Q: Whether the Ceremonies of the Law Were in Existence Before the Law?

A: On the contrary,
It is written (Deut. 6:1): "These are the precepts and ceremonies . . . which the Lord your God commanded that I should teach you." But they would not have needed to be taught about these things, if the aforesaid ceremonies had been already in existence. Therefore the legal ceremonies did not precede the Law.

I answer that,
As is clear from what has been said (Q. 101, A. 2; Q. 102, A. 2), the legal ceremonies were ordained for a double purpose; the worship of God, and the foreshadowing of Christ. Now whoever worships God must needs worship Him by means of certain fixed things pertaining to external worship. But the fixing of the divine worship belongs to the ceremonies; just as the determining of our relations with our neighbor is a matter determined by the judicial precepts, as stated above (Q. 99, A. 4). Consequently, as among men in general there were certain judicial precepts, not indeed established by Divine authority, but ordained by human reason; so also there were some ceremonies fixed, not by the authority of any law, but according to the will and devotion of those that worship God. Since, however, even before the Law some of the leading men were gifted with the spirit of prophecy, it is to be believed that a heavenly instinct, like a private law, prompted them to worship God in a certain definite way, which would be both in keeping with the interior worship, and a suitable token of Christ's mysteries, which were foreshadowed also by other things that they did, according to 1 Cor. 10:11: "All . . . things happened to them in figure." Therefore there were some ceremonies before the Law, but they were not legal ceremonies, because they were not as yet established by legislation.

Reply Obj. 1: The patriarchs offered up these oblations, sacrifices and holocausts previously to the Law, out of a certain devotion of their own will, according as it seemed proper to them to offer up in honor of God those things which they had received from Him, and thus to testify that they worshipped God Who is the beginning and end of all.

Reply Obj. 2: They also established certain sacred things, because they thought that the honor due to God demanded that certain places should be set apart from others for the purpose of divine worship.

Reply Obj. 3: The sacrament of circumcision was established by command of God before the Law. Hence it cannot be called a sacrament of the Law as though it were an institution of the Law, but only as an observance included in the Law. Hence Our Lord said (John 7:20) that circumcision was "not of Moses, but of his fathers." Again, among those who worshipped God, the priesthood was in existence before the Law by human appointment, for the Law allotted the priestly dignity to the firstborn.

Reply Obj. 4: The distinction of clean from unclean animals was in vogue before the Law, not with regard to eating them, since it is written (Gen. 9:3): "Everything that moveth and liveth shall be meat for you": but only as to the offering of sacrifices because they used only certain animals for that purpose. If, however, they did make any distinction in regard to eating; it was not that it was considered illegal to eat such animals, since this was not forbidden by any law, but from dislike or custom: thus even now we see that certain foods are looked upon with disgust in some countries, while people partake of them in others.