Definition
In Latin legal usage, *aut* means "or" — the disjunctive conjunction. It appears throughout Roman law texts, particularly in the Digest, and carries interpretive weight in contexts where the choice between disjunctive ("or") and conjunctive ("and") reading of a legal instrument determines the scope of an obligation, grant, or right.
The classical Roman jurists recognized that *aut*, though grammatically disjunctive, could in certain legal contexts be read conjunctively — that is, as equivalent to *et* ("and"). The operative principle was *disjuncta pro conjunctis accipiantur*: disjunctive terms may be taken as conjunctive. Thus the formula *dedi aut donavi* ("I gave or I donated") was construed to embrace both acts, not merely one to the exclusion of the other. The point was not that *aut* changed its meaning, but that the law looked to what the speaker intended to include, not merely to formal grammatical structure.
Common Language
Modern common usage (Wiktionary): *AUT* as a modern term appears almost exclusively as an initialism — Auckland University of Technology, American University of Technology, Association of University Teachers, and similar. It carries no independent meaning in modern English.
Historical common usage: The Latin *aut* entered medieval legal writing directly as a functional word, not a term of art. In classical Latin, *aut* was the strong disjunctive — "either...or" in a mutually exclusive sense — distinguishing it from *vel*, the weaker or inclusive disjunctive.
The gap between modern and legal usage here is total: the modern initialism *AUT* and the Latin legal term *aut* are unrelated. Researchers encountering *aut* in Latin legal texts and Digest citations should treat it as Latin vocabulary, not an acronym.
Common Confusion
Two Latin disjunctives appear in Roman law sources and are frequently confused by researchers without Latin training:
*Aut* — the strong, exclusive disjunctive: "either A or B, but not both." In strict grammatical usage, it implies mutual exclusivity.
*Vel* — the weak, inclusive disjunctive: "A or B, or possibly both." This is the disjunctive of addition rather than exclusion.
The practical legal importance: when a Roman jurist used *aut* in drafting, the classical presumption leaned toward mutual exclusivity; when courts extended the *disjuncta pro conjunctis* rule, they were consciously overriding that presumption to serve the evident intent of the instrument. Missing this distinction leads to misreading the interpretive move the jurist was making.
Why It Matters in Research
Researchers working with Latin source texts in Law Mind — particularly Digest passages, Roman law treatises, and their common law or civil law descendants — need to recognize *aut* as a term with latent interpretive stakes. Several specific traps arise:
**The conjunctive/disjunctive problem in instrument construction.** The *disjuncta pro conjunctis* rule is not merely a Roman curiosity. It carried forward into civil law traditions and influenced common law rules of construction for deeds, wills, and contracts. When early modern English and American courts wrestled with the word "or" in instruments, they were often engaging, sometimes without knowing it, with the same analytical problem the Roman jurists addressed under *aut*/*vel*. Searching Law Mind's corpus for discussions of "or" and "and" in instruments will surface this lineage.
**Digest citations.** Burrill's entry cites Digest 50.16.53, a passage from the title *De verborum significatione* (On the meaning of words). This title is one of the richest sources in the Digest for rules of legal interpretation and is cited repeatedly in civil law commentary through the nineteenth century. Any Law Mind source citing Dig. 50.16 for a rule of construction is drawing on this tradition.
**Civil law codes.** Burrill notes a connection to the Louisiana Civil Code, reflecting how Roman interpretive rules passed through French and Spanish law into American civil law jurisdictions. Researchers tracing a rule of construction from Roman sources through Louisiana or Quebec materials should expect to encounter *aut* and its interpretive history as background doctrine.
**Latin literacy in historical sources.** Pre-twentieth-century legal dictionaries and treatises assume Latin literacy. Terms like *aut*, *vel*, *et*, and *seu* appear without translation in many sources. A researcher unfamiliar with the Latin disjunctive vocabulary may misread a passage about the scope of a grant or bequest.
Historical Dictionary Support
Burrill's Law Dictionary is the primary source for this entry. Burrill's treatment is compact but precise: he notes the disjunctive meaning, identifies the classical rule allowing conjunctive construction, quotes the Digest directly, and anchors the principle in *disjuncta pro conjunctis accipiantur*. This is characteristic of Burrill's method — he is more useful for locating the Roman law foundation of a principle than for tracing its common law applications.
What Burrill does not do is trace the reception of this rule into English or American common law. For that lineage, researchers should turn to treatises on the construction of wills and deeds, where the "or/and" substitution problem is treated extensively without the Latin framing.
The Latin dictionary confirms that *aut* as a strong disjunctive was the standard classical usage, with the conjunctive extension being a legal and interpretive gloss rather than an ordinary grammatical meaning.
Jurisdictional Note
The interpretive rule *disjuncta pro conjunctis accipiantur* has deepest roots in civil law jurisdictions. Louisiana courts have historically been more explicit in drawing on Roman law construction rules. Common law jurisdictions address the same problem through general rules of instrument construction but typically without citing the Roman source.
Encyclopedia Cross-Reference
Law Mind Encyclopedia — Civil Law Interpretation
Law Mind Encyclopedia — Rules of Construction (Wills and Deeds)
Law Mind Encyclopedia — Roman Law Sources in American Jurisprudence