Whether pertinacity is required for someone to be a heretic, and if so, of what kind.
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So the common and most true judgement of theologians teaches that there is no need for this warning, or for length of time or delay, for someone to become a heretic and incur the penalties of heretics, but that it is sufficient for him to embrace error with full deliberation and express what he sees to be at odds with the understanding and definition of the Church. This is taught by Suarez [reference given], Cajetan, Vasquez, Valentia and countless others quoted and followed by Sanchez [reference given] and Diana [reference given] who, on the authority of others whom he quotes, well remarks against Alciatus and others that not even in the external forum is a warning and preceding correction always required for someone to be punished as pertinacious and that this is not observed in the practice of the Holy Office. For if it be certain by some other means - for example, if the doctrine in question be well known, or if it be obvious from the kind of person and other circuмstances involved - that the accused person could not have been ignorant of the opposition of his doctrine to that of the Church, he will automatically be judged a heretic. The reason he is asked in his trial whether he knew that his view was contrary to the doctrine of the Church, is that, if he admits that he did, he will already be thought sufficiently to have confessed heresy and pertinacity.

The reason for this is clear: the external warning can serve only to ensure that the erring party become aware of the opposition between his error and the doctrine of the Church. So if he knows the whole subject much better himself from books and conciliar definitions than he could from the words of anyone admonishing him, there is no reason for a warning to be necessary for him to be pertinacious against the Church. Neither is any length of time necessary for this, because the authority and mind of the Church can be known very quickly and no less quickly deliberately rejected, as takes place in the case of other sins.

Good evidence of this is adduced from the contrary act - the act of faith - which a man can elicit very quickly, reverently submitting himself to the Church and embracing her teaching. Seeing that the nature of contraries is the same, no more time is required for a man pertinaciously to withdraw from the Church than constantly and most firmly to adhere to her. Nor is this contradicted by the words of St. Paul which are alleged in opposition; on the contrary, as Suarez remarks, they imply that the individual in question is already a heretic before the warning, because he says: "A man that is a heretic, after the first and second warning avoid." The warning is required, therefore, to justify our separating ourselves from him - his incorrigibility being established by the warning - lest we endanger ourselves and waste our efforts with no hope of recovering him. We can add that this text is addressed to Titus, who, as he was a bishop, had to seek after wandering sheep like a shepherd in order to bring them back to the fold of the Church. But to private individuals it will often be more salutary to avoid a heretic straight away if they know that he sins not through ignorance but through malice; for they must look to their own good and beware lest, wishing to heal him, they expose themselves to danger of infection. Finally, in the same sense, St. Augustine, at the place quoted above, teaches that the heresy of one who has rejected correction is sufficiently certain, because before correction he could have excused himself on the pretext of ignorance, sometimes dishonestly and sometimes truly.

Hence, in the third place, doubt is often raised as to whether it is sufficient for the required pertinacity if someone who has been warned and rebuked by the bishop or by inquisitors does not acquiesce in their judgement, but persists in his error. The first opinion declares that it is sufficient; and this is held by Cardinalis, Bartolus, Penna, Farinacius and others quoted by Suarez [reference given], to whom can be added Castrus Palao [reference given]. The second opinion denies that it is sufficient, however, because the bishop and inquisitors are not infallibly correct in proposing a truth, and they do not have the assistance of the Holy Ghost to make what they say a trustworthy rule of belief; on the contrary, they can go astray and lead others astray in matters of faith, for which reason an individual might be prepared to believe the Church, but unwilling to believe the bishop and inquisitors, who are not the Church. This is the view of Cano, Vasquez, Sanchez and others [references given], Valentia, Torres, Salas and others quoted by Diana at the reference given above. Finally, the third opinion makes a distinction and says that the first opinion is true in the external forum, but the second in the internal forum - this is the view, more or less, of Suarez [reference given], Lorca and others cited and followed by Diana, loc. cit.

But I find the distinction between internal and external fora in this respect a difficult one. Because either the proposition made by the bishop and by the inquisitors is such that it truly imposes the obligation of believing - and in this case one who does not believe will be pertinacious in the internal forum also, because he is resisting a doctrine of faith proposed to him sufficiently to oblige him to believe it - or else the proposition is not such as to create an obligation in conscience to believe, and in this case not only will the individual who does not believe not be pertinacious in the internal forum, but likewise he cannot be judged pertinacious in the external forum either. This is because the external forum does not make a judgement contrary to the internal forum except on the basis of a presumption founded in some external circuмstance sufficient to justify the presumption: hence, if the proposal [of the doctrine in question] made by the bishop or inquisitors in those circuмstances is not of itself sufficient to make belief obligatory, one who withholds belief despite such proposal must not be judged pertinacious even in the external forum.

