Article — Wouters, Manual of Moral Theology
Article I. Irregularities and Impediments in General
I. Notion. An irregularity is a canonical impediment of itself perpetual, which prohibits the reception and exercise of Orders (cf. canons 968 and 983). It is called an impediment:
Canonical, that is, established by ecclesiastical law.
Of itself perpetual, that is, one which is not removed except by dispensation; and by this reason it differs from a simple impediment.
Of the reception and exercise of Orders. But by the name Orders here first tonsure also comes (canon 950). The reception and exercise of Orders are prohibited, but not the exercise or acts of jurisdiction alone, such as to dispense, to absolve from a censure, to give the faculty of absolving from sins (St. Alphonsus, VII, 342). Finally, the functions of the Acolytate are no longer prohibited, since today they are permitted even to laymen.
It prohibits; but it does not render the reception and exercise of Orders invalid. The prohibition, however, is grave, as is drawn both from the nature of the thing and from the grave penalties to be imposed on a transgressor (canon 2374).
A simple impediment is a canonical impediment of itself temporary, which prohibits the reception and exercise of Orders (cf. canons 968 and 987). It is called of itself temporary, that is, one which can cease without dispensation or by the fact itself.
Note. Irregularities and impediments have been established so that provision may be made for the reverence due to Orders, but not by way of penalty, except perhaps secondarily if it is a question of an irregularity from delict (St. Alphonsus, Homo Apostolicus, tr. 17, n. 73).
II. The origin of irregularities is ecclesiastical law (canon 983); the same holds for simple impediments. Moreover, the cited canon sufficiently signifies that irregularity is introduced by written law alone, not by custom.
III. Interpretation; concerning it observe:
Laws which constitute an irregularity or impediment, as restricting rights, are subject to strict interpretation (cf. canon 19).
Only the baptized are bound by the said laws; this, however, does not prevent a fact which had place before baptism from being able to induce irregularity after baptism, as if someone had been insane before baptism. The impubes are not exempt from the law.
In doubt of law - that is, in doubt whether the law has been passed or extends itself to some case - the law does not urge. In doubt of fact - that is, in doubt whether the fact which carries an irregularity or impediment with it took place, or was such as is supposed by the law - the law likewise does not urge; for it is a question of doubt of a fact founding a prohibiting law (St. Alphonsus, VII, 422, 432; t. I, n. 228);1 moreover, in the latter doubt the Bishop can dispense for precaution (cf. canon 15).
Ignorance of irregularities, whether from delict or from defect, and of impediments, does not excuse from them (canon 988).
1 Sacred Congregation of the Council, June 27, 1857 (A.S.S. I, p. 350).
IV. Multiplication. Irregularities and impediments are multiplied from their different causes, but not from the repetition of the same cause, unless it is a question of irregularity from voluntary homicide (canon 989). It is said:
From their different causes; as if someone is illegitimate and perpetrates homicide. Yet note that formally different causes suffice, and that several formally different causes can be contained in one and the same physical act; as if someone by the same blow were to kill another and attempt to take his own life.
Unless it is a question of irregularity from voluntary homicide. Procurement of abortion does not come under the name of homicide; for canon 985, 4° distinguishes this from homicide, and the law is of strict interpretation. But craniotomy and similar cruel killings of an infant are comprehended under that name.