Introduction to Roman private law and the delicts

This note introduces the Roman law of delicts, one of the two principal divisions of Roman private law concerned with obligations arising ex delicto—from wrongful acts—as opposed to those arising ex contractu. The study of delicts forms a cornerstone of the Oxford Mods curriculum in Roman law, providing both substantive doctrinal knowledge and training in the interpretative techniques required to work with primary sources in translation: the Institutes of Justinian (AD 533) and the Digest (or Pandects), compiled under the same emperor's direction.

Roman delict corresponds loosely to the modern common-law tort, though important conceptual differences persist. Unlike modern tort law, which is dominated by a generalised duty of care and the principle of negligence, Roman delict comprised a finite, closed list of named wrongs. The four principal delicts examined in this module are furtum (theft), iniuria (outrage or affront to dignity), damnum iniuria datum (damage wrongfully caused, chiefly governed by the lex Aquilia), and rapina (robbery with violence, treated as an aggravated form of furtum).

Each delict had its own elements, defences, and remedies. The remedies were typically penal in character: a multiple of the loss (poena) rather than simple restitution or compensation. The victim instituted a actio (action) for a fixed penalty or for an amount assessed by the judge (iudex). These actions were in personam—against the wrongdoer personally—and the sums recovered often exceeded the plaintiff's actual loss, reflecting the retributive and deterrent functions of the Roman system.

Understanding delict requires facility with the Roman institutional scheme. Gaius, the second-century jurist whose Institutes influenced Justinian's codification, divided all private law into persons, things, and actions. Delict belongs to the law of obligations, itself a subdivision of the law of things (res). This tripartite structure will recur throughout your studies and is essential context for situating the sources you encounter.

Your principal objective in Week 1 is to acquire a working knowledge of the architecture of Roman private law, the nature and purpose of delictual liability, and the interpretative conventions governing the use of the Institutes and Digest. Mastery of technical Latin vocabulary, though not fluency in the language, is assumed and will grow over the term.

Roman law evolved over more than a millennium, from the Twelve Tables (traditionally dated 451–450 BC) through the classical period (approximately the first to third centuries AD) to Justinian's codification in the sixth century. The law of delicts reflects layers of historical development, from archaic self-help and fixed tariffs to the sophisticated casuistry of the classical jurists.

The Twelve Tables, Rome's first written legal code, provided the foundation. They set out fixed penalties for specific wrongs: for example, talion (retaliation in kind) for membrum ruptum (a limb broken), and a fine of 25 asses for os fractum (a bone broken) inflicted on a free person. Over time, inflation and evolving social norms rendered these fixed sums derisory, prompting the development of more flexible remedies. The praetor—the magistrate responsible for administering justice—played a crucial role, supplementing and reforming the ius civile (civil law) through his annual edict. By promising new actiones (actions) or adapting existing ones, the praetor introduced remedies for wrongs not covered by the Twelve Tables, such as dolus (fraud) and metus (duress).

The classical period witnessed the maturation of Roman jurisprudence. Jurists such as Ulpian, Paul, Gaius, and Papinian wrote extensively on delict, producing responsa (opinions), quaestiones (problem-discussions), and commentaries on the praetor's edict. Their writings survive principally in fragments excerpted in Justinian's Digest, a massive compilation organised into fifty books and subdivided into titles and fragments. The Digest aimed to preserve the ius (law) as elaborated by the classical jurists, though Justinian's commissioners edited and sometimes interpolated the texts to reflect sixth-century law and policy.

The Institutes of Justinian, by contrast, is an introductory textbook modelled on the Institutes of Gaius. It was promulgated as statute in AD 533, the same year as the Digest, and carries the force of imperial law. Shorter and more systematic than the Digest, the Institutes provide an accessible entry point, but they simplify and occasionally distort the classical sources.

By the classical period, delictual liability had become an arena for sophisticated legal reasoning. The jurists debated the mental element required for furtum (did it require intent to deprive permanently or merely to use?), the scope of the lex Aquilia (could it cover indirect causation?), and the proper measure of damages. Their methods—close textual interpretation, reasoning by analogy, and principled distinction of cases—are the methods you will practice in tutorials.

It is essential to remember that Roman law was not uniform across time or place. The sources you read are translations (most Oxford students work from the Latin-English Digest of Mommsen-Krueger or the Scott translation, and the Institutes of Birks & McLeod or Thomas). Sensitivity to translation choices, awareness of interpolations, and a historian's caution about anachronism are all necessary skills. The Rome of Gaius differed markedly from that of Justinian, and both differ from the modern legal imagination.

The nature of delictual liability

Roman delict imposed liability for a limited set of nominate wrongs. Unlike the modern law of tort, there was no general principle that 'harm wrongfully caused gives rise to liability'. Instead, a plaintiff had to bring his case within one of the recognised categories. If no existing actio fitted, the praetor might grant an analogous remedy (actio utilis or actio in factum), but this was discretionary and exceptional.

