The Collatio legum Mosaicarum et Romanarum (Comparison of Mosaic and Roman Laws), otherwise known as the Lex Dei (Law of God), is a fascinating source which witnesses a fourth-century attempt at creating comparative law. As such, it is a vital source for our purposes, demonstrating the desire of a likely Christian compiler (although see the discussion below) to marry Roman law with biblical law, not only minimising any tension that was understood to exist between the two, but also to make the suggestion that the latter directly influenced the former. The work is preserved in three manuscripts: Codex Berolinensis Lat. Fol. 269 from the ninth century, Codex Vercellensis n. 122 from the tenth or eleventh century, and Codex Vindobonensis n. 2160, from the ninth to eleventh century (Frakes argues for the ninth, although traditionally this codex has been dated to the tenth or eleventh century; Compiling the Collatio, p. 37). The text was discovered in the sixteenth century, published initially in 1574. The 1913 edition of Moses Hyamson includes a facsimile of the Berlin manuscript, which is viewable here: https://archive.org/details/cu31924029129876 (on the manuscript tradition, see Fritz Schulz, “Manuscripts of the Collatio,” and more recently the summary by Frakes, Compiling the Collatio, p. 35-51). In total, the Collatio consists of sixteen chapters, or titles, which each offer a legal prescription from four of the books of the Pentateuch (Exodus, Leviticus, Deuteronomy, or Numbers), immediately followed by parallels from Roman law intended to highlight their compatibility. The biblical text is usually introduced with the formula Moyses dicit (“Moses says”) or Moyses Dei sacerdos haec dicit (“Moses, the priest of God, says the following”). The scriptural quotation is then followed by extracts from Roman jurists and the imperial constitutions. The biblical text used appears to be closer to the Old Latin than the Vulgate (the former refers to the Latin translations of the Bible which were made before Jerome’s Vulgate in the late-fourth century; that the collator used the Old Latin Bible is suggested in part by the fact that Jerome had not yet finished translating the books used in the Collatio at the time when it was most likely written; see Frakes, Compiling the Collatio, p. 88). There is a rough structure which mirrors the latter half of the Decalogue, or the Ten Commandments, with the topics covered as follows: homicide, assault, mistreatment of slaves, adultery, homosexuality, incest, theft, false witness, witness of family members, deposit, cattle rustling, arson, moving of boundary markers, kidnapping, sorcery and astrology, and intestate succession (Simon Corcoran, Collatio legum Mosaicarum et Romanarum, p. 1648). The illustrative extracts above come from the sections treating kidnapping and sorcery and astrology.

The first external reference to the Collatio is found in the writing of bishop Hincmar of Reims in 860 CE, who alludes to the chapter treating homosexuality. Frakes argues that internal evidence helps to date the terminus post quem to shortly after 390 CE.  The compiler seems to have had access to the writings of Papinian, Paulus, Gaius, Ulpian, and Modestinus, five jurists from the classical period who were later also appealed to in the Law of Citations of Theodosius II and Valentinian III issued in 426 CE, and surviving in the Theodosian Code 1.4.3. Some older scholars argued that this means the compiler of the Collatio was writing after 426, however, the works of these jurists was popular, and was used and copied in the fourth century. Moreover, Frakes notes that some of the works quoted from these authors is actually inauthentic material from the third and early-fourth centuries (Frakes outlines further internal evidence for his more precise dating of the text to between 392-395 CE, which cannot be detailed here in the interests of space, but see Compiling the Collatio, p. 35, 51-65). In addition to the writings of the five jurists above, and pseudonymous writings attributed to them, the compiler evidently had access to a library of Roman legal sources which included the Codex Gregorianus (a collection of constitutions from Roman emperors from the second to late-third centuries CE, which was possibly collated at the end of the third century), and the Codex Hermogenianus (a collection of constitutions from the emperors of the first tetrarchy: Diocletian, Maximian, Constantius, and Galerius, largely from 293-294 CE).

