judging divine things belongs to that wisdom which is set down among the gifts of the Holy Ghost: "The spiritual man judgeth all things" (1 Cor. 2:15). And Dionysius says (Div. Nom. ii): "Hierotheus is taught not by mere learning, but by experience of divine things." The second manner of judging belongs to this doctrine which is acquired by study, though its principles are obtained by revelation.
Art. 7 - Whether God is the object of this science?
Objection 1: It seems that God is not the object of this science. For in every science, the nature of its object is presupposed. But this science cannot presuppose the essence of God, for Damascene says (De Fide Orth. i, iv): "It is impossible to define the essence of God." Therefore God is not the object of this science.
Objection 2: Further, whatever conclusions are reached in any science must be comprehended under the object of the science. But in Holy Writ we reach conclusions not only concerning God, but concerning many other things, such as creatures and human morality. Therefore God is not the object of this science.
On the contrary, The object of the science is that of which it principally treats. But in this science, the treatment is mainly about God; for it is called theology, as treating of God. Therefore God is the object of this science.
I answer that, God is the object of this science. The relation between a science and its object is the same as that between a habit or faculty and its object. Now properly speaking, the object of a faculty or habit is the thing under the aspect of which all things are referred to that faculty or habit, as man and stone are referred to the faculty of sight in that they are colored. Hence colored things are the proper objects of sight. But in sacred science, all things are treated of under the aspect of God: either because they are God Himself or because they refer to God as their beginning and end. Hence it follows that God is in very truth the object of this science. This is clear also from the principles of this science, namely, the articles of faith, for faith is about God. The object of the principles and of the whole science must be the same, since the whole science is contained virtually in its principles. Some, however, looking to what is treated of in this science, and not to the aspect under which it is treated, have asserted the object of this science to be something other than God---that is, either things and signs; or the works of salvation; or the whole Christ, as the head and members. Of all these things, in truth, we treat in this science, but so far as they have reference to God.
Reply to Objection 1: Although we cannot know in what consists the essence of God, nevertheless in this science we make use of His effects, either of nature or of grace, in place of a definition, in regard to whatever is treated of in this science concerning God; even as in some philosophical sciences we demonstrate something about a cause from its effect, by taking the effect in place of a definition of the cause.
Reply to Objection 2: Whatever other conclusions are reached in this sacred science are comprehended under God, not as parts or species or accidents but as in some way related to Him.
Art. 8 - Whether sacred doctrine is a matter of argument?
Objection 1: It seems this doctrine is not a matter of argument. For Ambrose says (De Fide 1): "Put arguments aside where faith is sought." But in this doctrine, faith especially is sought: "But these things are written that you may believe" (Jn. 20:31). Therefore sacred doctrine is not a matter of argument.
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."
Art. 9 - 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 whatsoever we may say or think of Him. Thirdly, because thereby divine truths are the better hidden from the unworthy.
Art. 10 - Whether in Holy Scripture a word may have several senses?
Objection 1: It seems that in Holy Writ a word cannot have several senses, historical or literal, allegorical, tropological or moral, and anagogical. For many different senses in one text produce confusion and deception and destroy all force of argument. Hence no argument, but only fallacies, can be deduced from a multiplicity of propositions. But Holy Writ ought to be able to state the truth without any fallacy. Therefore in it there cannot be several senses to a word.
Objection 2: Further, Augustine says (De util. cred. iii) that "the Old Testament has a fourfold division as to history, etiology, analogy and allegory." Now these four seem altogether different from the four divisions mentioned in the first objection. Therefore it does not seem fitting to explain the same word of Holy Writ according to the four different senses mentioned above.
Objection 3: Further, besides these senses, there is the parabolical, which is not one of these four.
On the contrary, Gregory says (Moral. xx, 1): "Holy Writ by the manner of its speech transcends every science, because in one and the same sentence, while it describes a fact, it reveals a mystery."
I answer that, The author of Holy Writ is God, in whose power it is to signify His meaning, not by words only (as man also can do), but also by things themselves. So, whereas in every other science things are signified by words, this science has the property, that the things signified by the words have themselves also a signification. Therefore that first signification whereby words signify things belongs to the first sense, the historical or literal. That signification whereby things signified by words have themselves also a signification is called the spiritual sense, which is based on the literal, and presupposes it. Now this spiritual sense has a threefold division. For as the Apostle says (Heb. 10:1) the Old Law is a figure of the New Law, and Dionysius says (Coel. Hier. i) "the New Law itself is a figure of future glory." Again, in the New Law, whatever our Head has done is a type of what we ought to do. Therefore, so far as the things of the Old Law signify the things of the New Law, there is the allegorical sense; so far as the things done in Christ, or so far as the things which signify Christ, are types of what we ought to do, there is the moral sense. But so far as they signify what relates to eternal glory, there is the anagogical sense. Since the literal sense is that which the author intends, and since the author of Holy Writ is God, Who by one act comprehends all things by His intellect, it is not unfitting, as Augustine says (Confess. xii), if, even according to the literal sense, one word in Holy Writ should have several senses.
Reply to Objection 1: The multiplicity of these senses does not produce equivocation or any other kind of multiplicity, seeing that these senses are not multiplied because one word signifies several things, but because the things signified by the words can be themselves types of other things. Thus in Holy Writ no confusion results, for all the senses are founded on one---the literal---from which alone can any argument be drawn, and not from those intended in allegory, as Augustine says (Epis. 48). Nevertheless, nothing of Holy Scripture perishes on account of this, since nothing necessary to faith is contained under the spiritual sense which is not elsewhere put forward by the Scripture in its literal sense.
Reply to Objection 2: These three---history, etiology, analogy---are grouped under the literal sense. For it is called history, as Augustine expounds (Epis. 48), whenever anything is simply related; it is called etiology when its cause is assigned, as when Our Lord gave the reason why Moses allowed the putting away of wives---namely, on account of the hardness of men's hearts; it is called analogy whenever the truth of one text of Scripture is shown not to contradict the truth of another. Of these four, allegory alone stands for the three spiritual senses. Thus Hugh of St. Victor (Sacram. iv, 4 Prolog.) includes the anagogical under the allegorical sense, laying down three senses only---the historical, the allegorical, and the tropological.
Reply to Objection 3: The parabolical sense is contained in the literal, for by words things are signified properly and figuratively. Nor is the figure itself, but that which is figured, the literal sense. When Scripture speaks of God's arm, the literal sense is not that God has such a member, but only what is signified by this member, namely operative power. Hence it is plain that nothing false can ever underlie the literal sense of Holy Writ.