Definition
Argentum Dei (Latin: "God's money") is a historical common law term for earnest money — a sum paid at the moment of striking a bargain to signal that the parties intend to be bound. The payment functioned as a token of mutual commitment rather than as part of the purchase price itself. Its synonym, *denarius Dei* ("God's penny"), reflects the same concept and appears interchangeably in the old sources.
Common Confusion
Argentum Dei and denarius Dei are the same concept. Researchers should not treat them as meaningfully distinct. The variation in terminology reflects regional and period usage rather than any difference in legal function or effect. Both terms should be searched when tracing the history of earnest money or contract formation practices in early English legal records.
Do not conflate argentum Dei with the modern legal concept of consideration. Earnest money in the modern sense functions within a developed doctrine of contract formation; argentum Dei predates that doctrine and operated in a different normative environment where the quasi-religious character of the payment carried independent weight.
Why It Matters in Research
This term appears almost exclusively in pre-modern English legal materials. Researchers encountering it in medieval or early modern records, manuscript sources, or antiquarian commentaries on statute should understand it as an early analogue to the modern doctrine of earnest money or nominal consideration — not as a distinct surviving legal concept. The term will not appear in modern pleadings or statutes.
The connection to *denarius Dei* is the critical cross-reference: the two terms describe the same practice, and sources use them interchangeably without always flagging that equivalence. Failing to search both terms in a historical corpus risks missing relevant material. Burrill explicitly directs the reader to *denarius Dei*, and researchers should follow that lead.
The broader relevance is to the history of contract formation. Argentum Dei represents an early mechanism for signaling binding intent at a time when formal doctrines of consideration were undeveloped. It sits at the intersection of ecclesiastical influence on commercial practice — the invocation of God's name on a penny or coin carried a quasi-sacramental weight that reinforced the obligation. This context matters when reading historical commentary that discusses whether and how such payments created enforceable obligations under early common law or canon law frameworks.
Barrington's Observations on the Statutes, cited by Burrill, is the secondary source most likely to contextualize this term within Anglo-Saxon and early Norman commercial practice. Cowell's Interpreter, cited by both Black's and Burrill, is the primary historical dictionary source and the appropriate starting point for further antiquarian research.
Historical Dictionary Support
Black's Law Dictionary and Burrill's Law Dictionary are in full agreement: both define argentum Dei as earnest money given upon the making of a bargain, both cite Cowell as authority, and both equate the term with its synonym denarius Dei. Burrill's entry is the more developed of the two, adding the Petyt manuscript reference via Barrington and making the cross-reference to denarius Dei explicit.
Neither dictionary attempts to distinguish argentum Dei from its synonym in any legally operative way — the distinction appears to be purely linguistic (silver/money vs. penny), not doctrinal. Historical dictionaries treat this as an antiquarian curiosity rather than a term requiring careful legal parsing, which accurately reflects its status in the sources.
What the historical dictionaries do not address is the underlying legal question of what effect, if any, the payment of argentum Dei had on enforceability of the underlying bargain under early common law. That question requires research beyond the dictionary sources and into the medieval legal and ecclesiastical literature.