Definition
De æstimato (also rendered de aestimato) is a Roman law contract belonging to the category of innominate contracts — agreements that did not fit neatly within the classical named contracts of Roman private law. In a de æstimato arrangement, property (land or goods) was delivered to a third party at a fixed, agreed valuation. That third party undertook to either sell the property and return the proceeds, or, if a sale could not be completed, to return the property itself or pay the fixed price. The guarantor's obligation to secure a buyer — or to stand personally liable for the agreed price — was the defining feature that distinguished this arrangement from a straightforward consignment or agency relationship.
In functional terms, de æstimato operated something like a guaranteed consignment: the owner fixed the price, the intermediary accepted delivery, and the risk of failing to achieve a sale fell on the intermediary rather than the owner.
Common Confusion
The term is frequently misspelled or misread in older sources. The correct Latin root is æstimatio (valuation or appraisal), from which æstimato derives. Variants appearing in secondary literature — including "zstimato," "estimato," and "aestimato" — all refer to the same instrument. Researchers encountering any of these forms in historical legal texts are looking at the same concept.
De æstimato should not be confused with the actio de æstimato, which was the specific Roman law action available to enforce the contract when the intermediary failed to perform. The contract and the action arising from it are related but distinct concepts.
Why It Matters in Research
De æstimato is primarily a Roman law term and will appear in research contexts involving civil law history, comparative law, and the doctrinal origins of modern commercial arrangements such as consignment and guarantee contracts. Researchers working in the Law Mind corpus should be alert to several navigational challenges.
First, spelling variation is significant. Because the æ ligature did not survive reliably into early modern printing, historical sources render this term inconsistently. A search limited to one spelling will miss instances using another. Corpus searches should account for "aestimato," "estimato," "de aestimato," and variant hyphenated or spaced forms.
Second, the innominate contract category itself requires context. Roman jurists classified contracts as nominati (named, with established actions) or innominati (unnamed, enforceable on the basis of performance rendered). De æstimato sat in the innominate category alongside do ut des, do ut facias, and facio ut facias. Understanding this classification is essential to understanding why Roman sources treat de æstimato as it does — the absence of a formal name meant the available remedies and the doctrinal analysis differed from named contracts like sale (emptio venditio) or hire (locatio conductio).
Third, researchers tracing the genealogy of modern commercial law doctrines — particularly consignment, del credere agency, and guarantee — may find de æstimato cited as a historical precursor. The del credere agent in modern commercial law (an agent who guarantees the creditworthiness of buyers to the principal) bears a structural resemblance to the de æstimato intermediary, and some comparative law sources draw this connection explicitly.
Historical Dictionary Support
Black's Law Dictionary (2nd Ed.) provides the primary entry available in the Law Mind corpus. Black's correctly situates de æstimato among the innominate contracts and identifies its core mechanism: delivery at a fixed price (æstimato) with a third-party guarantor undertaking to find a purchaser. This is an accurate and compact account.
What Black's does not address — and what researchers should supply from Roman law primary sources and civilian commentators — is the procedural dimension: the actio de æstimato was the remedy available when the intermediary defaulted. Black's also does not address the doctrinal debate among Roman jurists about whether de æstimato was more properly analogized to sale or to mandate, a question that had practical consequences for the remedies available to both parties.
No entry for this term appears in the other standard historical law dictionaries commonly encountered in comparable research collections. Its relative obscurity in the English common law tradition reflects the fact that de æstimato is a concept of Roman and civil law, with limited direct doctrinal presence in common law jurisdictions.
Jurisdictional Note
De æstimato has no direct operative legal significance in modern common law jurisdictions. Its relevance is historical and comparative. Civil law systems with Roman law foundations — including French, Italian, Spanish, and Louisiana law — are more likely to contain doctrinal traces of the concept, though modern civilian codes have generally absorbed its functions into named commercial contracts.
Encyclopedia Cross-Reference
The Law Mind Business Organizations & Corporate Law Encyclopedia: Corporate Formation — Defective Incorporation (De Facto, Corporation by Estoppel) [business_41] — useful for researchers encountering "de facto" terminology in the same Roman-derived doctrinal register, though the substantive overlap is limited.