Definition
In civil law pleading, the explicatio is the fourth pleading in the formal sequence of a civil law action. It is the pleading by which the original plaintiff responds to the defendant's supplicatio (the third pleading), and functions as the counterpart to the surrejoinder in common law procedure. The explicatio is technically characterized as an allegatio infirmans supplicationem — a statement that undermines or defeats the supplicatio.
Common Confusion
Explicatio is one of four parallel pleadings in the civil law sequence that researchers sometimes conflate or encounter out of order. The sequence runs: libellus (or positiones) by the plaintiff, responsio by the defendant, supplicatio by the defendant in reply to plaintiff's further allegation, and explicatio by the plaintiff in answer to the supplicatio. The nearest common law analogs, in matching order, are the declaration, plea, rejoinder, and surrejoinder. Researchers encountering any of these civil law pleading terms should resist direct substitution with the common law equivalents — the structural logic of civil law pleading is distinct enough that equivalences are approximate, not exact.
Why It Matters in Research
Explicatio is a term of narrow historical and procedural significance with no living application in modern American or English law. It surfaces almost exclusively in sources dealing with Roman civil law, canon law procedure, or early civilian jurisdictions in Europe and Scotland. Researchers working in the Law Mind corpus are most likely to encounter explicatio in treatises on Roman law, comparative procedural works, or glossaries appended to early modern legal texts.
The principal research trap is treating civil law pleading terminology as a rigid one-to-one map onto common law stages. The surrejoinder analogy given by Black's is a serviceable orientation, but civil law pleading structure varied across jurisdictions and periods. In canon law courts and mixed civilian jurisdictions, the number and labeling of pleading stages differed from the classical Roman sequence, so explicatio may appear with slightly variant meanings or positional numbering depending on the source.
Researchers should also note that primary authority for this term runs through Calvin's Lexicon Juridicum (Calvinus, Johannes, Lexicon Iuridicum Iuris Caesarei), a foundational glossary of civil and canon law terms that both Black's and Burrill cite. Any deeper investigation of explicatio's procedural meaning should consult that source directly rather than relying solely on the secondary digest offered by the English-language law dictionaries.
Historical Dictionary Support
All three source dictionaries are in close agreement. Black's (both editions) and Burrill define explicatio identically as the fourth civil law pleading equivalent to the surrejoinder, and all three trace the term to Calvinus. Burrill adds value by supplying the Latin technical characterization — allegatio infirmans supplicationem — which Black's omits, and by cross-referencing Spiegelius alongside Calvinus. That Latin phrase is useful because it captures the functional purpose of the explicatio: it is not merely a response in sequence but specifically a pleading designed to undermine the supplicatio that preceded it.
None of the source dictionaries elaborate on procedural context, jurisdictional variation within civilian systems, or the relationship of explicatio to canon law practice. For a term of this depth, the dictionaries function as pointers to primary sources rather than complete analyses.