Definition
Ususfructus (also rendered usufruct in modern usage) is a civil law property right entitling a person to use another's property and to take its fruits or profits, provided the substance of the property itself is not diminished or destroyed. The holder of the right — the usufructuary — may occupy land, collect rents, harvest crops, or receive income generated by the property, but may not consume, alienate, or fundamentally alter the underlying thing. Ownership remains with the original proprietor; what is transferred is only the use and enjoyment.
The right is inherently tied to the physical existence of the subject matter: if the thing is destroyed, the ususfructus is extinguished with it. It is also typically personal in character, most commonly granted for the life of the usufructuary or for a fixed term, after which full enjoyment reverts to the owner.
Common Confusion
Ususfructus is frequently conflated with two narrower Roman law concepts from which it is distinguished: usus (the right of use alone, without taking fruits beyond personal needs) and habitatio (the right to dwell in another's house). Ususfructus is the broadest of the three personal servitudes in classical civil law, encompassing both use and the taking of profits. It is also sometimes confused with a lease or license, but differs fundamentally: a lease is a contractual obligation running between parties, while ususfructus is a real right — a right in the thing itself, enforceable against the world.
Core Elements
The classical definition requires three elements, all of which must be present:
1. A corporeal subject: The right attaches to a physical thing. Roman jurists debated whether consumable goods could support a true usufruct (the quasi-usufruct emerged as the solution for fungibles, requiring restitution of equivalent goods rather than the same items).
2. Use and enjoyment of fruits: The usufructuary is entitled to natural fruits (crops, offspring of animals) and civil fruits (rents, interest) produced by the thing during the term of the right.
3. Preservation of substance (salva rerum substantia): The defining limit. The usufructuary must return the thing in essentially the same condition, ordinary wear excepted. Transformation, exhaustion, or destruction of the subject matter breaches this condition and ends the right.
Why It Matters in Research
Researchers encounter ususfructus most heavily in three contexts: Roman and civil law primary sources, Louisiana and Quebec private law materials, and comparative law scholarship addressing the reception of civil law concepts in common law jurisdictions.
In Roman law sources, the term appears in the Institutes and Digest with technical precision that later civilian commentators elaborated at length. Researchers working in post-classical or medieval civil law materials should note that the doctrine was refined, and distinctions between perfect and imperfect usufruct (the quasi-usufruct) became important — a distinction Burrill's entry gestures toward but does not fully develop.
In American research, Louisiana is the critical jurisdiction. Louisiana's Civil Code preserves usufruct as an operative legal concept with ongoing case law. Researchers treating usufruct in common law states will find only analogical usage — courts sometimes describe life estates or trust income interests in usufruct terms, but the formal Roman right has no independent existence in common law property doctrine.
A navigational trap in historical sources: older English legal dictionaries and some treatises use usufruct loosely to describe any life estate or income interest. This is analogical borrowing, not a claim that the civil law institution was received. Distinguish carefully between descriptive usage and technical civil law doctrine.
Corpus researchers should also be alert to the quasi-usufruct, which appears in French and Louisiana materials and functions differently from the parent concept — it applies to consumables and requires restitution of equivalent value rather than the thing itself.
Historical Dictionary Support
Burrill's entry is technically sound and concise. It correctly identifies the two-part Roman formulation — jus utendi fruendi (right of use and enjoyment) and the salva rerum substantia limitation — and cites the Institutes (2.4) as authority. The entry captures the essential civilian definition accurately for its period.
What Burrill does not address: the personal servitude classification (distinguishing ususfructus from servitudes running with land), the quasi-usufruct problem for fungible goods, or the procedural mechanisms by which a usufructuary gave security (cautio usufructuaria) for proper use. For researchers needing those dimensions, Burrill's entry is a starting point only. Civilian encyclopedists such as Domat and Pothier, and Justinian's Digest (7.1), provide fuller treatment. In the American context, Louisiana Civil Code articles on usufruct (Articles 535 et seq.) represent the operative reception of the doctrine.
Jurisdictional Note
Ususfructus as a formal legal right exists in Louisiana and Quebec as operative private law, derived from French and Spanish civil law reception. In common law jurisdictions, the concept has no technical legal standing, though courts and commentators occasionally use "usufruct" descriptively. Researchers should not assume that judicial use of the term in a common law jurisdiction signals adoption of the civilian doctrine.