Definition
Res mobiles (Latin: "movable things") is a civil law term designating property that can be transported from one place to another without damage to its substance or physical form. The category encompasses all tangible personal property capable of physical relocation — tools, goods, livestock, currency, and similar items. In the civil law tradition, res mobiles stands in contrast to res immobiles (immovable things, chiefly land and structures attached to it).
The common law functional equivalent is chattels personal — personal property held in possession, as distinguished from real property or chattels real. The correspondence is approximate rather than exact, as the civil law and common law systems developed distinct taxonomies for classifying property, but courts and commentators have consistently treated the two categories as broadly parallel.
Common Confusion
Res mobiles is sometimes loosely equated with personal property generally, but the category is properly limited to movable tangibles. Intangible rights — choses in action, intellectual property, negotiable instruments — are not res mobiles in the strict civil law sense, even though they may qualify as personal property or chattels under common law. The distinction matters most when a researcher is working with sources that apply civil law property concepts directly, as in Louisiana jurisprudence or in scholarship drawing on Roman law foundations.
Res mobiles should also be distinguished from res mancipi and res nec mancipi, the older Roman law division based on the formality required for transfer, which cuts across the movable/immovable line and appears in earlier historical sources.
Why It Matters in Research
The term surfaces primarily in three contexts: (1) civil law jurisdictions and mixed legal systems, especially Louisiana, where the civil law property taxonomy was incorporated into American law; (2) comparative law scholarship that traces the parallel development of civil and common law property categories; and (3) older treatises and digests where Roman law concepts were used to organize American and English property doctrine.
Researchers working in Louisiana property law will encounter res mobiles (and its statutory descendant, "movables") as operative legal vocabulary, not merely historical reference. Louisiana's Civil Code distinguishes movables from immovables in ways that do not map cleanly onto common law real property / personal property distinctions, so a researcher assuming the categories are interchangeable can easily misread primary sources.
In non-Louisiana contexts, the term appears most often in treatises — Kent's Commentaries, Mackeldey's Civil Law, Story's Conflict of Laws — where authors used civil law vocabulary to build a systematic framework for American property doctrine. When tracking a common law concept back through these treatises, recognizing res mobiles as the civil law referent for chattels personal prevents confusion about the analytical tradition being invoked.
The choice-of-law dimension is also relevant. Historical conflict-of-laws doctrine treated the law governing transfer of res mobiles differently from immovable property: movables were generally governed by the law of the owner's domicile (lex domicilii), while immovables were governed by the law of the situs (lex situs). Sources invoking res mobiles in a choice-of-law context are engaging that specific doctrine, not simply describing what kind of property is at issue.
Historical Dictionary Support
Black's and Burrill's entries are substantively identical, both citing Kent's Commentaries (2 Kent, Comm. 347) for the common law correspondence and Mackeldey's Civil Law for the civil law definition. The convergence is unsurprising — both dictionaries drew heavily on the same treatise sources, and for a foundational civil law term this settled, there was little reason to diverge.
Both entries define the category by its functional characteristic (capacity for transport without injury to substance and form) rather than by enumeration. This functional definition has the advantage of being technology-neutral — it applies equally to a Roman-era ox and a nineteenth-century piece of machinery — but it creates interpretive edge cases for items that can be moved only with difficulty or partial damage. Historical sources do not resolve these edge cases systematically.
Neither entry addresses intangibles, semi-movables, or the Louisiana statutory codification, reflecting the period in which these dictionaries were compiled. Researchers applying the term to modern contexts, particularly in Louisiana, should consult the Louisiana Civil Code directly rather than relying solely on these historical dictionary formulations.
Jurisdictional Note
Louisiana is the primary American jurisdiction where res mobiles functions as operative legal vocabulary. The Louisiana Civil Code uses "movables" as the statutory term, but the underlying civilian concept is continuous with the Roman law category. In all other American states, the term is historical or comparative in function; common law jurisdictions use chattels personal or personal property instead.
Encyclopedia Cross-Reference
The Law Mind Torts & Personal Injury Encyclopedia: Negligence — Res Ipsa Loquitur (Inference of Negligence) — shares the res prefix and Latin-derived terminology but is otherwise unrelated; do not conflate.
No Law Mind Encyclopedia entry directly addresses civil law property taxonomy or Louisiana movables doctrine. Researchers should consult the encyclopedia entries on Property Classification and Conflict of Laws if available in the corpus.