INTRODUCTIO CAUSAE. — With the introduction of the cause (also called *introduttio litis*), the path is opened to the constitution of the process, and the dispute becomes pending.
The process is indeed said to be introduced with the judicial petition of the plaintiff presented to the judge and communicated to the opposing party through the citation for the joinder of issue. Two conditions must therefore be fulfilled for the process to be said to be constituted: a) the request for the exercise of judicial authority, by which the right that one party claims against the other is to be enforced, and this is done through the judicial petition contained in the libellus (q.v.); b) the citation (q.v.) of the other party, to whom the plaintiff’s claim is communicated, so that the party may either yield, thus terminating the process, or defend itself against the claim. All this precedes the joinder of issue, through which the object of the controversy is more precisely determined, upon which the judge must pronounce.
The first two acts, the judicial petition and the citation, constitute the introduction of the cause, which the CIC treats in tit. VI, caps. 1–2, cann. 1706–1725.
For the meaning to be given to the term *introduttio causae* (can. 2038) in processes of beatification and canonization: q.V. BEATIFICAZIONE, I, *La b. nella liturgia e nel diritto*.