Suarez, however, rightly points out (loc. cit.) that generally the instruction and proposal made by a bishop or inquisitors is sufficient to oblige belief so that one who resists it is pertinacious; because generally it is not made without great consideration and learning, and is made only on those matters already defined and commonly received in the Church. The a priori reason for this is that, just as we are bound to believe Divine revelation, the certainty of which is not [in itself] evident to us, when the circuмstances in which it is proposed to us are such as to make it evidently credible and impossible for us prudently to deny it, doubt it or fear that it is not so; so, likewise, it is not necessary that the proposal of the Church by which God speaks to us indirectly should be [in itself] evidently certain to us, if the circuмstances in which this doctrine of the Church is proposed to us are such as to make it evidently credible to us that what is being proposed to us is a doctrine of the Church and that we cannot prudently doubt this or fear that it might not be so.

Now the circuмstances which generally obtain are of this kind - generally, neither the pope nor the Church assembled in a council directly proposes these teachings to the faithful, but rather they do so indirectly through their ministers. But at the same time it is also true that sometimes the persons who propose the doctrine, or the circuмstances in which the doctrine is proposed, are not such as to oblige everyone firmly to believe with Divine faith. On this subject I consider that caution is called for in differentiating between the learned and the unlearned referred to by Castro Palao (loc. cit. n.6), following Sanchez and others, when he says that a learned man is more easily presumed pertinacious than an unlearned and rustic man if he dissents from mysteries proposed to him, because a rustic man can more easily be unaware of the rules of faith and the obligation of believing.

This rule must be understood with a distinction. For if it applies to the judgement of an accused person in respect of some propositions which he has uttered and taught, a learned man is more easily presumed to have said them with a heretical disposition, because it is presumed that he knew them to be opposed to the teaching of the Church and of councils, which a rustic man could have been unaware of, as is remarked, with Albertinus and many others, by Diana (loc. cit., in the chapter beginning "Notandum est tamen"). But if what is at issue is the pertinacity evinced when the accused person does not submit himself to the judgement of the bishop or inquisitors proposing some doctrine to him as one that must be believed and professed, I think that a rustic man is more easily judged pertinacious in respect of heresy if he resists than a learned theologian. For we have seen above, in Disputation 5, Section 2, that lesser motives of credibility suffice for a rustic man to oblige his belief than for a learned man who better penetrates the grounds for doubt; for which reason sometimes a rustic person who does not acquiesce in the judgement of the bishop or inquisitors cannot be excused from the pertinacity of heresy although a learned theologian could be excused from that degree of pertinacity required for heresy if he brought forward some probable reason for his not being obliged, which the rustic could not bring forward as he would not know one. This is admitted also by Lorca in the present disputation XLI, n.21. I do not mean by this, however, that the judges of faith and inquisitors cannot in that case decide to condemn even the theologian as pertinacious; but I say that they cannot do so as briefly and easily as they could a rustic to whom it is enough to propose the doctrine of the Church. By contrast, should a learned theologian deny that the doctrine is the doctrine of the Church, and adduce prima facie convincing evidence [fundamenta apparentia] that his critics are mistaken and have condemned his assertions without justification, he must be satisfactorily answered and disputed with, and the grounds of the censure must be explained to him, so that he either is convinced or, in the judgement of wise men, ought to be convinced that the censure was deservedly passed. And if he does not acquiesce after this, he can reasonably be declared pertinacious, for a new declaration of the Pontiff is not needed in every individual case in order that those who err in the faith may be corrected and punished.

The fourth disagreement concerns whether this pertinacity implies the wish directly to resist the authority of the Church, or whether it be sufficient to wish this only indirectly. Suarez (Sect.III n.22) says that one must wish to do so directly, but Vasquez [reference given] and Sanchez [reference given] say that it is enough to wish it indirectly. In fact, however, both sides are in agreement although they express themselves differently. They mean that there is no need for the contradiction - and the resistance against the authority of the Church - to be itself the formally intended end, as would be the case if someone denies certain truths specifically for the sake of contradicting the Church; a disposition which is what Vasquez and Sanchez refer to as directly wishing the resistance itself. They insist instead that it is enough to know the contradiction between an idea and the mind of the Church and nonetheless to hold it, whatever end this may be done for - whether financial gain, renown or some other motive - which they term an indirect wish.

And as a matter of fact this is most definitely true. Just as in other sins too it is sufficient to sin against obedience, justice, religion and other virtues even though the end formally willed is not the injustice, the disobedience or the irreligion, etc., so pertinacious sin is also committed against the authority of the Church by denying that which we know the Church to teach, even if we do not intend formally to contradict the Church.

