Definition
An oath taken in ecclesiastical and canon law proceedings by which a party swore that the suit or claim being advanced was brought in good faith and not for purposes of vexation, harassment, or deceit. Closely related to — and in most sources treated as equivalent to — the calumniæ jusjurandum, calumniæ juramentum refers to the sworn assurance against malicious or frivolous litigation required of parties in the old canon law courts.
Common Confusion
Calumniæ juramentum and calumniæ jusjurandum are treated as functionally identical in the secondary literature and in Black's, but researchers should not assume they are interchangeable without verification in a specific primary source. In classical Latin usage, juramentum and jusjurandum both mean oath, but jusjurandum carried a somewhat more solemn and formulaic connotation in Roman legal texts. Whether that distinction had operational significance in a particular canon law court at a particular period is a question of historical context, not definition.
Why It Matters in Research
This term surfaces almost exclusively in research touching on medieval ecclesiastical procedure and early canon law. Researchers should be aware of two practical traps. First, the distinction between calumniæ juramentum and calumniæ jusjurandum is treated by Black's as essentially one of form only — the two terms refer to the same underlying oath, and historical sources use them interchangeably without consistent preference for one spelling or phrasing over the other. Searching only one variant will likely produce incomplete results. Second, the term belongs to a procedural vocabulary that largely dissolved with the decline of ecclesiastical court jurisdiction in England and the codification of canon law on the Continent; it does not translate into any surviving common law procedural requirement and has no modern statutory equivalent. Researchers working on the history of perjury, oath-taking, or the development of civil procedure will find this term useful as a waypoint connecting Roman civil procedure (where analogous oaths appeared) to later ecclesiastical practice and, distantly, to modern good-faith pleading obligations.
Historical Dictionary Support
Black's Law Dictionary (2nd ed.) defines the term tersely as an oath "similar to the calumniæ jusjurandum" found in "old canon law," and directs the reader by cross-reference to that companion entry for substantive content. This brevity reflects the term's status as a near-synonym rather than an independently developed doctrine. Black's does not elaborate on procedural details, timing within proceedings, or consequences for violation — gaps that are significant for the researcher. For fuller treatment of the underlying oath and its function, the calumniæ jusjurandum entry is the operative source. Historical canonist treatises and works on Roman-canon civil procedure provide the richer context that the dictionary entries alone cannot supply.