Human solicitude busies itself about the common measure of human life in three chief particulars. First, about one's own person, what one is to do or where to live; secondly, about persons related to oneself, especially wife and children; thirdly, about the procurement of exterior things, needful for the support of life. For cutting off solicitude about exterior things there is given in the divine law the counsel of poverty, which prompts to the casting away of the things of this world. Hence the Lord says: If thou wilt be perfect, go, sell what thou hast and give to the poor, and come, follow me (Matt. xix, 21). For cutting off solicitude about wife and children there is given man the counsel of virginity, or continence. Hence it is said: About virgins I have no commandment of the Lord, but I give a counsel; and, adding the reason of this counsel, he continues: He that is without a wife is solicitous for the things of the Lord, how he may please God; but he that is with a wife is solicitous for the things of the world, how he may please his wife, and is divided (1 Cor. vii, 25-33). For cutting off man's solicitude even about himself there is given the counsel of obedience, whereby a man commits the disposal of his acts to his superior. Therefore it is said: Obey your superiors and be subject to them, for they watch as having to render an account of your souls (Heb. xiii, 17).
Because the highest perfection of human life consists in the mind of man being detached from other things and fixed on God, and the three counsels aforesaid seem singularly to dispose the mind to this detachment, we may see in them proper adjuncts of a state of perfection, not that they themselves constitute perfection, but inasmuch as they are dispositions to perfection, which consists in the union of the detached soul with God. This is expressly shown in the words of our Lord counselling poverty: If thou wilt be perfect, go, sell what thou hast, and give to the poor, and follow me, -- where He places the perfection of life in the following of Him.
They may also be called effects and signs of perfection. For when the mind is strongly possessed with love and desire of anything, it thereupon counts other things as quite secondary: so from man's mind being carried with fervent love and desire to divine things, wherein its perfection consists, the consequence is a casting off of all that might retard its movement to God, -- care of property, affection for wife and children, and even love of one's own self. This is signified by the words of Scripture: If a man shall give the whole substance of his house in exchange for love, he will account it nothing (Cant. viii, 7): Having found one precious pearl, he went and sold all that he had, and acquired it (Matt. xiii, 46): the advantages that I had I considered as dirt, that I might gain Christ (Philip. iii, 8).
Since then the three counsels aforesaid are dispositions to perfection, and effects of perfection, and signs of the same, they who make the three corresponding vows to God are properly said to be in a state of perfection. The perfection to which they dispose the mind consists in the free converse of the soul with God. Hence they who make profession of the aforesaid vows are called 'religious,' as dedicating themselves and all that is theirs to God by a manner of sacrifice, extending to property by poverty, to the body by continence, and to the will by obedience: for religion consists in the worship of God (Chap. CXIX).
3.130 : That the Divine Government of Men is after the manner of Paternal Government
3.132, 135 : Arguments against Voluntary Poverty, with Replies