Objection 1. It would seem that a religious order should not be established for the purpose of study. For it is written (Psalm 70:15-16): "Because I have not known letters [Douay: 'learning'], I will enter into the powers of the Lord," i.e. "Christian virtue," according to a gloss. Now the perfection of Christian virtue, seemingly, pertains especially to religious. Therefore it is not for them to apply themselves to the study of letters.
Objection 2. Further, that which is a source of dissent is unbecoming to religious, who are gathered together in the unity of peace. Now study leads to dissent: wherefore different schools of thought arose among the philosophers. Hence Jerome (Super Epist. ad Tit. 1:5) says: "Before a diabolical instinct brought study into religion, and people said: I am of Paul, I of Apollo, I of Cephas," etc. Therefore it would seem that no religious order should be established for the purpose of study.
Objection 3. Further, those who profess the Christian religion should profess nothing in common with the Gentiles. Now among the Gentiles were some who professed philosophy, and even now some secular persons are known as professors of certain sciences. Therefore the study of letters does not become religious.
On the contrary, Jerome (Ep. liii ad Paulin.) urges him to acquire learning in the monastic state, saying: "Let us learn on earth those things the knowledge of which will remain in heaven," and further on: "Whatever you seek to know, I will endeavor to know with you."
I answer that As stated above (Article 2), religion may be ordained to the active and to the contemplative life. Now chief among the works of the active life are those which are directly ordained to the salvation of souls, such as preaching and the like. Accordingly the study of letters is becoming to the religious life in three ways. First, as regards that which is proper to the contemplative life, to which the study of letters helps in a twofold manner. On one way by helping directly to contemplate, namely by enlightening the intellect. For the contemplative life of which we are now speaking is directed chiefly to the consideration of divine things, as stated above (Question 180, Article 4), to which consideration man is directed by study; for which reason it is said in praise of the righteous (Psalm 1:2) that "he shall meditate day and night" on the law of the Lord, and (Sirach 39:1): "The wise man will seek out the wisdom of all the ancients, and will be occupied in the prophets." On another way the study of letters is a help to the contemplative life indirectly, by removing the obstacles to contemplation, namely the errors which in the contemplation of divine things frequently beset those who are ignorant of the scriptures. Thus we read in the Conferences of the Fathers (Coll. x, 3) that the Abbot Serapion through simplicity fell into the error of the Anthropomorphites, who thought that God had a human shape. Hence Gregory says (Moral. vi) that "some through seeking in contemplation more than they are able to grasp, fall away into perverse doctrines, and by failing to be the humble disciples of truth become the masters of error." Hence it is written (Ecclesiastes 2:3): "I thought in my heart to withdraw my flesh from wine, that I might turn my mind to wisdom and might avoid folly."
Secondly, the study of letters is necessary in those religious orders that are founded for preaching and other like works; wherefore the Apostle (Titus 1:9), speaking of bishops to whose office these acts belong, says: "Embracing that faithful word which is according to doctrine, that he may be able to exhort in sound doctrine and to convince the gainsayers." Nor does it matter that the apostles were sent to preach without having studied letters, because, as Jerome says (Ep. liii ad Paulin.), "whatever others acquire by exercise and daily meditation in God's law, was taught them by the Holy Ghost."
Thirdly, the study of letters is becoming to religious as regards that which is common to all religious orders. For it helps us to avoid the lusts of the flesh; wherefore Jerome says (Ep. cxxv ad Rust. Monach.): "Love the science of the Scriptures and thou shalt have no love for carnal vice." For it turns the mind away from lustful thoughts, and tames the flesh on account of the toil that study entails according to Sirach 31:1, "Watching for riches* consumeth the flesh." [Vigilia honestatis St. Thomas would seem to have taken 'honestas' in the sense of virtue]. It also helps to remove the desire of riches, wherefore it is written (Wisdom 7:8): "I... esteemed riches nothing in comparison with her," and (1 Maccabees 12:9): "We needed none of these things," namely assistance from without, "having for our comfort the holy books that are in our hands." It also helps to teach obedience, wherefore Augustine says (De oper. Monach. xvii): "What sort of perverseness is this, to wish to read, but not to obey what one reads?" Hence it is clearly fitting that a religious order be established for the study of letters.
Reply to Objection 1. This commentary of the gloss is an exposition of the Old Law of which the Apostle says (2 Corinthians 3:6): "The letter killeth." Hence not to know letters is to disapprove of the circumcision of the "letter" and other carnal observances.
Reply to Objection 2. Study is directed to knowledge which, without charity, "puffeth up," and consequently leads to dissent, according to (Proverbs 13:10), "Among the proud there are always dissensions": whereas, with charity, it "edifieth and begets concord." Hence the Apostle after saying (1 Corinthians 1:5): "You are made rich... in all utterance and in all knowledge," adds (1 Corinthians 1:10): "That you all speak the same thing, and that there be no schisms among you." But Jerome is not speaking here of the study of letters, but of the study of dissensions which heretics and schismatics have brought into the Christian religion.
Reply to Objection 3. The philosophers professed the study of letters in the matter of secular learning: whereas it becomes religious to devote themselves chiefly to the study of letters in reference to the doctrine that is "according to godliness" (Titus 1:1). It becomes not religious, whose whole life is devoted to the service of God, to seek for other learning, save in so far as it is referred to the sacred doctrine. Hence Augustine says at the end of De Musica vi, 17: "Whilst we think that we should not overlook those whom heretics delude by the deceitful assurance of reason and knowledge, we are slow to advance in the consideration of their methods. Yet we should not be praised for doing this, were it not that many holy sons of their most loving mother the Catholic Church had done the same under the necessity of confounding heretics."
Source: Summa Theologica (New Advent)