WE SHALL NEVER KNOW AMBRIOSIASTER'S identity, though we are heir to his commentary on St. Paul's Epistles and 127 Quaestiones on the Old and New Testament. The commentary was once attributed to the great bishop of Milan, Ambrose [Migne put Ambrosiaster's Commentary on Romans in Volume 17, a volume dedicated to St. Ambrose], though St. Augustine refered to it as authored by a "Sanctus Hilarius" or St. Hilary [Contra Duas Epistulas Pelagionorum, 4.4.7]. Erasmus first raised doubt on the authenticity of the Ambrosian authorship of these commentaries, and as a result, Pseudo-Ambrose or Ambrosiaster, a pseudonym for the anonymous writer, was born. Augustine's clue is insufficient to identify the Hilary he mentions. From internal evidence of the works, however, it appears that our Ambrosiaster flourished in the middle-to-late 4th century A.D. It is apparent from reviewing this commentary, that the Pauline teaching of the natural moral law, as developed or taught by the Apostolic fathers, had by then had become fixed and well-defined. Ambrosiaster himself, as one of his commentators has made clear, "co-opted and 'biblicized' the Stoic theme of natural law." (Lunn-Rockliffe, 176)
Naturally, Ambrosiaster addresses the issue of the natural moral law when construing Romans 2:14-15. Ambrosiaster identifies the "law of the heart" as performing the work of the law, but working not through the letter, but by conscience. Ambrosiaster also sees the natural law as contained within the entire Mosaic law. The Mosaic law is "triplex," and one of its three branches is the natural moral law:
In fact, the law has three parts to it. The first part concerns the mystery of God's divinity: the second is what is fitting according to the natural law, which forbids sin, and the third is the deeds of the law, in other words, sabbaths, new moons, circumcision, et cetera. This here is the natural law, which was partly reformed and partly confirmed by Moses, which made sin known to those who were bound in wickedness . . . .III.20.
Triplex quidem lex est, ita ut prima pars de sacramentis divinitatis sit Dei; secunda autem quae congruit legi naturali, quae interdicit peccatum; tertia vero factorum, id est sabbati, noemeniae, circumcisionis et cetera. Haec est ergo lex naturalis, quae per Moysen partim reformata, partime auctoritate ejus firmata in vitiis cohibendis, cognitus fecit peccatum.
"The connection between Mosaic law and natural law was, for Ambrosiaster, smooth; he characterized the ten commandments as 'natural law which--being partly reformed by Moses, partly confirmed by his authority--brought about the recognition of sin through its restriction of vices.'" (Lunn-Rockliffe, 52, citing III.20.4) For Ambrosiaster, the natural law governs the life of man. "It is no secret that the whole life of man is under the law of nature, which has been given to the world. This is the general law." Non est occultum omnem vitam hominis esse sub lege naturae, quae data est mundo, haec lex generalis est. VII.1, 2. This general law did not have to be written, as it was written in the hearts of men. Again, consistent with the main Christian teaching, Ambrosiaster ties in the natural law with the Golden Rule. Quaest., 4.1 (Lunn-Rockliffe, 51)
Originally, law did not have to be given formed in letters, because it was somehow sown in nature itself [quia in natura ipsa inserta quodam modo est] and knowledge of the creator did not lie hidden from the generations of men. For who does not know what is appropriate to the good life, or who is ignorant of the fact that he does not want done to himself, should not be done to another?Quaest., 4.1 (Lunn-Rockliffe, 51)
Taking an approach quite different from Origen, who saw the natural law as unable to witness to the righteousness of God and the mercy of Christ, Ambrosiaster sees in the natural law as guiding the "work of the law," which is faith. Confronted with the Word of God and its revelation, the natural law requires a natural faith, a natural faith that takes us to the very threshhold of supernatural faith in Christ which is a gift. We have, therefore, an obligation under the natural law to believe in God, and, with a natural faith, in his Christ.
The meaning here [Romans 2:14] is that those who believe under the guidance of nature [quia dum natura duce credunt] to the work of the law [opus legis ostendunt], not through the letter but through their conscience [non per litteram, sed per conscientiam]. For the work of the law is faith [Opus autem legis est fides], which although it is revealed in the Word of God, also shows itself to be a law for the natural judgment [naturalis judicio ostendit semetipsum lege sibi esse], since it goes beyond what the law commands and believes in Christ [quia quod mandat lex, ultra facit, ut credat in Christum]. These people believe because of the inner witness of their conscience, because they know in their conscience that what they believe is right--for it is not inappropriate for the creature to believe and worship his Creator [congruum est enim creaturae credere et venerari suum Conditorem], nor is it absurd for the servant to recognize his Lord [nec absurdum est, ut dominum servus agnoscat].II.15. The evidence of nature, the promptings of conscience, and the natural law, like the law of Moses, impel one towards believing in God and in his Son. The law alone is unable to do this, but must act in combination with the order of creation and the witness of conscience. Together, these three combine in an obligation to believe in God. Rejection of the natural obligation to believe in God, an obligation imposed on us from the mere observation of the created world around is, is an event of guilt.
