William Feilden Craies, 1911 Encyclopædia Britannica, Volume 28… (1911)
“ The use of the oath instead of the real or feigned combat—real in English law, feigned in Roman law—no doubt represents an advance in legal development. The technical term sacramentum is the bond of union between the two stages of law. In the wager of law the defendant, with eleven compurgators, appeared in court, and the defendant swore that he did not owe the debt, or (in detinue) that he did not detain the plaintiff's chattel ”
