Retroactive laws present vexing problems for lawyers. On one hand, they are awfully convenient, especially when a problem with the law is discovered. On the other hand, they are a favorite tool of tyrannies like Nazi Germany. They are especially disfavored in the penal context, especially in the Anglo-American tradition of the seventeenth and eighteenth centuries. However, the problem remains present in the jurisprudence of the twentieth century, notably in the work of Lon Fuller. Yet the condemnation of retroactive laws has deep roots in the classical legal tradition, going back to Justinian and Gregory IX’s Liber Extra. Indeed, one can find condemnations of the concept all the way back to Ancient Rome. Given that retroactive laws—and putatively retroactive administrative regulations—remain troublesome for lawyers and judges, the tradition provides an under-utilized source for considering the problem.
More than that, there is a pervasive sense that liberal jurisprudence is fundamentally liberal not only in its effects but also in its origin. That is to say, liberals developed the jurisprudential principles that secure liberalism. The prohibition against retroactive laws seems like an especially clear example. Indeed, the connection often drawn between Nazi Germany and retroactive laws gives away the game: tyrannical, totalitarian states like retroactive laws because they terrorize their subjects. Liberal democracies, however, have no need of such laws (except, of course, when they do). The classical tradition’s condemnation of such laws, outside narrow exceptions, undercuts this self-image of liberalism. No one would accuse Justinian of being altogether liberal, yet throughout his Corpus Iuris one finds condemnations of retroactivity. Likewise, Gregory IX, who adopted Justinian’s enactment verbatim, is not generally considered even a proto-liberal.
One finds readily in the Anglo-American tradition harsh condemnation of retroactive penal laws. Perhaps the harshest is in the twenty-eighth chapter of Hobbes’s Leviathan, where Hobbes outlines the various defects in an act of punishment. Among the defects, Hobbes states that punishment according to a retroactive law is not punishment at all, but “an act of hostility.” Without a law at the time of an act, there is no transgression of the law. In the second section of the introduction to his Commentaries, Blackstone sees an inherent connection between the requirement that a law be promulgated and a ban on ex post facto laws. One defect in promulgation, for Blackstone, is promulgating a law in an unreasonable manner—he cites the example of Caligula, promulgating laws in small text high on a pillar. He calls ex post facto laws “still more unreasonable,” since they punish conduct only after it happens. For Blackstone, laws must be in futuro and noticed before they take effect.
It would, however, be a mistake to think Blackstone’s connection between promulgation and retroactivity was novel. St. Thomas Aquinas includes promulgation as an essential element of law, along with his usual definition (an ordinance of reason ordered to the common good by one having public authority) (ST I-II q.90 a.4 co.). Indeed, for Aquinas, promulgation is necessary for the law to have force (ibid.). Aquinas anticipates Blackstone’s connection in an interesting way. One objection Aquinas sees is that, while laws have future effect, promulgation concerns only those who are present (ST I-II q.90 a.4 obj. 3). He answers this with recourse to Isidore’s definition of law: the promulgation extends to the future because the written law serves as a perpetual promulgation—after all, for Isidore, the very name of law (lex) comes from the fact that it is written (legere) (ST I-II q.90 a.4 ad 3).
It is worth noting briefly that Aquinas’s notion that promulgation is a necessary component of law comes out of the tradition. Gratian argues that “ordinances are instituted when they are promulgated” (D.4 d.p.c. 3). He goes on to add another condition: “they are confirmed when they have been approved by the usage of those who observe them” (ibid.). Aquinas does not explicitly add this second condition, though he certainly discusses custom as a source and interpreter of law (ST I-II q.97 a.3). This is not the place to compare Gratian’s treatment of custom in D.4 with Aquinas’s. Instead we will note that Aquinas follows Gratian in concluding that promulgation is necessary for law.
At any rate, one may or may not find Isidore’s definition especially compelling. However, Aquinas’s objection and argument are at the very center of the tradition. The objection hinges on the Codex of Justinian, which collects a rescript of Valentinian and Theodosius to Cyrus, the praetorian prefect and consul designate (Cod. 1.14.7). That provides that “laws and constitutions create a rule for future cases and cannot be applied retroactively to past acts, unless provision has expressly been made concerning the past for cases that are still pending” (ibid.). There are other examples of this principle in Justinian’s Corpus Iuris. For example, in the Digest one reads, “[a] penalty is not imposed, except that which is laid down specially for the delict in question by each law or some other provision” (Dig. 50.16.131).
This classical tradition found its way into the canon law of the Church, too. In the Liber Extra, we find that Gregory IX, writing to the archpriest of the Basilica of St. Mary Major, quoted the aforementioned rule of the Codex verbatim (X 1.2.13). Gregory wrote his letter sometime between March 21, 1227 and September 4, 1234. But its inclusion in the Liber Extra guaranteed that it would have a significant effect on the common law of the Church until the twentieth century. From this we may say that the prohibition on retroactive laws with a limited exception was part of the ius commune; certainly, it was attested both in the civil and canon law. The peculiar horror of the English toward such laws—as evidenced by Hobbes and Blackstone to take two examples at random—may well have been sharpened by the history of England. But it was not unique to the English. The classical legal tradition was opposed to retroactivity well before Henry Tudor noticed Anne Boleyn.
