Definition
A Latin maxim meaning "I give that you may give" or "I give [to you] so that you may give [to me]." In Roman and civil law, do ut des identified one of four recognized categories of innominate contracts — agreements that did not fit neatly into the classical named contract forms (such as sale or hire) but were nonetheless enforceable because one party had already performed. The do ut des class covered exchanges in which one party transferred property or a thing of value in consideration of the other party transferring property or a thing of value in return. It is, in essence, the civil law's way of describing a barter or exchange transaction reduced to its elemental form: performance-for-performance, thing-for-thing.
The four innominate contract categories in Roman law were:
- Do ut des (I give that you may give)
- Do ut facias (I give that you may do)
- Facio ut des (I do that you may give)
- Facio ut facias (I do that you may do)
Do ut des is the simplest and most foundational of the four.
Common Language
This is Latin legal terminology with no meaningful common English counterpart. The phrase does not appear in general usage. The words themselves translate directly and require no separate treatment. COMMON LANGUAGE section is omitted.
Common Confusion
Do ut des is sometimes loosely equated with the common law concept of consideration, and Bouvier's directs readers there without further elaboration. The connection is real but imprecise. Consideration in common law is a broader doctrinal framework concerned with whether a promise is legally binding; do ut des describes a specific structural form of completed exchange within the civil law's taxonomy of contracts. The civil law innominate contract categories were concerned primarily with classifying obligations that had already been partially performed — the classification triggered enforcement of the counter-performance. Common law consideration doctrine, by contrast, operates at the moment of promise formation, not after partial performance. Researchers should not treat the two as synonymous.
Why It Matters in Research
Do ut des appears most frequently in sources dealing with Roman law, civil law jurisdictions, or comparative legal history. In American and English common law research, it surfaces almost exclusively in historical treatises and older encyclopedias as background for explaining the nature of consideration or contractual exchange — not as operative legal doctrine.
Several research traps exist. First, the term appears in Blackstone (2 Bl. Comm. 444), which is the bridge text that carried civil law vocabulary into early Anglo-American legal writing. Researchers encountering do ut des in early American or colonial-era sources are almost always looking at Blackstone's influence, not direct civil law borrowing. Second, Bouvier's compressed treatment — simply redirecting to consideration — reflects the nineteenth-century American tendency to absorb civil law concepts into common law categories rather than preserve them as distinct doctrines. A researcher who follows Bouvier's cross-reference without understanding the civil law context will miss the structural difference. Third, in Louisiana, Quebec, and other mixed or civil law jurisdictions, the innominate contract categories had continuing doctrinal relevance well past the point where they had become purely historical in common law states. Corpus searches in Louisiana legal materials will yield different results than searches in Massachusetts or Virginia sources.
Historical Dictionary Support
Black's Law Dictionary (both the first and second editions) gives substantively identical definitions, translating the phrase and situating it within the civil law taxonomy of innominate contracts. The second edition adds the Digest citations (Dig. 19, 4; Dig. 19, 5, 5) and the Blackstone reference, which are genuinely useful for researchers tracing the concept's transmission into Anglo-American legal writing. Bouvier's treats the term with minimal engagement, offering only the translation and a redirect to consideration — a compression that, while efficient, loses the civil law structural context entirely.
None of the historical dictionaries draw out the distinction between do ut des as a classification device and consideration as a doctrinal test, which is the most practically important analytical gap for a researcher trained in common law.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Innominate Contracts; Consideration — Historical Development.