Delictual actiones were penal, not compensatory, in their primary character. The successful plaintiff recovered a multiple of the loss (double, triple, or even quadruple) or a sum fixed by the judge according to equitable considerations (quanti ea res erit). The poena was payable to the victim, not the state, but it served deterrent and punitive functions akin to modern criminal sanctions. This dual character—private enforcement of what we might consider public wrongs—reflects the different boundary between public and private law in Rome.

Delictual liability was strictly personal. The action lay against the wrongdoer alone, and (with limited exceptions) did not pass to or against heirs. The principle actio poenalis haeres non habet meant that if the wrongdoer died before judgment, the action was lost. This contrasts with contractual claims, which generally did pass to heirs. However, if the wrongdoer's estate had been enriched (for instance, by stolen property), a restitutionary claim (condictio) could lie against the heir.

Classification and remedies

The Institutes (IV.1 pr.) state that obligations arise aut ex contractu aut ex delicto—either from contract or from delict. Later jurists recognised a third category, quasi ex contractu and quasi ex delicto (obligations arising as if from contract or delict), but the fundamental binary structure persisted.

Each delict had its own actio. For furtum, the actio furti lay for double the value of the thing stolen (or quadruple for furtum manifestum, theft detected in the act). For iniuria, the actio iniuriarum allowed the judge to assess damages flexibly according to the gravity of the affront. For damnum iniuria datum under the lex Aquilia, the measure was the highest value of the thing in the preceding year (chapter 1) or thirty days (chapter 3), a formula that could yield a penalty exceeding simple loss.

Roman law did not operate on a system of binding precedent, but the responsa (opinions) and writings of the classical jurists functioned analogously, providing authoritative guidance on disputed points. The excerpts preserved in the Digest are the closest Roman law comes to 'landmark cases', and mastery of key texts is essential.

D.9.2.27.14 (Ulpian, Ad Edictum 18): The colliding ships

Ulpian discusses a scenario in which two ships collide. If the collision occurred through the fault (culpa) of the sailors, an action under the lex Aquilia lies. If it occurred through irresistible force (e.g., a sudden storm), no liability attaches. This text illustrates the centrality of fault and the requirement of causal connection. It also exemplifies the casuistic method: Ulpian works through a concrete hypothetical, teasing out principles applicable to analogous situations.

D.47.2.52.20 (Ulpian, Ad Edictum 37): Use-theft (furtum usus)

This fragment addresses whether one who uses another's property beyond the scope of permission commits furtum. Ulpian gives the example of a borrower (commodatarius) who uses a horse lent for a journey for a different purpose. The conclusion: such use constitutes furtum usus, a distinct species of theft. The reasoning turns on the absence of the owner's consent (invito domino) and the intent to gain a benefit at the owner's expense (animus furandi).

The text is foundational for understanding furtum as extending beyond simple taking to unauthorised use. It also demonstrates the importance of consent and the subjective mental element.

D.9.2.11.2 (Ulpian, Ad Edictum 18): Causation and the starving slave

Ulpian reports a debate: if A locks B's slave in a room and the slave starves to death, has A killed the slave within the meaning of lex Aquilia chapter 1? Ulpian notes division of opinion. Some jurists held that A did not kill corpore suo (by bodily act), because the death resulted from the omission to feed, not a positive act. Others argued that locking the door was sufficient causal connection. The text highlights the interpretative difficulty surrounding direct causation and presages centuries of debate on omissions and indirect harm.

D.47.10.1.1 (Ulpian, Ad Edictum 56): The nature of iniuria

Ulpian defines iniuria broadly: it consists in contempt (contumelia) shown to another, either in deed or in word. It includes physical assault, defamation, and affront to dignity. The scope is not limited to bodily harm; insult and indignity suffice. Ulpian emphasises that iniuria may be committed against one's body, dignity, or reputation, reflecting the Roman concern with honour (dignitas).

This text is central to grasping iniuria as a delict of affront rather than mere physical harm, and it foreshadows the civilian tradition's treatment of personality rights.

D.47.2.50.4 (Paul, Ad Edictum 39): Mistake and furtum

Paul considers whether one who takes another's property believing it to be his own commits furtum. He concludes that there is no theft, because the requisite intent (animus furandi) is absent. The thief must intend to gain at another's expense; mere mistake negatives this intent. The text underscores the subjective requirement and its role in limiting liability.

D.9.2.52.1 (Alfenus, Digest 2): The falling branch

Alfenus discusses a case in which a man pruning a tree shouts a warning, but a falling branch nevertheless kills a passing slave. Is the tree-pruner liable under the lex Aquilia? Alfenus holds that if the pruner gave adequate warning, there is no culpa and hence no liability. The text establishes that reasonable precaution negatives fault, adumbrating the modern standard of care.

These texts are not 'cases' in the common-law sense—there are no named parties, no adversarial trial records—but they are the functional equivalent: authoritative analyses of paradigm situations that shape doctrine. You should be able to cite them by Digest reference, explain their reasoning, and apply their principles to novel facts.

See practice questions below.

See further reading below.