Nevertheless, the English horror of ex post facto laws made its way to the United States. Article I, § 9, cl. 3 of the United States Constitution forbids Congress from making ex post facto laws, linking them with another grisly relic from England in the sixteenth and seventeenth centuries: the bill of attainder. Not content to keep the United States out of the ex post facto law business, the framers, in Article I, § 10, forbade the states from making ex post facto laws. The United States Supreme Court, in Calder v. Bull, however, emphasized that the prohibition applies for the most part to penal laws. In his opinion in Calder, Justice Samuel Chase distinguished between ex post facto laws, which are forbidden, and merely retroactive laws, which, while they may not be prudent, are not forbidden. But this has not really reduced the difficulty with retroactivity in the law.
And the difficulty extends clearly into the realm of morality. For example, Lon Fuller, in The Morality of Law, worked through several examples to underscore the problem of retroactivity. On one hand, retroactivity seems like an elegant solution to pressing problems—an “indispensable . . . curative measure.” On the other hand, it leaves individuals dangerously uncertain about their rights and obligations. However, early on in his analysis he points to an example that perhaps gives away the game: the Reichstag passed a retroactive law in 1934 after the so-called Night of the Long Knives, sanctioning the murders of Ernst Röhm and some hundreds of others at the behest of Adolf Hitler. In their Morality of Administrative Law, Cass Sunstein and Adrian Vermeule observed that the Third Reich and its legal system had a “formative impact” on Fuller’s jurisprudence. In fact, Sunstein and Vermeule find citations in Fuller’s work that support the conclusion that he was far from sure that there was any sort of legality or legal system in the Third Reich. Therefore, Fuller’s quick reference to the Night of the Long Knives must be taken, ultimately, as a major objection to retroactive laws, whatever else he does later in his treatment to demonstrate their complexity—including their convenience.
Nor was Fuller the first person to connect the Third Reich with retroactive laws. For example, Jerome Hall, writing in the Yale Law Journal in 1937 on the closely related principle nulla poena sine lege, cites not only the “lex van der Lubbe” but also the law retroactively approving Hitler’s conduct during the Night of the Long Knives as “[r]ecent examples of ex post facto legislation.” Hall, looking to the pronouncements of Hans Frank, implies that retroactive legislation is a favored weapon of regimes seeking especially to terrorize criminals into obedience. In other words, even before the whole horror of the Reich was revealed to the world, there was a sense that the retroactive law was a special tool of the Nazi regime.
As noted earlier, Aquinas sees promulgation as an essential part of law (ST I-II q.90 a.4 co.), and it may fairly be said that a law that is not promulgated is not a law as far as Aquinas is concerned. More than this, one may assume that Aquinas would hold that a law with a defect in promulgation was unjust, which is to say no law at all (ST I-II q.96 a.4 co.). Indeed, one could argue that the enforcement of such a law is an act of violence (ibid.). Finally, Aquinas was aware of the Codex and its rule that law applies only to future cases, citing it specifically in the context of promulgation (cf. ST I-II q.90 a.4 obj. 3).
One may argue, in any event, that Aquinas acknowledges the classical and canonical rule against retroactivity and connects it fundamentally with the essential requirement of promulgation. Here, he anticipates Hobbes and Blackstone. Enforcing a law against conduct that happened before the law was promulgated is, for Thomas Aquinas, an act of violence; the Common Doctor would likely agree with Hobbes that such enforcement is an “act of hostility.” Likewise Aquinas anticipates Fuller and Hall: the enforcement of such laws is immoral insofar as it is unjust. Indeed, Aquinas would go beyond Fuller and Hall in all likelihood and argue that, whether it is the wicked Nazi regime or some generally benevolent regime, the enforcement of such laws is unjust and violent.
Well, maybe. Given that Gregory IX ratified the provision of the Codex permitting express retroactivity for pending cases, one may also assume that Aquinas would recognize that the rule against retroactivity is not absolute. But the precise contours of the rule and Aquinas’s reception of the rule are perhaps not as important as what the example demonstrates. And what the example demonstrates is this. One can construct a compelling case against retroactive legislation from Justinian’s Codex and Digest, from Gratian’s Decretals, and from Thomas Aquinas’s theory of law. In many respects, this case anticipates the arguments of Hobbes and Blackstone, of Fuller and Hall. One need not even consider the more modern, more obviously liberal sources at all. Once again, one discovers that fundamentally modern—indeed, fundamentally liberal—concepts are rooted in the classical legal tradition.
Pat Smith
