Summa summae S. Thomae, Tomus II

I suppose, from the tract. on Human Acts, dissert. I, the division of ignorance into antecedent, concomitant and consequent. Re-read.

I say 1°: Ignorance can be a cause of sin ¹, not per se, because since it is privation and not a being, it cannot of itself influence an act; but per accidens, as removing what prohibits, inasmuch as it removes knowledge which, if present, sin would not be committed.

I say 2°: Concomitant ignorance is not a cause of sin ², because it does not remove knowledge which, if present, would impede sin, but with it present sin is committed equally. Antecedent and consequent ignorance are causes of sin, because they take away knowledge by which, if present, sin would be prohibited: yet with this difference, that antecedent ignorance is only a cause of the act of sin, or of sin taken not formally but materially, because the act following from it, as regards the circumstance of sin, is involuntary, since that circumstance is invincibly ignored; but consequent ignorance is a cause of sin formally, because the act following from it, even as regards the character of formal sin, is voluntary, since this character is voluntarily and vincibly ignored. Concerning antecedent or invincible ignorance of divine and natural law, whether it exists and whether it excuses from sin, we shall speak more fully in what follows.

I say 3°: Invincible ignorance is not sin; vincible ignorance of things one is bound to know is formally in itself sin, not however on account of its own self, but on account of negligence in learning ³. But all are bound commonly to know: 1° the things that are of faith, 2º the universal precepts of law, 3° each one, those things which pertain to his state and office.

The Reason of the first part: because invincible ignorance, since it is not in our power to overcome it — for it is called invincible because it cannot morally be overcome — is not voluntary. It will appear more clearly from what must be said below.

The Reason of the second part is: because voluntary omission of a due act is formally in itself sin. Yet vincible ignorance of things one is bound to know is voluntary omission, at least indirectly, of a due act, namely due cognition, in negligence of learning. Ergo.

[You will ask 1° what things are causes of vincible ignorance.

I answer. Four are counted, namely: negligence, passion, wicked habit, thoughtlessness.

1° Negligence. « When anyone, says St. Thomas, 1a 2ae, q. 76, a. 3, c, neglects to learn, on account of labor or other occupations, that whereby he would be withheld from sin, such negligence makes ignorance itself voluntary, and sinful, provided it be of things one is bound and able to know. » But that ignorance be sin, there is required 1° that it be of things one is bound to know, e.g., things that are of faith and the universal precepts of law, or those which concern one's own state or office; 2° that negligence in learning be voluntary and culpable, that is, that man advert to the obligation imposed upon him and to the means proposed to him for acquiring competent knowledge, and refuse to employ them; for, as the Angelic Doctor says, q. 3 de Malo, a. 7, c, negligence from which culpable ignorance is born is nothing else than « not applying the mind to knowing what one ought to know. »

2° Passion. For ignorance becomes voluntary through passion when someone deliberately wills to follow it, foreseeing at least confusedly and in general the evil effects naturally about to arise from such passion, though he perceive them not in particular; for then he wills them at least in their cause. Whence St. Thomas says, q. 3 de Malo, a. 10, c: « Posited that reason be bound by passion, it is necessary that perverse choice follow. But it is in the power of the will to repel this bond of reason. For reason is bound from this, that the intention of the soul is applied vehemently to the act of sensitive appetite, whence it turns away from considering in particular what it knows habitually in universal. To apply intention to something or not to apply it exists in the power of the will. Whence it is in the power of the will that it exclude that bond of reason. The act therefore committed which proceeds from such a bond is voluntary: whence it is not excused from guilt, even mortal. But if the binding of reason through passion proceeded so far that it were not in the power of the will to remove a bond of this kind, suppose that through some passion of soul one should fall into insanity, whatsoever he might commit would not be imputed to him as guilt, as neither to another madman, except perhaps as regards the principle of such passion, which was voluntary; for the will could have impeded from the beginning that passion proceed so far. »

3° Wicked habit. Ignorance becomes voluntary by reason of a wicked habit, when namely someone does not care efficaciously to amend a wicked habit. For those acts are sins formally which are sufficiently voluntary in themselves or in their cause. Yet acts which proceed from a wicked habit are sufficiently voluntary in themselves or in their cause, namely in the bad custom which was voluntarily contracted. They are also sufficiently deliberate; for, as St. Liguori says, lib. II, de Peccatis, n. 4, « sinners of this kind ill habituated, although they have cognition less prompt than others, nevertheless always have some actual cognition of their crimes sufficient for rendering acts deliberate and mortal. For since they make little account of sin, there is not made in their souls that sensible and memorable impression which is made in another having conscience less depraved: and hence it happens that in their memory there remains no vestige of that actual cognition which they had sufficiently before concerning the sin, or a vestige so light, that being questioned they easily answer that they did not advert. » Ergo.

4° Thoughtlessness. To prudence pertains to regulate all actions of man; and since nothing right or rightly done can be done without her guidance, and thoughtlessness is opposed to her, whatever acts are done together with ignorance arisen from thoughtlessness become sins, because such ignorance can easily be overcome. Thus St. Thomas proves, 2a 2ae, q. 53, a. 4, c, that thoughtlessness is a special sin contained under imprudence: « Consideration chiefly pertains to judgment. Whence also defect of right judgment pertains to the vice of thoughtlessness, insofar namely as someone fails in judging rightly from this, that he will not consider the things he can consider. »

You will ask 2° whether culpable ignorance of things one is bound to know is a special sin distinct from the sins of which it is the cause.

I answer. 1° Ignorance of things which man is bound to know not on account of themselves but on account of the work here and now to be done or avoided, is not a special sin distinct from the sin which follows from it, because by no other title is one bound to know those things than by reason of the work here and now to be done or omitted; and thus it takes its whole malice from that work, no otherwise than an act good or indifferent from elsewhere which is the cause of culpable omission takes its whole malice from the omission, and constitutes one sin only with it. Hence he who approaches one not his own, vincibly ignoring that she is married ⁴, commits one sin only of adultery; likewise he who does not fast on the vigil of St. Matthew, vincibly ignoring it to be the vigil ⁵ : and it suffices to say in confession: « I committed adultery, I did not fast on the vigil of St. Matthew, » without his accusing his vincibile ignorance.

2° But ignorance of things which man is bound to know on account of themselves is a special sin distinct from the sin of which it is the cause, opposed to studiousness. For then ignorance does not take its malice from the effect or consequent sin, but has it according to itself, inasmuch as it is against the precept of knowing these things on account of themselves and not on account of a work here and now to be done or omitted. Hence he who from vincible ignorance of the Incarnation blasphemed against Christ would sin with twofold sin: of ignorance against infused studiousness, and of blasphemy against religion; likewise he who from ignorance that adultery is sin would commit it; also a confessor, judge, physician who vincibly ignores the things of his office or state, by this very fact sins with a special sin of ignorance, and if thence he act badly, or there be proximate danger of acting badly, he commits another distinct sin; for he is not bound to know these precisely by reason of a work here and now to be done or omitted, as in the first answer, where such obligation is transient with the work, but by reason of state, and therefore it is permanent.

You will ask 3° what ignorance is reckoned invincible.

I answer. that ignorance to be invincible which cannot be overcome with moral diligence employed. I say moral, not supreme, but such as prudent and God-fearing men are wont to employ in similar business.