Compurgation is a judicial proof of innocence commonly permitted in medieval ecclesiastical courts. Owing something to Germanic law, but deriving from the apostolic statement that "an oath for confirmation is the end of all controversy" (Heb 6.16), it allowed a defendant to clear himself (purgare ) of an accusation by calling on specified "oath-helpers" (coniuratores, compurgatores, Eidhelfer ) to substantiate his oath to his own innocence (see Corpus iuris canonici, ed. E. Friedberg (Leipzig 1879–81; repr. Graz 1955) C.2 q.5 for the chief patristic and papal texts). These "helpers" as a rule were not to exceed the "canonical number" of seven and had to be from the social stratum of the accused; their oath was not to testify to the truth as such, in the manner of witnesses or jurors, but simply to the truth of the oath sworn by the accused. In essence compurgation (purgatio canonica ) was the ecclesiastical counterpart of ordeals (purgatio vulgaris ), for in either case the judgment was referred to God; on occasion an accused was presented with a choice of one or the other. Likewise, compurgation was just as hazardous a method of discovering the truth, and by the 14th century it was almost wholly discredited. A form survives in modern civil law in the institution of character witnesses.
Bibliography: r. ruth, Zeugen und Eideshelfer in den deutschen Rechtsquellen des Mittelalters (Breslau 1922). f. pollock and f. w. maitland, A History of English Law Before the Time of Edward I (2d ed. Cambridge, Eng. 1898; repr. 1952) 1:443–444; 2:633–637. n. del re, a. mercati and a. pelzer, Dizionario ecclesiastico, 3 v. (Turin 1954–58) 3:389. j. lederer, Lexikon für Theologie und Kirche, ed. j. hofer and k. rahner 10 v. (2d, new ed. Freiburg 1957–65) 3:731.
[l. e. boyle]
J. A. Cannon