Fritz Schulz argued that the Collatio was actually the work of a series of compilers through the fourth century (Schulz, History of Roman Legal Science, p. 310-311). However, as Frakes recognises, the evidence, both external and internal, lends no firm support to this theory, and the structure and form of the text is fairly uniform throughout. A single compiler is therefore more likely (Frakes, Compiling the Collatio, p. 65). The precise identity of this author is not known, but scholars have either identified this individual as a Jew, or a as a Christian whose aim was to show pagan lawyers that the Christians could appeal to a long-established legal tradition which was not only older than that of the Romans, but compatible with it. Over the years various suggestions have been made, with figures such as Ambrose of Milan, Rufinus of Aquileia, and Jerome being put forward as the author of the Collatio (for the bibliography, see Frakes, Compiling the Collatio, p. 125 n. 6). However, the tendency now is to recognise that there is no clear evidence for any such individuals having composed the text. The sources used indicate a lawyer with a good Roman legal education. It would seem unlikely that the author was a pagan, as he seemed to be familiar with the Bible, and viewed it as divinely inspired. In 1930, Edoardo Volterra put forward the theory that the author was a Jewish Talmudic scholar aiming to explain Judaism to the Roman elite (see Volterra, Collatio; see also Leonard V. Rutgers and Scott Bradbury, “The Diaspora, c. 235-638,” p. 504-505). However, this suggestion, while taken up by others since, can be challenged on several grounds. For instance, the emendations of the biblical texts used make them less akin to the Hebrew text and the Greek of the LXX, and more akin to the Old Latin Bible (see Frakes, Compiling the Collatio, p. 131; for a summary of the other arguments related to Jewish authorship, see p. 130-135). In favour of a Christian author, Frakes has drawn attention to Christian interest in the laws of the Hebrew Bible in texts such as the Didache and the Didascalia Apostolorum, as well as Tertullian’s assertion in his Apology XLV.4 that Roman laws are derived from those of Moses. Frakes’s suggestion is that the author was a Christian jurist in Italy who wished to get pagan colleagues on side. He even suggests that the author’s efforts could be in response to the recent usurpation of Eugenius, and the moves by certain figures at this time to restore various aspects of paganism (see the commentary on Ambrose, Letter XLI; Frakes, Compiling the Collatio, p. 149). However, such a precise historical context is problematic in that the Collatio could have been motivated by numerous factors, and not necessarily in response to such a specific event.

The question of authorship remains uncertain, but what seems clear is that the compiler seemingly had a specific method when composing the Collatio. Contrary to some who have suggested that he worked randomly (e.g. Jill Harries, “How to Make a Law Code,” p. 68), Frakes points to passages such as V.3.1, which claims that the author in fact wanted to make connections between biblical and Roman law in a logical and methodical way. He follows the second half of the Ten Commandments (Exodus 20:2-17; Deuteronomy 5:6-21), and at times trims down or edits the biblical text to omit material which did not have parallels in Roman law. For example, in the section on assassins and murderers, he quotes from Numbers 35:16-17, 20-21, leaving out verses 18-19, which refer to a person who kills another with a wooden weapon, and the “avenger of blood” who puts the murderer to death (NRSV). These verses are in the LXX and the Old Latin Bible which the compiler likely used, and so he probably left them out because Roman law had nothing specific to say about wooden weapons, and the “avenger of blood” is similarly something from Hebrew law which did not find a Roman counterpart (see Frakes, Compiling the Collatio, p. 116).