With regard to the semantic disagreement, we prefer that, whenever opposition to the doctrine of the Church is recognised, the resistance be termed directly willed (following the usage of Fr. Suarez), despite its not being formally intended. The reason for this is that a person who wishes something necessarily connected with a given effect, even though he does not intend the effect itself, is said to will it directly, because by willing the cause he implicitly wills the effect which is virtually included in that cause. Thus, one who gives a pregnant woman a potion to abort an animated foetus is called a voluntary homicide because, even if he does not intend the slaughter of the foetus, and indeed would prefer that after being aborted it should live, he does nevertheless will the cause necessarily connected - per se - with the death of the child, and he is therefore said directly to will that death because without direct will of slaughter the irregularity of voluntary homicide is not contracted, as Suarez remarks together with all doctors [reference given].

So the will to believe what one knows to be contrary to the doctrine of the Church - an assent which cannot exist without resistance to the Church - is truly a direct will to resist the Church. Even so, this will can exist in two distinct ways:

(i) One can intend to resist the Church in such a way that the resistance itself and opposition to the Church is, conceived as such, the intrinsic object of the heretical will. This applies to anyone who foresees the contradiction he is about to place himself in with the mind of the Church and still wishes to contradict and oppose the Church - even if he does not intend this opposition formally and for its own sake, but only materially and for some other end, for instance to retain his own opinion or for the sake of renown or financial gain - as long as the act of will itself is intrinsically ordered to that resistance and contradiction as the object willed, albeit not formally but materially.

(ii) One can choose to resist the Church in such a way that the resistance is only an extrinsic object of the act of will. This is the case when one realises that the assent one is contemplating is in contradiction and opposition to the doctrine of the Church, yet one still wills that assent, without however saying, "I will to dissent from the Church," instead declaring simply: "I will to deny the real presence of Christ in the Eucharist." And this will, given the recognition of the statement's repugnance to the doctrine of the Church, wills the opposition to the Church and wills it directly, because it wills directly an assent which is opposed to the Church, and hence wills something which is, in reality, a formal opposition to the mind of the Church, although the act of will is not intrinsically determined to that object under this formality and in so far as it is an act of opposition to the Church.

Both manifestations of the will to resist the Church suffice to constitute that pertinacity which makes one a heretic, because in both cases the will opts for a dissent by which it is recognised that the intellect will be in disagreement with the doctrine of the Church. Just as one who decides to eat flesh meat on a day of fasting, while aware that this is forbidden by the Church, wills to violate the precept of the Church, even if the act of will itself is not always intrinsically directed against the prohibition as its formal or material object, but only determinatively ["specificative"] to the object which is forbidden, namely the enjoyable eating of flesh meat which is nevertheless recognised and proposed by the intellect as forbidden; for this is the factor which entitles us to say that a forbidden object and the violation of an ecclesiastical precept are directly willed.

In the fifth place, there is disagreement as to whether, for heretical pertinacity, one must recognise the opposition between his opinion and the doctrine of the Church which has infallible authority in proposing, and also recognise that she does in fact propose the contrary of what he holds. First of all, it is certain that there is no need [in order to be a heretic] to believe that the contrary of his opinion is true and of faith and nonetheless to dissent from it. For, as Sanchez [reference given] well points out, it is impossible to dissent from an object which one simultaneously and actually judges to be true or judges to be part of a body of belief which is infallibly true. For this reason, neither can it be necessary to know and believe that the contrary is proposed by the Church which has infallible authority in proposing it; for dissent from this judgement would also be impossible, as it would amount to believing something to be false which one simultaneously believed to be proposed by a Church unable to propose anything false - which is obviously self-contradictory, as the terms themselves make clear.

So for someone to be a heretic, i.e. pertinaciously to oppose the authority of the Church, it is enough that (a) the infallible authority of the Church and (b) its definition of the contrary dogma should be proposed to him in such a way that, even if he chose not to believe either, nonetheless he could have done so, having seen the duty to believe both, and having seen that they could not prudently be denied, doubted or hesitated over. For by the very fact of, on the one hand, dissenting, and, on the other hand, denying that the Church has infallible authority in proposing, or - if he grants that the Church has this authority - of denying that the dogma contrary to his opinion has in fact been proposed by the Church, he has already pertinaciously rejected the teaching of the Church sufficiently proposed to him. And this is in fact how heretics do sin - they either do not in fact believe that our Church has infallible authority in proposing or do not believe that dogmas contrary to their position are proposed by [what they take to be] the true Church, as Suarez remarked [reference given]. But because both points are proposed to them in such a way that they can and must believe it, they are said to be, and are, heretics pertinaciously opposed to the authority and teaching of the Church.