Summa Theologica I-II, q. 102: Of the Causes of the Ceremonial Precepts
Article 6. Whether there was any reasonable cause for the ceremonial observances?
Objection 1It would seem that there was no reasonable cause for the ceremonial observances. Because, as the Apostle says (1 Tim. 4:4), "every creature of God is good, and nothing to be rejected that is received with thanksgiving." It was therefore unfitting that they should be forbidden to eat certain foods, as being unclean according to Lev. 11 [*Cf. Dt. 14].
Objection 2Further, just as animals are given to man for food, so also are herbs: wherefore it is written (Gn. 9:3): "As the green herbs have I delivered all" flesh "to you." But the Law did not distinguish any herbs from the rest as being unclean, although some are most harmful, for instance, those that are poisonous. Therefore it seems that neither should any animals have been prohibited as being unclean.
Objection 3Further, if the matter from which a thing is generated be unclean, it seems that likewise the thing generated therefrom is unclean. But flesh is generated from blood. Since therefore all flesh was not prohibited as unclean, it seems that in like manner neither should blood have been forbidden as unclean; nor the fat which is engendered from blood.
Objection 4Further, Our Lord said (Mat. 10:28; cf. Lk. 12:4), that those should not be feared "that kill the body," since after death they "have no more that they can do": which would not be true if after death harm might come to man through anything done with his body. Much less therefore does it matter to an animal already dead how its flesh be cooked. Consequently there seems to be no reason in what is said, Ex. 23:19: "Thou shalt not boil a kid in the milk of its dam."
Objection 5Further, all that is first brought forth of man and beast, as being most perfect, is commanded to be offered to the Lord (Ex. 13). Therefore it is an unfitting command that is set forth in Lev. 19:23: "when you shall be come into the land, and shall have planted in it fruit trees, you shall take away the uncircumcision [*'Praeputia,' which Douay version renders 'first fruits'] of them," i.e. the first crops, and they "shall be unclean to you, neither shall you eat of them."
Objection 6Further, clothing is something extraneous to man's body. Therefore certain kinds of garments should not have been forbidden to the Jews: for instance (Lev. 19:19): "Thou shalt not wear a garment that is woven of two sorts": and (Dt. 22:5): "A woman shall not be clothed with man's apparel, neither shall a man use woman's apparel": and further on (Dt. 22:11): "Thou shalt not wear a garment that is woven of woolen and linen together."
Objection 7Further, to be mindful of God's commandments concerns not the body but the heart. Therefore it is unsuitably prescribed (Dt. 6:8, seqq.) that they should "bind" the commandments of God "as a sign" on their hands; and that they should "write them in the entry"; and (Num. 15:38, seqq.) that they should "make to themselves fringes in the corners of their garments, putting in them ribands of blue. . . they may remember. . . the commandments of the Lord."
Objection 8Further, the Apostle says (1 Cor. 9:9) that God does not "take care for oxen," and, therefore, neither of other irrational animals. Therefore without reason is it commanded (Dt. 22:6): "If thou find, as thou walkest by the way, a bird's nest in a tree. . . thou shalt not take the dam with her young"; and (Dt. 25:4): "Thou shalt not muzzle the ox that treadeth out thy corn"; and (Lev. 19:19): "Thou shalt not make thy cattle to gender with beasts of any other kind."
Objection 9Further, no distinction was made between clean and unclean plants. Much less therefore should any distinction have been made about the cultivation of plants. Therefore it was unfittingly prescribed (Lev. 19:19): "Thou shalt not sow thy field with different seeds"; and (Dt. 22:9, seqq.): "Thou shalt not sow thy vineyard with divers seeds"; and: "Thou shalt not plough with an ox and an ass together."
Objection 10Further, it is apparent that inanimate things are most of all subject to the power of man. Therefore it was unfitting to debar man from taking silver and gold of which idols were made, or anything they found in the houses of idols, as expressed in the commandment of the Law (Dt. 7:25, seqq.). It also seems an absurd commandment set forth in Dt. 23:13, that they should "dig round about and. . . cover with earth that which they were eased of."
Objection 11Further, piety is required especially in priests. But it seems to be an act of piety to assist at the burial of one's friends: wherefore Tobias is commended for so doing (Tob. 1:20, seqq.). In like manner it is sometimes an act of piety to marry a loose woman, because she is thereby delivered from sin and infamy. Therefore it seems inconsistent for these things to be forbidden to priests (Lev. 21).
On the contraryIt is written (Dt. 18:14): "But thou art otherwise instructed by the Lord thy God": from which words we may gather that these observances were instituted by God to be a special prerogative of that people. Therefore they are not without reason or cause.
I answer thatThe Jewish people, as stated above (A[5]), were specially chosen for the worship of God, and among them the priests themselves were specially set apart for that purpose. And just as other things that are applied to the divine worship, need to be marked in some particular way so that they be worthy of the worship of God; so too in that people's, and especially the priests', mode of life, there needed to be certain special things befitting the divine worship, whether spiritual or corporal. Now the worship prescribed by the Law foreshadowed the mystery of Christ: so that whatever they did was a figure of things pertaining to Christ, according to 1 Cor. 10:11: "All these things happened to them in figures." Consequently the reasons for these observances may be taken in two ways, first according to their fittingness to the worship of God; secondly, according as they foreshadow something touching the Christian mode of life.
Reply to Objection 1As stated above (A[5], ad 4,5), the Law distinguished a twofold pollution or uncleanness; one, that of sin, whereby the soul was defiled; and another consisting in some kind of corruption, whereby the body was in some way infected. Speaking then of the first-mentioned uncleanness, no kind of food is unclean, or can defile a man, by reason of its nature; wherefore we read (Mat. 15:11): "Not that which goeth into the mouth defileth a man; but what cometh out of the mouth, this defileth a man": which words are explained (Mat. 15:17) as referring to sins. Yet certain foods can defile the soul accidentally; in so far as man partakes of them against obedience or a vow, or from excessive concupiscence; or through their being an incentive to lust, for which reason some refrain from wine and flesh-meat.