In a recent post, Dr. Peter Chojnowski pulls the following quote from Cardinal Louis Billot regarding material and formal heretics (emphasis by Dr. Chojnowski):
“Heretics are divided into formal and material. Formal heretics are those to whom the authority of the Church is sufficiently known; while material heretics are those who, being in invincible ignorance of the Church herself, in good faith choose some other guiding rule. So the heresy of material heretics is not imputable as sin and indeed it is not necessarily incompatible with that supernatural faith which is the beginning and root of all justification. For they may explicitly believe the principal articles, and believe the others, though not explicitly, yet implicitly, through their disposition of mind and good will to adhere to whatever is sufficiently proposed to them as having been revealed by God. In fact they can still belong to the body of the Church by desire and fulfil the other conditions necessary for salvation. Nonetheless, as to their actual incorporation in the visible Church of Christ, which is our present subject, our thesis makes no distinction between formal and material heretics, understanding everything in accordance with the notion of material heresy just given, which indeed is the only true and genuine one. For, if you understand by the expression material heretic one who, while professing subjection to the Church’s Magisterium in matters of faith, nevertheless still denies something defined by the Church because he did not know it was defined, or, by the same token, holds an opinion opposed to Catholic doctrine because he falsely thinks that the Church teaches it, it would be quite absurd to place material heretics outside the body of the true Church; but on this understanding the legitimate use of the expression would be entirely perverted. For a material sin is said to exist only when what belongs to the nature of the sin takes place materially, but without advertence or deliberate will. But the nature of heresy consists in withdrawal from the rule of the ecclesiastical Magisterium and this does not take place in the case mentioned [of someone who is resolved to believe all that the Church teaches but makes a mistake as to what her teaching consists in], since this is a simple error of fact concerning what the rule dictates. And therefore there is no scope for heresy, even materially.”
(Cardinal Louis Billot S.J., De Ecclesia Christi, 4th edition, pp.289-290. Translated by John S. Daly)
I am glad that Dr. Chojnowski posted this quote because I have heard it said so many times, even amongst Traditional Catholics, that a Catholic who holds a heresy, even without him knowing it, is a “material heretic”. Wrong! Wrong! Wrong! This is a misuse of the term “material heretic”. A “material heretic” is one who admits he is not a Catholic (e.g., an Anglican), but acts in good faith and is of such good will that he would be ready to become a Catholic if he came to know the truth about the Catholic Church being the one true Church of Jesus Christ.
In regards to one in the Conciliar Church, it is wrong to apply the term “material heretic” to him. He may hold to a teaching that is matter for heresy, but unlike the Anglican, he truly believes himself to be a Catholic and submits himself to the same Magisterium and hierarchy as does the Traditional Catholic, despite his adhering to a false religion. Hence, he is not a “material heretic”.