Moral Theology. Charles J. Callan
175. Hence in the following cases, even though there be serious matter, a sin is not mortal, on account of lack of full advertence. (a) When without one's will there is no full advertence to the act itself, as happens with those who are half-asleep, or who are under the influence of drugs, or who are mentally confined by anxiety or physical pain, etc. (see on Human Acts, 24 sqq.). (b) A sin is not mortal when there is no full advertence to the sinfulness or to the gravity of the act. Those who through no fault of their own are unaware that an act is sinful, or that it is a mortal sin (e.g., children, the half-witted, or the uninstructed), have no full advertence to the malice of the act; likewise, those who, without being responsible for their inadvertence, do not think at the moment of the sinfulness or seriousness of what they do (e.g., those who think out plans for revenge before they have taken second thought on its immorality).
176. Signs that indicate that there was no full advertence are: (a) if afterwards one can scarcely recall what happened; (b) if shortly afterwards one cannot be sure what was one's state of mind at the time.
177. Though full advertence is required for a mortal sin, it is not required that this advertence be the most perfect. (a) It is not necessary that the advertence be preceded by long deliberation, for advertence can be full even when the consideration is only momentary, (b) It is not necessary that advertence be continued during the commission of a sin, for what follows is foreseen if adverted to at the beginning. (c) It is not necessary that advertence to the malice of the sin be clear or exact. One who perceives that there is some special malice in robbing a church, even though he does not understand just what the malice is, has sufficient advertence to become guilty of sacrilege. Likewise, one who has doubts as to whether a certain sin is mortal, or who suspects that it is mortal, has sufficient advertence for grave guilt if he commits that sin. (d) It is not necessary that advertence to the malice of the sin be reflex (i.e., that one advert to the fact that one is conscious of the gravity of the sin); for to will the malice, it suffices that one be conscious of the malice. (e) It is not necessary that advertence to the malice of the sin be explicit (i.e., that one have in mind the precise nature of sin as an offense against God, which produces a stain on the soul and incurs the debt of punishment); for to will evil and its gravity, it suffices that one perceive the evil and its gravity, even though one does not analyze the meaning or seek out the ultimate reasons.
178. The third condition required that a sin be mortal is that full consent of the will be given it, for no one separates him self from God except through his own free choice. (a) Consent is not full, when there has not been full advertence, or when an act has been done under violent compulsion; (b) consent is full when there has been full advertence and no forceful compulsion (see above on Violence, 52).
179. Indications that consent was not full are: (a) if before the sin the person was of tender conscience and had habitually a horror of grave sin; (b) if at the time of the sin the person recoiled from the sinful suggestion—e.g., if he had a hatred for it as soon as it was fully perceived, or if he was saddened at the temptation, or if he kept from an external act that could have been easily performed; (c) if after the sin the person was conscientious, and yet had doubts as to whether consent was given.
180. Venial Sin.—A sin is venial, or more easily pardonable, when by it one turns inordinately towards some created good, not so, however, as to forsake God as one's Last End or to prefer self-will to the divine friendship.
181. The first condition required that a sin be called venial is that its matter be light, either in reality, or in the invincible belief of him who commits it. The criteria by which we may know what matter is light are authority and right reason (see above, 171).
182. The matter of a sin is light in two ways. (a) From the character of the act, the matter is light when the good which is injured is finite and of minor importance. Thus, truth about trivial things is of less importance among finite goods, and consequently a small lie about some unimportant matter, which helps and does not harm the neighbor, is light matter. (b) From the quantity of the matter, the matter is light when the good injured is of major importance but divisible. An example here is a theft that works only small harm (see above, 172).
183. The second condition for a venial sin is that there be some advertence to the malice of the act. (a) The advertence is not full when the matter is grave, and the act done without compulsion, for else the sin would not be venial but mortal. (b) The advertence may be full or partial when the matter is light.
184. The third condition for a venial sin is that there be some consent of the will to the malice of the act. (a) The consent is not full when the matter is grave, for else the sin would be mortal. (b) The consent may be either full or partial when the matter is light.
185. Imperfections.—The description of venial sin just given indicates that it is a voluntary transgression of the law of God in matters of lighter importance, and is thus distinguished from the various classes of moral imperfections. These latter imperfections are:
(a) natural imperfections, which are the falling short on the part of good acts of the higher degree of goodness they might have possessed. Since man is finite by nature, it is inevitable that he be limited in the good he does; and hence this kind of imperfection is not a transgression or a sin;
(b) personal imperfections which are voluntary but not transgressions, are acts or omissions whose motive is reasonable, but which are contrary to that which is of counsel. Example: to omit hearing a Mass that is not obligatory, when one is able to assist at it, but has a good reason for staying away;
(c) personal imperfections which are transgressions but not voluntary, are acts or omissions done without deliberation, but which are opposed to some law of less importance. Example: To pray with involuntary distractions.
186. Change in the Gravity of Moral Defects.-An imperfection becomes a sin: (a) if the motive for omitting what is of counsel only is sinful (e.g., to neglect a Mass that is not of obligation out of contempt); (b) if a slight indeliberate transgression has a cause that was voluntary (e.g., involuntary distractions caused by previous neglect).
187. Venial sins become mortal when that which in itself is a slight offense, becomes in the individual agent a grave offense by reason of some change in the object or of some grave malice in the purpose, circumstances, or the foreseen results (see above 97 sqq.).
188. A change in the object makes venial sin mortal: (a) when that which is light matter objectively is apprehended subjectively as grave matter (e.g., a person tells a small lie or commits a trifling theft, thinking these to be mortal sins); (b) when that which is light matter by itself becomes knowingly grave matter through the additions that are made to it (e.g., a thief steals small amounts frequently with the intention of having a great amount of ill-gotten money after a time).
189. It should be noted that, while the matter of venial sins may coalesce so as to form grave matter and constitute a mortal sin, as just explained, venial sins themselves do not, from mere multiplication, ever become mortal, since the difference between mortal and venial sin is not one of quantity, but of kind. Hence, when acts are slightly sinful but do not coalesce, they multiply venial sins, but do not form mortal sin. Example: Coming a few minutes late for Mass every Sunday.
190. The multiplication of venial sins, especially when they are held as of no importance, disposes for the commission of mortal sin: (a) directly, by forming a habit that calls for ever greater indulgence (e.g., petty thefts lead to dishonesty on a large scale); (b) indirectly, by familiarizing one with wrongdoing and chilling the love for virtue.
191. The wrong purpose of the agent makes an act that is only venially sinful (as far as the object is concerned) to become mortally sinful, when the purpose contains a grave malice in itself, for the act is then intended only as a means to what is seriously wrong (see above 80). Example: To tell a small lie in order to break up friendships and sow hatreds.
192. The circumstances of an act that is only venially sinful in itself also make the act mortally sinful, when there is grave malice in such circumstances. Cases of this kind are the following:
(a) The circumstance of the person committing the sin sometimes changes the malice from light to grave. Example: Unbecoming levity in one in authority may cause serious disrespect