Definition
In solidum; jointly and without division. A term from the civil law tradition describing an obligation or right held as a whole — undivided — rather than apportioned among multiple parties. Where parties hold a right or bear a liability *in solide*, each is bound or entitled to the full amount, not merely a fractional share. The term appears most often in discussions of solidary obligation, where any one obligor may be compelled to satisfy the entire debt, and any one creditor may demand full performance, regardless of the number of parties on either side of the obligation.
Common Confusion
INSOLIDE / IN SOLIDUM / SOLIDARY / JOINT AND SEVERAL: These terms describe the same underlying concept through different terminological traditions. *In solide* and *in solidum* are Latin-rooted civil law expressions; "solidary obligation" is the civilian doctrinal term carried into Louisiana and Scots law; "joint and several liability" is the common law equivalent. Researchers moving between civil law sources and common law sources will encounter all four phrasings for what is functionally the same rule. Conflating "joint" liability (where each party owes only a proportionate share) with "joint and several" or solidary liability (where each owes the whole) is a persistent error — the distinction is the entire point of the term.
Why It Matters in Research
This is a term of art from the civilian tradition that surfaces primarily in sources rooted in Roman law, canon law, and legal systems with civilian inheritance — Louisiana, Quebec, Scotland, and the mixed jurisdictions. Researchers working in early American legal sources should be alert to the following:
First, the spelling and presentation vary. *In solide*, *insolide*, *in solidum*, and *in solidis* appear interchangeably across historical sources, sometimes within the same document. Keyword searching in corpus materials requires casting a wide net.
Second, the term carries precise technical weight that its appearance may not signal. A deed, bond, or contract reciting that parties are bound *in solide* is not merely adding emphasis — it is specifying the structural form of the obligation and foreclosing pro-rata defenses.
Third, in Louisiana legal materials — the most heavily civilian American jurisdiction — solidary obligation governed by *in solide* principles is codified doctrine with a continuous history from the Digest of 1808 forward. Corpus researchers comparing pre- and post-codification Louisiana sources will find the Latin phrase retreating as French and then English civilian vocabulary takes over, but the underlying rule persists.
Fourth, in common law jurisdictions, this term is largely absent from primary sources. When it does appear, it is typically in treatises translating civilian doctrine for common law audiences, or in equity proceedings involving parties with civilian-law connections. Its presence in a common law document is itself a signal worth investigating.
Historical Dictionary Support
Burrill's entry is spare — "solidly; without any separation of possession or ownership" — but it accurately captures the structural core: the absence of division. The phrase "without separation of possession or ownership" usefully extends the concept beyond pure obligation into property contexts, where co-owners might hold *in solide* as an undivided whole rather than in defined shares.
Burrill does not address the distinction between active solidarity (creditors' side) and passive solidarity (debtors' side), nor does he engage the Roman-law sources from which the term derives. Researchers seeking deeper doctrinal treatment will find more in civilian-tradition dictionaries and in treatises on Louisiana or Scots law than in common law dictionary sources. The absence of robust coverage in English-language legal dictionaries reflects the term's limited penetration into common law practice rather than any ambiguity in its meaning within civilian systems.
Jurisdictional Note
The term has living doctrinal significance primarily in Louisiana, where solidary obligations remain a distinct category of positive law. In common law jurisdictions, the concept is fully absorbed into joint and several liability doctrine, and the Latin phrase is rarely used. Scottish legal sources use "joint and several" and "solidary" interchangeably in ways that can confuse researchers trained in either tradition alone.