Summa Theologiae > Second Part of the Second Part > Question 182: Article 1.
Nothing prevents certain things being more excellent in themselves, whereas they are surpassed by another in some respect. Accordingly, we must reply that the contemplative life is simply more excellent than the active: and the Philosopher proves this by eight reasons (Ethic. x, 7,8). The first is, because the contemplative life becomes man according to that which is best in him, namely the intellect, and according to its proper objects, namely things intelligible; whereas the active life is occupied with externals. Hence Rachael, by whom the contemplative life is signified, is interpreted "the vision of the principle," [Or rather, 'One seeing the principle,' if derived from rah and irzn; Cf. Jerome, De Nom. Hebr.] whereas as Gregory says (Moral. vi, 37) the active life is signified by Lia who was blear-eyed. The second reason is because the contemplative life can be more continuous, although not as regards the highest degree of contemplation, as stated above (II-II:180:8 ad 2; II-II:181:4 ad 3), wherefore Mary, by whom the contemplative life is signified, is described as "sitting" all the time "at the Lord's feet." Thirdly, because the contemplative life is more delightful than the active; wherefore Augustine says (De Verb. Dom. Serm. ciii) that "Martha was troubled, but Mary feasted." Fourthly, because in the contemplative life man is more self-sufficient, since he needs fewer things for that purpose; wherefore it was said (Luke 10:41): "Martha, Martha, thou art careful and art troubled about many things." Fifthly, because the contemplative life is loved more for its own sake, while the active life is directed to something else. Hence it is written (Psalm 36:4): "One thing I have asked of the Lord, this will I seek after, that I may dwell in the house of the Lord all the days of my life, that I may see the delight of the Lord." Sixthly, because the contemplative life consists in leisure and rest, according to Psalm 45:11, "Be still and see that I am God." Seventhly, because the contemplative life is according to Divine things, whereas active life is according to human things; wherefore Augustine says (De Verb. Dom. Serm. civ): "'In the beginning was the Word': to Him was Mary hearkening: 'The Word was made flesh': Him was Martha serving." Eighthly, because the contemplative life is according to that which is most proper to man, namely his intellect; whereas in the works of the active life the lower powers also, which are common to us and brutes, have their part; wherefore (Psalm 35:7) after the words, "Men and beasts Thou wilt preserve, O Lord," that which is special to man is added (Psalm 35:10): "In Thy light we shall see light."
Our Lord adds a ninth reason (Luke 10:42) when He says: "Mary hath chosen the best part, which shall not be taken away from her," which words Augustine (De Verb. Dom. Serm. ciii) expounds thus: "Not—Thou hast chosen badly but—She has chosen better. Why better? Listen—because it shall not be taken away from her. But the burden of necessity shall at length be taken from thee: whereas the sweetness of truth is eternal."
\Yet in a restricted sense and in a particular case one should prefer the active life on account of the needs of the present life. Thus too the Philosopher says (Topic. iii, 2): "It is better to be wise than to be rich, yet for one who is in need, it is better to be rich . . ."