We now turn to a brief discussion of the extracts quoted above, which simply serve as illustrative examples of the format of the Collatio, demonstrating the format that the text takes and showing the manner in which the compiler utilised both biblical texts and Roman law to achieve his aim of highlighting their compatibility. The first extract from title XIV deals with kidnapping, entitled De Plagiariis (Frakes in his commentary on this passage points to various secondary sources treating kidnapping in Roman law, including Olivia Robinson, Criminal Law, p. 32-35, and Richard Bauman, Crime and Punishment, p. 110-112. For others, see his Compiling the Collatio, p. 297 n. 17). Scholars have disputed the source of the biblical text quoted at the beginning of title XIV, with Moses Hyamson citing Exodus 21:16, but also noting the apparent similarity with Deuteronomy 24:7 (Mosaicarum et romanarum legum collatio, p. 277). Parts of both texts seem to have been used in the compiler’s citation, with Deuteronomy having the specific reference to the kidnapping of an Israelite, as opposed to the more generalised text of Exodus. Schulz suggests that when describing the act of kidnapping, the compiler replaced the verb involo, which appears in the text Old Latin Bible, with plagio because the latter was the Roman term for kidnapping (“biblischen Texte,” p. 39). This instance of editing on the behalf of the compiler therefore shows the way in which he wished to bring biblical and Roman law closer together. The text quoted as Paulus is actually Pseudo-Paulus’s Sententiae (Sentences) V (at V.30b in the edition of Paul Krüger, p. 135). It has been suggested that a constitution of Constantine dated to 315 CE (Theodosian Code 9.18.1) was of influence to the compiler here (for the references, see Frakes, Compiling the Collatio, p. 298). For Ulpian’s text, see the edition of Otto Lenel, col. 985. The late-republican Lex Fabia outlined punishments for kidnapping and for aiding and abetting kidnapping (see Michael Crawford, Roman Statutes II, p. 755 on this issue). One interesting feature of the Collatio is the distinction that is frequently made between honestiores (used of respected, more honoured citizens) and humiliores (used of more common citizens), which became more prominent in Roman law after the Antonine Constitution of 212 CE. This granted Roman citizenship to all free people in the empire (see the commentary on P.Giss. 40 and the Constitutio Antoniniana). An example of this distinction appears in the first extract above, at XIV.2.2. The Lex Fabia dictates that humiliores are punished more harshly than honestiores, by being crucified or sent to work in the mines.

The second extract, from title XV, entitled De Mathematicis, Maleficis et Manichaeis, deals with astrologers, sorcerers, and Manichees. Manichees specifically are mentioned just after the text quoted above in XV.3, as being legislated against by the Codex Gregorianus in the seventh book entitled De Maleficis et Manichaeis. In the interests of brevity, I have not quoted the entire texts of the chapters used here as examples (on the subjects of astrology, sorcery, and Manichaeism in Roman law, Frakes points among others to Tamsyn Barton, Ancient Astrology; Peter Brown, “Diffusion of Manichaeism,” p. 92-103; for further references, see Compiling the Collatio, p. 299 n. 18). The biblical text cited by the compiler here is Deuteronomy 18:10-14, although again there are some discrepancies between the text quoted and that of the Old Latin Bible. In fact, the text is closest to Pseudo-Augustine’s Codex Speculum LV, a fifth-century Latin manuscript of the New Testament (see Frakes, Compiling the Collatio, p. 300). Schulz argues that the clause added at XV.1.2 regarding the determining of a baby’s gender in the womb in relation to divination is a gloss which appeared in the manuscript during the Middles Ages (“biblischen Texte,” p. 39-40). This is possible, although augury appears already at the start of the biblical passage cited, and so perhaps a scribe wished to elaborate on types of sorcery. A similar argument could be made for XV.1.2, which lists various types of sorcery (the reference to the snake charmer and necromancy do also appear in the Vulgate). The mention of necromancy might have been influenced by the story in 1 Samuel 28:7-25 of the witch of Endor (Frakes, Compiling the Collatio, p. 300). The reference to the Chaldeans is also interesting, as this is also an addition to the biblical text, which is present in Ulpian’s text quoted afterwards as well. Frakes suggests that in the compiler’s day, Christian emperors had put laws in place banning divination, and these variants in the present text may well simply reflect this, and be an attempt to compare anti-magical material in Ulpian and Deuteronomy, exaggerating the similarities. The text of Ulpian mentions a senatus consultum from the consulship of Pomponius and Rufus, which was during the reign of Tiberius, in the latter part of 16 CE. This law banned the use of astrology for political purposes, and expelled magicians and astrologers from Italy (see also Tacitus, Annals II.32; it has been argued by Zsuzanna Várhelyi that this law was linked to charges of improper divination lodged against a senator named M. Scribonius Libo Drusus: see The Religion of Senators, p. 159).

