Section — Prümmer, Manuale Theologiae Moralis
§ 3. On The Influence Of Ignorance And Inadvertence On Human Acts
Preliminary note. To ignorance also are to be referred forgetfulness and inadvertence, which, if they are perfect, are equivalent to invincible ignorance; but if they are imperfect, they exercise the same influence upon the morality of the act as vincible ignorance. Therefore the following two principles are valid in the same way concerning ignorance and concerning inadvertence and concerning forgetfulness.
45. Principle 1. Invincible (antecedent) ignorance takes away the voluntary, and therefore also the imputability of any act which has been produced from it.18 Authors are accustomed to say briefly: Antecedent ignorance excuses from sin.
The reason is that he who acts from invincible ignorance inculpably lacks cognition of the morality of the act. But nothing is willed unless it is foreknown. Wherefore the Jansenistic proposition (2) was condemned by Alexander VIII: "Although invincible ignorance of natural law be given, this, in the state of fallen nature, does not excuse one acting from it from formal sin."19 St. Augustine expressly says: "It is not imputed to you as fault if you are unwillingly ignorant."20
Resolves: a) He does not sin who eats meat on Friday while invincibly thinking it is Thursday.
b) Infants before the use of reason do not sin when perpetrating something against natural or divine law.
c) A youth invincibly ignorant that some book is on the Index of prohibited books sins if he reads it and afterward, when he perceives the prohibition, rejoices over the reading, saying that he would have read the book even if he had known the prohibition. He sins not indeed by the reading itself, since it was done with invincible ignorance, but by the joy afterward had.
18 Cf. S. theol. I-II, q. 76, a. 3 and q. 6, a. 8.
19 Denz. 1292; cf. also ibid. 1068.
20 De lib. arb. 3, c. 19 (Migne, Patr. lat. 32, 1297).
46. Principle 2. Vincible ignorance a) does not take away the voluntary; b) nevertheless diminishes it, unless c) it is affected.
The reason for the first is that, notwithstanding vincible ignorance, the acts could and should have been foreseen and known. For since vincible ignorance itself is voluntary, the effects also following from it are voluntary. Peter Abelard seems to have taught the contrary, and therefore his proposition was condemned: "that whatever is done through ignorance is not to be ascribed to fault."21
The reason for the second is that here and now perfect cognition is truly lacking, which, if it were present, the action would not occur. But when perfect cognition is lacking, the perfect voluntary also is lacking, or the voluntary is diminished. Nevertheless vincible ignorance (at least if it is crass) is not accustomed to diminish the voluntary to the point that an act otherwise mortally evil becomes a venial sin.
The reason for the third is that affected ignorance is accustomed to arise either from an evil will causing it for sinning more freely,22 or from contempt of the law.
Resolves: a) A confessor, physician, advocate, etc., who from very imperfect knowledge necessary to their office err in particular cases, sin, because they could and strictly should have procured sufficient knowledge for themselves. For their ignorance is vincible and culpable.
b) The faithful who neglect to learn the truths of faith and the precepts of morals sin if from ignorance they err concerning faith or transgress moral precepts. Nevertheless their sin is less than if they knowingly transgressed the same precepts.
c) The faithful are bound to acquire sufficient cognition of the truths of faith and morals, lest from ignorance they err in matters which pertain to the salvation of the soul.
The two principles enunciated can also be briefly expressed thus:
1. Antecedent ignorance causes the simply involuntary. Consequent ignorance causes the simply voluntary and the involuntary in a certain respect.
2. Concomitant ignorance indeed causes the non-voluntary, but not the involuntary23 (concerning the distinction between the involuntary and the non-voluntary, see below n. 56).
3. Antecedent ignorance excuses; consequent ignorance accuses; concomitant ignorance neither excuses nor accuses.
21 Denz. 377.
22 Cf. S. theol. I-II, q. 76, a. 4: "Ignorance (affected) seems to increase the voluntary and sin: for from the intensity of the will toward sinning it comes about that someone wishes to undergo the harm of ignorance because of liberty in sinning." Cf. also De malo q. 3, a. 8.
23 Cf. S. theol. I-II, q. 6, a. 8.
47. Scholion 1. On the inadvertence of the customary sinner. It can happen that a man is so bound up in evil habits that he elicits evil acts without any actual advertence to the malice, and those habits become as a second nature. This indeed can occur, for example, from the habit of blaspheming, fornicating, lying. In these cases a distinction is needed: Either the evil habit has been efficaciously retracted through sincere contrition, and then the acts produced without advertence are involuntary and therefore inculpable; or the evil habit has not been retracted, and then the individual acts do not lack fault, because they should have been foreseen and guarded against; indeed such acts are graver sins, since they proceed from a deep-rooted habit freely admitted.24 Nevertheless in the confessional customary sinners of this kind are not to be too much tormented so that they state the number of individual acts. For investigation of the exact number is impossible, and rude penitents are accustomed to answer the questioning confessor whatever comes into their mouth, as St. Alphonsus says. Therefore it suffices if the confessor asks through what length of time the penitent has lived in such a habit, and about how many acts he committed each day.
Scholion 2. On ignorance of ecclesiastical laws and penalties. Although ignorance of invalidating or incapacitating laws (for example, impediments of marriage, irregularities) does not excuse from the same, unless something else is expressly said (c. 16, § 1), nevertheless "The violation of an unknown law is in no way imputed, if the ignorance was inculpable; otherwise imputability is diminished more or less according to the culpability of the ignorance itself" (c. 2202, § 1). But as often as because of ignorance (or some other cause) the transgression of the law was not gravely culpable, no ecclesiastical penalty is incurred (c. 2218, § 2). Grave fault, however, is not always required if there is question of imposing penances or penal remedies.
As to ignorance of ecclesiastical penalties, these things have been established: a) Ignorance of only the penalty does not take away the imputability of the delict, but diminishes it somewhat (c. 2202, § 2); b) Affected ignorance, whether of the law or only of the penalty, excuses from no penalty; but crass and supine ignorance excuses from penalties alone, if the law has the words: shall have presumed, shall have dared, knowingly, deliberately, rashly, with purpose aforethought shall have acted, or other similar words; c) Other ignorance indeed excuses from medicinal penalties, but not from vindicative penalties (c. 2229).
24 S. theol. I-II, q. 78, a. 2; cf. also below n. 90.