Objection 1. It would seem that the religious life of those who live in community is more perfect than that of those who lead a solitary life. For it is written (Ecclesiastes 4:9): "It is better... that two should be together, than one; for they have the advantage of their society." Therefore the religious life of those who live in community would seem to be more perfect.
Objection 2. Further, it is written (Matthew 18:20): "Where there are two or three gathered together in My name, there am I in the midst of them." But nothing can be better than the fellowship of Christ. Therefore it would seem better to live in community than in solitude.
Objection 3. Further, the vow of obedience is more excellent than the other religious vows; and humility is most acceptable to God. Now obedience and humility are better observed in company than in solitude; for Jerome says (Ep. cxxv ad Rustic. Monach.): "In solitude pride quickly takes man unawares, he sleeps as much as he will, he does what he likes"; whereas when instructing one who lives in community, he says: "You may not do what you will, you must eat what you are bidden to eat, you may possess so much as you receive, you must obey one you prefer not to obey, you must be a servant to your brethren, you must fear the superior of the monastery as God, love him as a father." Therefore it would seem that the religious life of those who live in community is more perfect than that of those who lead a solitary life.
Objection 4. Further, our Lord said (Luke 11:3)3): "No man lighteth a candle and putteth it in a hidden place, nor under a bushel." Now those who lead a solitary life are seemingly in a hidden place, and to be doing no good to any man. Therefore it would seem that their religious life is not more perfect.
Objection 5. Further, that which is in accord with man's nature is apparently more pertinent to the perfection of virtue. But man is naturally a social animal, as the Philosopher says (Polit. i, 1). Therefore it would seem that to lead a solitary life is not more perfect than to lead a community life.
On the contrary, Augustine says (De oper. Monach. xxiii) that "those are holier who keep themselves aloof from the approach of all, and give their whole mind to a life of prayer."
I answer that, Solitude, like poverty, is not the essence of perfection, but a means thereto. Hence in the Conferences of the Fathers (Coll. i, 7) the Abbot Moses says that "solitude," even as fasting and other like things, is "a sure means of acquiring purity of heart." Now it is evident that solitude is a means adapted not to action but to contemplation, according to Hosea 2:14, "I... will lead her into solitude [Douay: 'the wilderness']; and I will speak to her heart." Wherefore it is not suitable to those religious orders that are directed to the works whether corporal or spiritual of the active life; except perhaps for a time, after the example of Christ, Who as Luke relates (6:12), "went out into a mountain to pray; and He passed the whole night in the prayer of God." On the other hand, it is suitable to those religious orders that are directed to contemplation.
It must, however, be observed that what is solitary should be self-sufficing by itself. Now such a thing is one "that lacks nothing," and this belongs to the idea of a perfect thing [Aristotle, Phys. iii, 6]. Wherefore solitude befits the contemplative who has already attained to perfection. This happens in two ways: in one way by the gift only of God, as in the case of John the Baptist, who was "filled with the Holy Ghost even from his mother's womb" (Luke 1:11), so that he was in the desert even as a boy; in another way by the practice of virtuous action, according to (Hebrews 5:1)4: "Strong meat is for the perfect; for them who by custom have their senses exercised to the discerning of good and evil."
Now man is assisted in this practice by the fellowship of others in two ways. First, as regards his intellect, to the effect of his being instructed in that which he has to contemplate; wherefore Jerome says (ad Rustic. Monach., Ep. cxxv): "It pleases me that you have the fellowship of holy men, and teach not yourself. Secondly, as regards the affections, seeing that man's noisome affections are restrained by the example and reproof which he receives from others; for as Gregory says (Moral. xxx, 23), commenting on the words, "To whom I have given a house in the wilderness" (Job 39:6), "What profits solitude of the body, if solitude of the heart be lacking?" Hence a social life is necessary for the practice of perfection. Now solitude befits those who are already perfect; wherefore Jerome says (ad Rustic. Monach., Ep. cxxv): "Far from condemning the solitary life, we have often commended it. But we wish the soldiers who pass from the monastic school to be such as not to be deterred by the hard noviciate of the desert, and such as have given proof of their conduct for a considerable time.
Accordingly, just as that which is already perfect surpasses that which is being schooled in perfection, so the life of the solitaries, if duly practiced, surpasses the community life. But if it be undertaken without the aforesaid practice, it is fraught with very great danger, unless the grace of God supply that which others acquire by practice, as in the case of the Blessed Antony and the Blessed Benedict.
Reply to Objection 1. Solomon shows that two are better than one, on account of the help which one affords the other either by "lifting him" up, or by "warming him," i.e. giving him spiritual heat (Ecclesiastes 4:10-11). But those who have already attained to perfection do not require this help.
Reply to Objection 2. According to (1 John 4:16), "He that abideth in charity abideth in God and God in him." Wherefore just as Christ is in the midst of those who are united together in the fellowship of brotherly love, so does He dwell in the heart of the man who devotes himself to divine contemplation through love of God.
Reply to Objection 3. Actual obedience is required of those who need to be schooled according to the direction of others in the attainment of perfection; but those who are already perfect are sufficiently "led by the spirit of God" so that they need not to obey others actually. Nevertheless they have obedience in the preparedness of the mind.
Reply to Objection 4. As Augustine says (De Civ. Dei xix, 19), "no one is forbidden to seek the knowledge of truth, for this pertains to a praiseworthy leisure." That a man be placed "on a candlestick," does not concern him but his superiors, and "if this burden is not placed on us," as Augustine goes on to say (De Civ. Dei xix, 19), "we must devote ourselves to the contemplation of truth," for which purpose solitude is most helpful. Nevertheless, those who lead a solitary life are most useful to mankind. Hence, referring to them, Augustine says (De Morib. Eccl. xxxi): "They dwell in the most lonely places, content to live on water and the bread that is brought to them from time to time, enjoying colloquy with God to whom they have adhered with a pure mind. To some they seem to have renounced human intercourse more than is right: but these understand not how much such men profit us by the spirit of their prayers, what an example to us is the life of those whom we are forbidden to see in the body."
Reply to Objection 5. A man may lead a solitary life for two motives. one is because he is unable, as it were, to bear with human fellowship on account of his uncouthness of mind; and this is beast-like. The other is with a view to adhering wholly to divine things; and this is superhuman. Hence the Philosopher says (Polit. i, 1) that "he who associates not with others is either a beast or a god," i.e. a godly man.
Source: Summa Theologica (New Advent)