[T]he human race is made guilty by the natural law. For men could learn this [the existence of God as creator of heaven and earth] by the law of nature, with the structure of the world bearing witness that god, its author, is the only one who ought to be loved, something which Moses later put down in writing.I.18. Ambrosiaster teaches that atheism, even agnosticism, would be a sin against the natural moral law. We have all an obligation, under the natural law (and the Jews under the law of Moses in addition to the natural law), to believe in God, even to have natural faith in Christ. Paul therefore "indicts those who lived without law, whether natural or Mosaic [reos facit eos qui sine lege vixerunt et naturae et Moysi]. For by the habit of sinning [consuetudine enim peccandi], they broke the law of nature [obruerunt legem naturae], wiping out any memory of God [oblitique memoriam ejus]." I.19(20) Again elsewhere, Ambrosiaster repeates his doctrine:
Per naturalem ergo legem reum facit genus humanum, potuerunt enim id per legem naturae apprehendere, fabrica mundi tostificante, auctorem Deum solum diligendum, quod Moyses litteris tradidit.
The Gentiles [are uncircumcised and do not keep new moons or the sabbath or the law of foods, yet under the guidance of nature they believe in God and in Christ [et duce natura credunt in Deum et Christum], in other words, in the Father and the Son. This is what it means to keep the law--to acknowledge the God of the law. . . . [hoc est enim legem servare, Deum legis agnoscere].II.14 The obligation to believe in God is the chiefest of all obligations of the natural law, and is greater even than the obligation not to sin in other particulars. Disbelief in God is an offense against the natural moral law most egregious.
Just as the Gentiles, even if they keep the natural law, will perish if they do not accept the faith of Christ--for it is a greater thing to confess belief in one Lord, since God is one, that it is to avoid sinning (for the first of these has to do with God, the second with us)--so also the Jews who live under the law will be accused and judged by the law, since they have not accepted the Christ who was promised to them in the law.II.13 It is not knowledge of the law that justifies, but the doing of the law that justifies. One thinks here of the statement in the Imitation of Christ: "I would rather feel compunction than define it." Opto magis sentire compunctionem quam scire definitionem. Imit. Chris.I.3. Ambrosiaster would rather have someone feel the law and obey it connaturally, as it were, than be able to define it in the manner of the Pharisees, but poorly keep it. "[J]ust as the the person who sins without the law will perish, so also the one who has kept the law without knowing it will be justified. For the keeper of the law maintains his righteousness by nature. If the law is given, not for the righteous but for the unrighteous, whoever does not sin is a friend of the law." II.13. Ultimately, the natural law and our conscience will judge us. And we will have need of the mercy of Christ, for"the law has no authority to forgive sin." III.21. As Ambrosiaster cleverly puts it:
Sicut gentiles ac si legem naturae custodiant, peribunt tamen nisi acceperint fidem Christi; maior enim cause est solum Deum porfiteri, quod Deus unus sit, quam a caeteris abstinere peccatis; haec enim Dei causa est, illa nostra. Ita et Judaei sub lege agentes, a lege accusati judicabuntur: quia non recipiunt Christum in lege promissum.
There are two thoughts inside a man which will accuse each other--the good and the evil. The good accuses the evil because it has denied truth, and the evil accuses the good because it has not done what it knows to be right.II.16. The lack of remedy for sin in the natural law is what required a new dispensation in Christ, a dispensation ushered in through the law of faith by the infinite mercies of God. "Hence the need for Christ to deliver a new law to mankind; in this new dispensation, the apostles and their episcopal successors were given the capacity to forgive sins on God's behalf." (Lunn-Rockliffe, 51, citing Comm. Rom., IV:15). This "new law was a law of the Spirit, 'not written in letters, but intimated to souls through faith, not [a law] which teaches visible things, but one which persuades beliefs in invisible things, which our reasoning deduces spiritually, not things which the eye discerns." (Lunn-Rockliffe, 53, quoting III.17) Reverting to a simpler Abrahamic faith from the onerous Mosaic law, Christ willed "that the human race should be saved by faith alone, along with the natural law [quia consulens Deus infirmitati humanae fide sola, addita lege naturali, hominum genus salvari decrevit]." (Lunn-Rockliffe, 53, quoting Comm. Rom., I:11.2) Therefore, the natural law is not abrogated by Christ in the manner the the judicial and ceremonial rituals of the Mosaic law, but spiritualized, confirmed, and wrapped up in a mantle of Christ's law of faith and grace.
Duae enim cogitationes in homine invicem se accusabunt, bona et mala. Bona accusat malam, quia contradixit veritati: mala iterum accusat bonam, quia non secuta est, ut sensit . . .
It is clear that Ambrosiaster is at odds with Origen on the role of the natural law and faith in God generally, and in Christ specifically. Ambrosiaster gives the natural law a much larger role to play in the area of demanding a natural faith, as it were, a natural faith that leads us to the gates of a supernatural faith. Were he before us today, Ambrosiaster would also clearly reject the etiamsi daremus Deum non esse of Huig de Groot (Hugo Grotius) who, in the Prelegomena of his work De Jure Belli ac Pacis, first intimated a proto-secularizing Enlightenment view of natural law, and announced the possibility of what to Ambrosiaster would be both an oxymoron and an enormity: a natural law without God.
*English translation taken from Gerald Bray, trans. "Commentaries on Romans and 1-2 Corinthians, Ancient Christian Texts (Intervarsity Press, 2009) Cites to "Lunn-Rockliffe" refer to Sophie Lunn-Rockliffe, Ambrosiaster's Political Theology (Cambridge: Cambridge University Press, 2007).