Definition
Not susceptible of division or apportionment; entire; inseparable as a legal or contractual matter. In law, indivisible describes an obligation, contract, consideration, injury, or cause of action that must be treated as a single, unified whole rather than broken into independently enforceable or compensable parts.
The concept appears most consequentially in two contexts:
1. Indivisible contracts. A contract is indivisible when full performance of every part is a condition precedent to the other party's obligation to perform. The parties' promises are so intertwined that partial performance does not bind the other side pro tanto — the contract stands or falls as a unit. This contrasts with a divisible contract, where the agreement can be apportioned into independent segments, each capable of generating its own rights and remedies.
2. Indivisible injuries and causation. In tort law, an injury is indivisible when it cannot be apportioned among multiple tortfeasors because the harm itself — not merely the wrongdoing — is inseparable. Where two or more defendants contribute to a single indivisible injury, courts typically impose joint and several liability rather than attempting to allocate distinct shares of damage.
Common Language
Modern common usage (Wiktionary): "That which cannot be divided or split."
Historical common usage (Webster's 1913): "Not divisible; incapable of being divided, separated, or broken; not separable into parts."
The ordinary meaning and the legal meaning are closely aligned in the abstract, but the legal term carries significant technical consequence that the common definition does not capture. In everyday language, indivisible is a descriptive quality. In law, characterizing an obligation or injury as indivisible triggers specific doctrinal outcomes — on the contract side, the all-or-nothing performance rule; on the tort side, joint and several liability among concurrent tortfeasors. The stakes of the classification, not the word itself, are what make the legal usage distinct.
Common Confusion
Indivisible is frequently contrasted with divisible, and the two terms are sometimes treated as self-evident opposites when in practice the line between them is one of the more contested determinations in contract law. Courts applying different tests — whether the consideration can be apportioned, whether the parties' intent supports segmentation, whether partial performance has conferred measurable benefit — often reach inconsistent results on identical fact patterns. Researchers should not assume that a contract labeled "entire" in older sources is equivalent to indivisible in the modern sense; "entire contract" is the historical precursor term and the doctrinal framing has shifted.
Why It Matters in Research
The term does significant work in two largely separate bodies of doctrine — contract law and tort causation — and historical sources tend to treat only one or the other without cross-referencing the other context. A researcher following indivisible through contract treatises may miss its parallel development in multi-defendant tort cases, and vice versa.
In contract research, the indivisible/divisible distinction was outcome-determinative under common law's strict forfeiture rules. A breaching party on an indivisible contract recovered nothing in quantum meruit at common law, whereas a breaching party on a divisible contract could recover for segments already performed. Modern courts and the Restatement approach have softened this through substantial performance and restitution doctrines, so older dictionary entries overstating the harshness of the indivisible rule should be read with caution.
In tort research, the indivisible injury concept is the doctrinal foundation for joint and several liability in concurrent-tortfeasor cases. Many states have modified or abolished joint and several liability by statute since the 1980s, meaning the practical consequences of an indivisible injury finding vary substantially by jurisdiction and era. Historical sources written before those reforms will not reflect the current landscape.
The second edition of Black's entry nominally filed under this term actually contains text about "indirect" and unrelated domestic relations cases — a known editorial artifact of that edition. Researchers using the 2nd edition in digitized form should verify that retrieved text actually corresponds to the headword.
Historical Dictionary Support
The first edition of Black's Law Dictionary offers the clearest and most useful historical entry: indivisible means not susceptible of division or apportionment; inseparable; entire, with the contract as the paradigm example. Bouvier's extends this usefully into the breach-of-contract consequences, articulating the condition-precedent logic that underlies the entire/indivisible framework — that the performance of every part binds the other party, whereas divisible parts bind pro tanto. Anderson's cross-references without adding independent content.
The historical sources agree on the core meaning but share a common gap: none addresses the tort causation usage, which developed as a distinct doctrinal application in the late nineteenth and twentieth centuries and is now the context in which indivisible is most frequently litigated. Researchers relying solely on historical dictionaries will have an incomplete picture of the term's operational range.
Jurisdictional Note
The tort law application of indivisible injury is highly jurisdiction-sensitive. States that have enacted proportionate liability reforms or abolished joint and several liability have altered what follows from an indivisible injury finding. The contract law application is more uniform in principle but varies in how courts draw the divisible/indivisible line in practice, particularly in construction, employment, and installment-payment contexts.