After the Original Sin, man was left in a condition of alienation from God. Whereas before the sin, he enjoyed infused knowledge in his intellect, loving obedience in his will, spontaneous virtue in his emotions, and no sickness or death in the body; after the fall, he is punished with ignorance in the intellect, malice in the will, concupiscence in the emotions, and suffering and death in the body. God himself has to grant the remedies. These are principally two: The Divine Law and grace.
Law, according to St. Thomas is “nothing else than an ordinance of reason for the common good, made by him who has care of the community, and promulgated.” To the modern mind, the idea that “law” has anything to do with Heaven is a bit odd, but in article two of that same question, St. Thomas explains that law is intended to guide us toward our last end. This end is Heaven. The Natural Law, which is the participation of the rational creature in the Eternal Law, is not sufficient for this end, since the end is supernatural. Human laws – even ecclesiastical laws – are also insufficient for this, since they do not come from God and therefore cannot lead to God. Only God himself can give us a law that will lead us to this end. This law is called the Divine Positive Law.
It has two phases, the Old Law and the New Law, corresponding to two priesthoods: the priesthood of Aaron and the priesthood of Christ. The Old Law was both holy and inadequate. It served to prepare a people for the New Law and grace.
I will treat the subject of the Old Law under three headings: (1) essence and advantages, (2) inadequacy, and (3) specifically preparatory aspects.
Essence and Advantages. The Old Law was an important part of God’s preparation of man to receive the promise contained in the Protoevangelium, the first good news announced to our parents immediately after the fall. This promise was of the Messias and the grace that he would mediate.
The Old Law was given through the ministry of angels to Moses on Mount Sinai. It established a consecrated “People of God”, no mere earthly nation, but a divine commonwealth which was also the people out of whom the promised Messias would come.
The Law confirmed and restated the Natural Law, making it clearer and more explicit. This confirmation of the Natural Law comes principally through the Decalogue, about which St. Augustine says: “God wrote on the tables of the Law what men did not read in their heart.” Beyond this, the commandments of the Decalogue “lay the foundations for the vocation of man fashioned in the image of God; they prohibit what is contrary to the love of God and neighbor and prescribe what is essential to it.” Because it lays this foundation, the Old Law has as its end union with God in Heaven by living the life of grace here. This, the Natural Law did not have.
In the Decalogue, we distinguish three different sets of prescriptions: the moral, the ceremonial, and the juridical. The moral precepts are the ten commandments considered generally. In them is the Natural Law restated and made clearer. The ceremonial prescriptions of the first tablet, containing the first three commandments, regulate the cult of divine worship. These commandments have God as their immediate object and therefore correspond to the first of the two great Evangelical Commandments. The juridical precepts, contained in commandments four to ten – the second tablet, corresponding to the second Evangelical Commandment – are a rule by which man’s behavior with his fellows is measured. The rest of the Torah contains minute prescriptions of the ceremonial and juridical law. These tutored the People of God in Christ, preparing them to receive him when he came. This is so much the case that those of this nation who rejected him were more blameworthy than the pagans, as Our Lord told Pilate.
With the revelation of the Old Law, God gave the remedy for one of the effects of the fall: ignorance.
Those who properly observed the Law with divine faith, received grace and were made interiorly right with God; that is, they were justified. (Faith in the true God and in the Redeemer to come were necessary parts of this.) For all of its inadequacy without faith, the law could and did provide the means of sanctification for the faithful, anticipating, as it were, the grace of the New Law. “The external practices are ordered to an interior formation. Charity as the love of the Holy Spirit and faith as embraced in the Holy Spirit are the first principles of the Old Law. The founder of the community demanded that the exterior rituals reflect these interior states of mind.”
Inadequacy. The Old and New Law are compared as the imperfect to the perfect. While both are ordered to Heaven (Veritas), the New Law has the imago of the Heavenly reality (Christ) whereas the Old had merely the umbra, or shadow, of it.
The Old Law was generally divided by the Rabbis into 613 mitzvot, “laws,” minute precepts of which 248 were commands and 365 were proscriptions. The point of all this minutiae was to instruct Israel as one would instruct a child, by constant repetition and minute strictures. For all that, the Israelites still rebelled against the first and most basic precept, monotheism. In keeping with this imperfect nature, while the end of the Old Law is Heaven, it made many promises of an earthly nature in order to attract a carnal-minded people to the practice of virtue (as one promises a lollypop to a child as a reward for the decent behavior an adult would spontaneously perform). Thus, temporal prosperity and long life are given as rewards for fidelity to the law. The examples of Job, Tobias, and Judith come to mind. All were rewarded for their virtue in this manner.
By contrast, the New Law is for adults. The prescriptions are relatively few and intended for those who are mature.