These examples are merely illustrative, but they give some idea of the way in which the author of the text worked. Ultimately, this source makes a strong statement about the relationship between God and Rome, and divine law and Roman law, feeding into the view that is expressed already in some of the earliest Christian literature that Roman rule is supported by God, with Roman authorities (often unwittingly) carrying out his will even if at times acting in ways seemingly contrary to this. Perhaps in an attempt to minimise tension with legal colleagues and/or other literate Romans, the compiler of this source wishes to make clear, and offer proof by way of authoritative examples from both sides, that God’s laws as recorded by Moses and Roman legislation effectively work towards the same goal.

Other early Christian writers also considered this relationship between Mosaic and Roman law. For instance, the third century CE Didascalia Apostolorum VI.19.5 states: “In the law he (i.e. God) says, ‘You shall not kill.’ If indeed someone kills, he is condemned by the law by the Romans and is under the law.” The author of the Didascalia writes concerning the sixth commandment related by Moses (see Exodus 20:13) that if a person is to commit murder, in addition to contravening the law of the Old Testament, they are also condemned under Roman law. Robert Frakes argues, therefore, that we seem to have here an early attempt to align Mosaic/divine law and the law of the Romans (see Frakes, Compiling the Collatio, p. 138). However, for the author of the Didascalia, there is a clear polemical agenda running through the text, which seeks to make unmistakably clear the differences between Christianity on the one hand, and Judaism and paganism on the other. The context seems quite clearly to be a community of Jewish converts, containing some who are in the author’s view overly concerned with upholding certain Jewish practices (such a purity rituals, food restrictions etc.) The author wishes to temper this and make clear that such adherence is counter to true Christianity. The statement that both the Mosaic law and Roman law condemn murder ought not be over interpreted as complimenting Roman law by highlighting its affinity with that of God. Rather, we must take into account the broader context which seeks to make plain that in Roman society, many strict Jewish rules that were developed after the Decalogue cannot be upheld. It is Roman law that has legal force in society, and this takes precedence in the case of any contradiction between biblical and Roman law.

In the fourth century author Ambrosiaster’s Commentary on Romans 7.1, it is argued that because the Romans are a civilised people, they already practice to a certain degree the ethical precepts of the Decalogue (“natural law” as Ambrosiaster sees it). These precepts are even inscribed in their most ancient legal institution, the Twelve Tables (Jacobs, “Papinian Commands One Thing,” p. 96):

“Therefore, the Romans know what law is because they are not barbarians, but understand natural justice, in part from themselves, and in part from the Greeks, just as the Greeks do from the Hebrews. Before Moses while the law was not hidden, neither organization nor authority existed. For the organization of law was brought to the Romans from Athens (the translation is my own).”

Andrew Jacobs characterises Ambrosiaster as an author who attempts to simultaneously maintain distance from and appropriate Jewish law (“Papinian Commands One Thing,” p. 95). Moreover, he argues that in Ambrosiaster’s conflation of “law” (Christian, Roman, and Jewish), we see a “triangulation of Christian identity actually comparable to that of the collatio.” Ultimately, Ambrosiaster aligns divine law and Roman law (partly through aligning the two tablets of Moses and the Twelve Tables of the Romans), and in this sense seizes the Jews’ sole claim to the Mosaic law. Through his overlapping “condemnation and reconciliation” between Mosaic law and Roman law, whereby the flaws in the Mosaic law are recognised but it is still praised as a positive influence upon Roman legislation, we can perhaps understand Ambrosiaster’s context as one similar to that imagined by the author of the Collatio when he states in VI.7.1 that divine and human (Roman) judgement can “condemn (wrongdoing) with the same voice” (“Papinian Commands One Thing,” p. 97). However, for Jacobs, this attitude does not amount to simple accommodation. Rather, by making clear that God’s law (i.e. the proper fulfilment of “natural law” that Christ brings) transcends both Jewish and Roman law (which are themselves in a hierarchy, as Roman law derives indirectly from Jewish law), Ambrosiaster carves out for himself a religious identity of superiority. In this sense he can be seen to be doing something slightly different from the author of the Collatio, whose purpose seems to be to minimise the perceived difference between the Mosaic and Roman law.