Section I. Ignorance

Ignorance is the absence of knowledge which the person who is ignorant should have. It is thus distinguished from nescience, which is merely the absence of knowledge, without the implication that the knowledge should be possessed.

Ignorance must also be carefully distinguished from error or mistake, which is a false judgement concerning something. Thus, if I simply do not know the person to whom I am speaking, I am in ignorance of his identity; if I mistake him for someone else, I am in error.

(a) With reference to the subject who is ignorant, ignorance is either invincible or vincible.

Invincible ignorance cannot be dispelled by the use of ordinary diligence. This may arise in my mind either because no thought of my want of knowledge occurs to me, and so the idea of making inquiries never enters into my head, or because I have failed to acquire knowledge on the point, though I made all reasonable efforts to do so. What efforts should be made in any given case depends on the character and circumstances of the person and the matter on which he is ignorant. If the matter is of great importance, if it affects the salvation of souls or the spiritual and temporal welfare of large numbers, great efforts must be made to dissipate ignorance; the efforts which would be sufficient in the case of one poorly instructed, or very much occupied with other weighty affairs, would not be It sufficient in other cases where these suppositions are not verified. In general, where knowledge is of obligation those efforts must be made to acquire it which ordinarily prudent and good men would exert in the circumstances.

Vincible ignorance is such as can be removed by the use of the requisite diligence. Various degrees are distinguished by divines according as some, or little, or no diligence is exercised to dispel it or means are used to foster it. If means are used to foster it, the ignorance is called affected; if little or no diligence is used to dispel it, it is called crass or supine; if some diligence is used, but not what is required in the case, it is called simply vincible ignorance.

(b) With reference to the object of ignorance, we must distinguish ignorance of law, fact, and penalty. 'There is ignorance of law, if the law’s existence is not known, as when a Catholic does not know that the Church forbids marriage within the third degree of kindred. There would be ignorance of fact, if it were not known that A. B. is related to C. D. within the third degree. Ignorance of the penalty is distinguished from ignorance of law when some special sanction is not known, though the law itself is known.

(c) With reference to the action of the subject, we distinguish antecedent, consequent, and concomitant ignorance. Antecedent ignorance is not voluntary, it is not willed by the subject; consequent ignorance is voluntary; concomitant is not expressly willed, but the action which is done with concomitant ignorance would ex hypothesi be done, even if the ignorance did not exist.

Invincible ignorance, as defined above, excuses from fault, so that, however bad an action done in invincible ignorance may be, it cannot be a formal sin. The reason is obvious; there is no knowledge in the agent of the malice of the action, and so the bad action is involuntary, and not imputable.

Vincible ignorance of the malice of the act, however, cannot excuse one who does wrong. He does not indeed will the evil in itself, but he wills its cause, and so it is voluntary in its cause and imputable. A person who sins in simply vincible ignorance, or even in crass ignorance, is indeed less blameworthy than one who sins with full knowledge of the malice of his act; the sin is only imperfectly voluntary, and less imputable than if perfectly voluntary. There is an apparent difference of opinion among theologians as to whether affected ignorance increases or lessens the malice of a wrong Prop. 2 damn. ab Alex. viii; 68 inter Baianas, can. 2202. action. With many modern authors it seems best to distinguish the motive with which in each case ignorance is fostered. If the state of ignorance is fostered through fear of being compelled by knowledge to abstain from the sinful act, such affected ignorance would seem to lessen the malice of the sin; the wrongdoer would not in this case venture to sin if he had full knowledge, and so he fosters his ignorance; his will is less malicious than if he sinned with full deliberation and consent. If, on the contrary, he merely fosters his ignorance to be able to plead it in excuse, and he is so bent on sinning that he would do the act in the same way even if he had full knowledge of its malice, then it does not seem to diminish the sin; it is rather a sign of an absolute determination to commit the sin.¹

We saw in a former chapter that the degree of malice which attaches to a sin committed in more or less culpable ignorance is measured rather by the sinfulness of the neglect to put away the ignorance, than by the sinfulness of the act in itself.

¹ Bucceroni, 1, n. 51, can. 2229.

Ignorance itself of what we are bound to know, as of the obligations of our state of life, of the truths of faith which are necessary to salvation, is sinful if consequent and vincible; antecedent and invincible ignorance is of course not sinful.

Ignorance does not render an act invalid which has all other requisites for its validity; and so baptism conferred by one who knows nothing about its effects will be valid, if the - matter and form are correctly applied with the intention of doing what the Church does. Substantial error or mistake about the person with whom marriage is contracted will invalidate the contract, while ignorance of who the person is will not, if there be the will to marry.