Thomas Aquinas
Summa Theoligica

Original Electronic Text at the New Advent Catholic web site.

First Part
Question 1
The nature and extent of sacred doctrine
Article 1
Whether, besides philosophy, any further doctrine is required?

Objection 1. 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" (Sirach 3:22). But whatever is not above reason is fully treated of in philosophical science. Therefore any other knowledge besides philosophical science is superfluous.

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. 66:4). 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" (Sirach 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.

Question 1
Article 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."

First Part of the Second Part
Question 55
Article 4 Whether virtue is suitably defined?

Objection 1. It would seem that the definition, usually given, of virtue, is not suitable, to wit: "Virtue is a good quality of the mind, by which we live righteously, of which no one can make bad use, which God works in us, without us." For virtue is man's goodness, since virtue it is that makes its subject good. But goodness does not seem to be good, as neither is whiteness white. It is therefore unsuitable to describe virtue as a "good quality."

Objection 2. Further, no difference is more common than its genus; since it is that which divides the genus. But good is more common than quality, since it is convertible with being. Therefore "good" should not be put in the definition of virtue, as a difference of quality.

Objection 3. Further, as Augustine says (De Trin. xii, 3): "When we come across anything that is not common to us and the beasts of the field, it is something appertaining to the mind." But there are virtues even of the irrational parts; as the Philosopher says (Ethic. iii, 10). Every virtue, therefore, is not a good quality "of the mind."

Objection 4. Further, righteousness seems to belong to justice; whence the righteous are called just. But justice is a species of virtue. It is therefore unsuitable to put "righteous" in the definition of virtue, when we say that virtue is that "by which we live righteously."

Objection 5. Further, whoever is proud of a thing, makes bad use of it. But many are proud of virtue, for Augustine says in his Rule, that "pride lies in wait for good works in order to slay them." It is untrue, therefore, "that no one can make bad use of virtue."

Objection 6. Further, man is justified by virtue. But Augustine commenting on Jn. 15:11: "He shall do greater things than these," says [Tract. xxvii in Joan.: Serm. xv de Verb. Ap. 11: "He who created thee without thee, will not justify thee without thee." It is therefore unsuitable to say that "God works virtue in us, without us."

On the contrary, We have the authority of Augustine from whose words this definition is gathered, and principally in De Libero Arbitrio ii, 19.

I answer that, This definition comprises perfectly the whole essential notion of virtue. For the perfect essential notion of anything is gathered from all its causes. Now the above definition comprises all the causes of virtue. For the formal cause of virtue, as of everything, is gathered from its genus and difference, when it is defined as "a good quality": for "quality" is the genus of virtue, and the difference, "good." But the definition would be more suitable if for "quality" we substitute "habit," which is the proximate genus.

Now virtue has no matter "out of which" it is formed, as neither has any other accident; but it has matter "about which" it is concerned, and matter "in which" it exits, namely, the subject. The matter about which virtue is concerned is its object, and this could not be included in the above definition, because the object fixes the virtue to a certain species, and here we are giving the definition of virtue in general. And so for material cause we have the subject, which is mentioned when we say that virtue is a good quality "of the mind."

The end of virtue, since it is an operative habit, is operation. But it must be observed that some operative habits are always referred to evil, as vicious habits: others are sometimes referred to good, sometimes to evil; for instance, opinion is referred both to the true and to the untrue: whereas virtue is a habit which is always referred to good: and so the distinction of virtue from those habits which are always referred to evil, is expressed in the words "by which we live righteously": and its distinction from those habits which are sometimes directed unto good, sometimes unto evil, in the words, "of which no one makes bad use."

Lastly, God is the efficient cause of infused virtue, to which this definition applies; and this is expressed in the words "which God works in us without us." If we omit this phrase, the remainder of the definition will apply to all virtues in general, whether acquired or infused.

Reply to Objection 1. That which is first seized by the intellect is being: wherefore everything that we apprehend we consider as being, and consequently as gone, and as good, which are convertible with being. Wherefore we say that essence is being and is one and is good; and that oneness is being and one and good: and in like manner goodness. But this is not the case with specific forms, as whiteness and health; for everything that we apprehend, is not apprehended with the notion of white and healthy. We must, however, observe that, as accidents and non-subsistent forms are called beings, not as if they themselves had being, but because things are by them; so also are they called good or one, not by some distinct goodness or oneness, but because by them something is good or one. So also is virtue called good, because by it something is good.

Reply to Objection 2. Good, which is put in the definition of virtue, is not good in general which is convertible with being, and which extends further than quality, but the good as fixed by reason, with regard to which Dionysius says (Div. Nom. iv) "that the good of the soul is to be in accord with reason."

Reply to Objection 3. Virtue cannot be in the irrational part of the soul, except in so far as this participates in the reason (Ethic. i, 13). And therefore reason, or the mind, is the proper subject of virtue.

Reply to Objection 4. Justice has a righteousness of its own by which it puts those outward things right which come into human use, and are the proper matter of justice, as we shall show further on (60, 2; II-II, 58, 8). But the righteousness which denotes order to a due end and to the Divine law, which is the rule of the human will, as stated above (19, 4), is common to all virtues.

Reply to Objection 5. One can make bad use of a virtue objectively, for instance by having evil thoughts about a virtue, e.g. by hating it, or by being proud of it: but one cannot make bad use of virtue as principle of action, so that an act of virtue be evil.

Reply to Objection 6. Infused virtue is caused in us by God without any action on our part, but not without our consent. This is the sense of the words, "which God works in us without us." As to those things which are done by us, God causes them in us, yet not without action on our part, for He works in every will and in every nature.

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