As a remedy for the effects of the fall, the Old Law was incomplete. It cured ignorance in the intellect by imparting the divine revelations that came to Moses on Mount Sinai, but it did not give the cure for malice in the will. “For the law brought nothing to perfection.” It was essentially preparatory and dispositive in that it removed the obstacles to the cure (the sins which would keep man from receiving the Holy Ghost through the Messias), but it did not offer the complete cure. This “complete cure” is grace, which the New Law gives in and of itself through the interior infusion of the Holy Ghost and sacraments that work ex opere operato (those of the Old Law worked ex opere operantis).
Because the Law could not impart grace of itself, St. Paul could tell the faithful of Rome that they were “not under the [Mosaic] law, but under grace.” St. John could similarly write: “For the law was given by Moses; grace and truth came by Jesus Christ.”
Another mark of the inadequacy and imperfection of the Law is that it “killed.” St. Paul called it “the ministration of death,” a turn of phrase theologians explain in these terms: The Mosaic Law, good and holy in itself, did not cause death efficialiter, but occasionaliter. By giving the commands (and thus removing ignorance and its consequent excuses), while not bestowing the grace to follow them, it became an occasion of sin. With great pathos, the Apostle explains this dilemma: “sin taking occasion by the commandment, wrought in me all manner of concupiscence. … And the commandment that was ordained to life, the same was found to be unto death to me.”
Specifically Preparatory Aspects. The primary precept of the Law was monotheism. The most important subject of the Old Testament prophesies was the coming of the Messsias (the “Day of the Lord”), who had been promised in the Protoevangelium. Together, these aspects of their law taught the faithful of Israel that the Author of nature and the supernatural order – their God – was also the Father of the Messias to come.
The ceremonial and juridical precepts of the Law are fulfilled in Christ’s New Law.
The ceremonial precepts, which mandated numerous sacrifices of propitiation and reparation, graphically imbuing the notion of redemptive suffering, were fulfilled in Christ’s Passion. “The sacraments of the Old Law did not confer grace, but they did look forward to the future Messiah.” All of the bloody sacrifices of the Mosaic Law were types of the Victim prophesied so explicitly in Isaias 53 and Psalm 21. In St. Paul’s Epistle to the Hebrews, he dwells at length on various details of Mosaic worship, showing that Christ’s sacrifice was the fulfillment of the Temple cult. It is with this preparatory function in mind that he tells the Galatians “the law was our pedagogue in Christ, that we might be justified by faith.” Thus, the figurative sense of these ceremonies was more important than the literal.
The juridical precepts, found mostly in the book of Deuteronomy, were a preparation for the law of Christ as a law of Charity in the Holy Ghost. With great emphasis on justice, the Law also laid emphasis on mercy in such prescriptions as “the jubilee year of forgiveness of debts, prohibition of loans at interest and the keeping of collateral, the obligation to tithe, the daily payment of the day-laborer, the right to glean vines and fields [which we see so beautifully observed and augmented by Booz in the book of Ruth] (2:15-16).” “The Juridical precepts of the Old Law are brought to completion because Jesus shows us what our relationship with our neighbor is to be like.” Our Lord showed us this chiefly by the example of his holy life, but he also preached it, especially in the Sermon on the Mount, the Mount of Beatitudes being the antitype of Mount Sinai, as many commentators hold.
Numerous other New Testament antitypes were prophesied or foreshadowed in the law: Our Lady, the Church, the Apostles, the Sacraments (especially the Eucharist), the Mass, etc.; but all these are ordered to Christ and to Man’s orderly return through him, and in the Charity of the Holy Ghost, to intimate communion with the Blessed Trinity.
Truly, we can say with St. Paul, “For the end of the law is Christ,” and add to it the words of St. Ambrose: “end not in the sense of a deficiency, but in the sense of the fullness of the Law: a fullness which is achieved in Christ…. Therefore, the Mosaic Law is an image of the truth.”
 Summa Theologiae, Ia, IIae, Q. 90, A. 4.
 Acts 7:53, Gal. 3:19.
 Summa Theologiae, Ia IIae, Q. 100, A. 5, ad corp.
 Quoted in Catechism of the Catholic Church, n. 1962.
 John 19:11.
 Class notes, loc cit.
 Heb. 7:19.
 Rom. 6:14.
 John 1:17.
 2 Cor. 3:7.
 This is the concept, in moral theology, of invincible ignorance: “For until the law sin was in the world; but sin was not imputed, when the law was not” (Rom. 5:13).
 Rom. 7:8,10.
 Gal. 3:24.
 Rom. 10:4.
 Quoted in Pope John Paul II, Veritatis Splendor, No. 15.