Objection 1. It would seem that a religious order which is devoted to the contemplative life is not more excellent than one which is given to the active life. For it is said (Extra, de Regular. et Transeunt. ad Relig., cap. Licet), quoting the words of Innocent III: "Even as a greater good is preferred to a lesser, so the common profit takes precedence of private profit: and in this case teaching is rightly preferred to silence, responsibility to contemplation, work to rest." Now the religious order which is directed to the greater good is better. Therefore it would seem that those religious orders that are directed to the active life are more excellent than those which are directed to the contemplative life.
Objection 2. Further, every religious order is directed to the perfection of charity, as stated above (1 and 2). Now a gloss on Hebrews 12:4, "For you have not yet resisted unto blood," says: "In this life there is no more perfect love than that to which the holy martyrs attained, who fought against sin unto blood." Now to fight unto blood is becoming those religious who are directed to military service, and yet this pertains to the active life. Therefore it would seem that religious orders of this kind are the most excellent.
Objection 3. Further, seemingly the stricter a religious order is, the more excellent it is. But there is no reason why certain religious orders directed to the active life should not be of stricter observance than those directed to the contemplative life. Therefore they are more excellent.
On the contrary, our Lord said (Luke 10:42) that the "best part" was Mary's, by whom the contemplative life is signified.
I answer that, As stated above (Article 1), the difference between one religious order and another depends chiefly on the end, and secondarily on the exercise. And since one thing cannot be said to be more excellent than another save in respect of that in which it differs therefrom, it follows that the excellence of one religious order over another depends chiefly on their ends, and secondarily on their respective exercises. Nevertheless each of these comparisons is considered in a different way. For the comparison with respect to the end is absolute, since the end is sought for its own sake; whereas the comparison with respect to exercise is relative, since exercise is sought not for its own sake, but for the sake of the end. Hence a religious order is preferable to another, if it be directed to an end that is absolutely more excellent either because it is a greater good or because it is directed to more goods. If, however, the end be the same, the excellence of one religious order over another depends secondarily, not on the amount of exercise, but on the proportion of the exercise to the end in view. Wherefore in the Conferences of the Fathers (Coll. ii, 2) Blessed Antony is quoted, as preferring discretion whereby a man moderates all his actions, to fastings, watchings, and all such observances.
Accordingly we must say that the work of the active life is twofold. one proceeds from the fulness of contemplation, such as teaching and preaching. Wherefore Gregory says (Hom. v in Ezech.) that the words of Psalm 144:7, "They shall publish the memory of... Thy sweetness," refer "to perfect men returning from their contemplation." And this work is more excellent than simple contemplation. For even as it is better to enlighten than merely to shine, so is it better to give to others the fruits of one's contemplation than merely to contemplate. The other work of the active life consists entirely in outward occupation, for instance almsgiving, receiving guests, and the like, which are less excellent than the works of contemplation, except in cases of necessity, as stated above (Question 182, Article 1). Accordingly the highest place in religious orders is held by those which are directed to teaching and preaching, which, moreover, are nearest to the episcopal perfection, even as in other things "the end of that which is first is in conjunction with the beginning of that which is second," as Dionysius states (Div. Nom. vii). The second place belongs to those which are directed to contemplation, and the third to those which are occupied with external actions.
Moreover, in each of these degrees it may be noted that one religious order excels another through being directed to higher action in the same genus; thus among the works of the active life it is better to ransom captives than to receive guests, and among the works of the contemplative life prayer is better than study. Again one will excel another if it be directed to more of these actions than another, or if it have statutes more adapted to the attainment of the end in view.
Reply to Objection 1. This Decretal refers to the active life as directed to the salvation of souls.
Reply to Objection 2. Those religious orders that are established for the purpose of military service aim more directly at shedding the enemy's blood than at the shedding of their own, which latter is more properly competent to martyrs. Yet there is no reason why religious of this description should not acquire the merit of martyrdom in certain cases, and in this respect stand higher than other religious; even as in some cases the works of the active life take precedence of contemplation.
Reply to Objection 3. Strictness of observances, as the Blessed Antony remarks (Conferences of the Fathers; Coll. ii, 2), is not the chief object of commendation in a religious order; and it is written (Isaiah 58:5): "Is this such a fast as I have chosen, for a man to afflict his soul for a day?" Nevertheless it is adopted in religious life as being necessary for taming the flesh, "which if done without discretion, is liable to make us fail altogether," as the Blessed Antony observes. Wherefore a religious order is not more excellent through having stricter observances, but because its observances are directed by greater discretion to the end of religion. Thus the taming of the flesh is more efficaciously directed to continence by means of abstinence in meat and drink, which pertain to hunger and thirst, than by the privation of clothing, which pertains to cold and nakedness, or by bodily labor.
Source: Summa Theologica (New Advent)