Definition
Lucrum cessans (Latin: "ceasing gain") is a civil law concept denoting the profit or gain that a party has lost as a consequence of another's wrongful act or breach of contract. It represents prospective or foregone profit — what the injured party would have earned but did not — as distinct from an actual out-of-pocket loss already suffered.
The term operates in contrast to two companion concepts: damnum emergens (or damnum datum in Scots law usage), which refers to positive loss actually sustained, and, in the context of contract breach, the non-payment of money, which was ordinarily addressed through interest rather than damages. Together, lucrum cessans and damnum emergens form the classical civil law framework for measuring recoverable loss: the first looking to what was not gained, the second to what was directly taken away or destroyed.
In practical terms, lucrum cessans maps closely onto what modern common law calls lost profits or consequential damages — the economic opportunity cost of the wrong.
Common Confusion
Lucrum cessans is frequently paired with, and sometimes confused against, damnum emergens and damnum datum. These are not synonyms but complementary categories:
— Damnum emergens: positive, actual loss already incurred (e.g., property destroyed, money paid out).
— Damnum datum: the Scots law equivalent of damnum emergens — actual harm done.
— Lucrum cessans: the gain that ceased to accrue — profit that would have been received but was prevented.
In some civil law sources the pair is rendered as damnum emergens / lucrum cessans; in Scots law sources it appears as damnum datum / lucrum cessans. Researchers should not treat these pairings as inconsistent — they reflect the same conceptual division across different jurisdictional traditions.
Why It Matters in Research
The primary research risk with lucrum cessans is anachronism: reading modern lost-profits doctrine backward into historical sources, or reading historical civil law doctrine forward into modern common law cases, without accounting for significant conceptual and procedural gaps.
In civil law systems, lucrum cessans was a recognized, formal head of damage recoverable in contract actions — but with important limitations. Bouvier notes that damages for lucrum cessans were recoverable "in particular cases," not universally. The rules governing which cases permitted recovery of foregone profits were considerably more restrictive than modern common law consequential damages doctrine, and researchers examining historical civil law sources should not assume that acknowledgment of the concept implies broad recoverability.
In Scots law, the term appears in conjunction with damnum datum and carries equitable overtones traceable to Lord Kames. Researchers using Scots sources should be alert to the equity/law divide in Scottish jurisprudence and to the fact that Kames' treatment of the concept is embedded in his broader theory of reparation, not in a purely contractual framework.
For common law researchers, lucrum cessans rarely appears in English or American case law by name. Where it does appear, it is typically in cases with a civil law dimension — admiralty, maritime, Louisiana, Quebec, or cases engaging Roman law principles. Its functional equivalent in modern common law doctrine is the lost profits component of expectation damages, but that equivalence should be stated carefully: the civil law framework imposed different limitations on foreseeability, certainty, and the type of contract involved.
The companion maxim appearing in Black's — Lucrum facere ex pupilli tutela tutor non debet ("a guardian ought not to make money out of the guardianship of his ward") — is entirely unrelated to lucrum cessans as a damages concept. It appears in close proximity in several historical dictionaries only because of alphabetical arrangement. Researchers should not read any doctrinal connection between the two.
Historical Dictionary Support
The historical dictionaries are in broad agreement on the core meaning but diverge in emphasis and context.
Black's (both editions) and Burrill situate lucrum cessans specifically within Scots law, defining it as "a ceasing gain, as distinguished from damnum datum, an actual loss." Burrill cites Kames' Equity as authority, grounding the concept firmly in Scottish equitable jurisprudence.
Bouvier takes a wider view, placing the term in civil law generally rather than Scots law in particular. His entry is more practically oriented: lucrum cessans is "the amount of profit lost as distinguished from damnum emergens, an actual loss," and he specifies that it covered losses from contract breach "other than the mere non-payment of money" (which was addressed by interest). Bouvier notes both heads of loss could be recovered in appropriate cases, citing Howe's Studies in Civil Law — a more practical framing than Black's or Burrill's more definitional approach.
What the historical dictionaries do not address: the significant doctrinal limits on recovery of lucrum cessans in classical civil law (requirements of certainty, directness, and foreseeability), the relationship to the modern civil law concept of perte de chance (loss of a chance), or any systematic treatment of how English equity courts engaged with the concept. Researchers requiring substantive doctrinal depth will need to go beyond dictionary sources to civilian treatises and Scots institutional writers.
Jurisdictional Note
Lucrum cessans remains a live term of art in civilian jurisdictions, including Louisiana, Quebec, and most continental European legal systems, where it appears in statutory and judicial frameworks for calculating damages. In common law jurisdictions it is primarily a historical and comparative law term. Mixed jurisdictions are the most likely context in which a researcher will encounter it in operative legal documents.