IPSO FACTO e IPSO IURE. - These two formulas are equivalent in meaning, and their use is found especially in penal matters: precisely to designate, in an equivalent way, penalties latae sententiae. The synonymity of the two expressions is authoritatively established by the legislator of the CIC (can. 2217,2).
By them is meant to express the perfect coincidence that exists between the transgression of the law and the penalty incurred automatically, without the concurrence of human wills. Once the offense is committed, complete in its kind, the penalty necessarily follows, as avenger of the social disturbance. In the sources of canon law these expressions are frequently found with identical meaning. Ipso facto is found in c. 2, de rebus ecclesiae non alienandis, III, 9, in VI, together with the expression eo ipso; c. 1, de homicidio, V, 4, in VI; c. 1, de usuris, V, 5, in VI; c. 3, de poenis, V, 8, in Clem. Pius VI also uses it in his const. Auctorem fidei, 28 Aug. 1794, prop. 47, against the Jansenists (cf. Denz-U, 1547). Ipso iure is found in c. 25, X, de sententia excommunicationis, V, 39; c. 37, de electione et electi potestate, I, 6 in VI; c. 5, de poenis, V, 9, in VI together with the expression eo ipso, which is also found in isolation in c. 16, de electione et electi potestate, I, 6 in VI; c. 11, de sententia excommunicationis, suspensionis et interdicti, V, 11 in VI. The CIC retains this wording only in cann. 2346, 2365, 2381 n. 1. The other expressions used in the canonical sources are ipso actu: c. 24, X, de appellationibus, recusationibus et relationibus, II, 28, and ipso suo genere in c. 26, X, II, 28. In the CIC the expression ipso iure is found several times; ipso facto is more used.
Worthy of particular note, for the subject under discussion, is the deprivation of a benefice, which can occur ipso iure et per sententiam declaratoriam of the judge. In this case the penalty is retroactive to the day on which the crime was committed, and from that time the guilty party ceases to be the holder of the benefice.
These expressions are used by the CIC also to indicate the law that immediately invalidates an act or disqualifies a person; cf. cann.: 162,63; 165; 166; 181,62; 150; 185; 188; 192; 646; 1068; 1307,63; 1684; 1679; 2167.