I am currently reading Humility of Heart by Fr. Cajetan da Bergamo. It is an 18th century classic of the spiritual life. As you can tell from the title of my article, I wanted to ask myself something that pertains to my own website and mission: Is it humble to expose heretics? Although Fr. Cajetan lived in a time of relative stability in the Catholic Church, I think he gives an answer that is clear today. The first half of what I have taken from his writings (not exactly about heresy) implies a “No” and the second half implies a “Yes.”

Again, the question is: Is it humble to expose a heretic?

No:

Fr. Cajetan writes:  Who knows if the one I judge and speak ill of may not be dearer to God than I am? Whether another, whom I esteem but little and despise for his physical or moral defects, be not destined to be very happy with God for all eternity? Who knows whether I may not be condemned to the pains of Hell for all eternity? With this uncertainty, how can I then presume to consider myself better than any other?

When I read of St. Paul, the herald of the Holy Ghost and great doctor of the Gentiles—who said of himself that he lived in fear of falling into sin and becoming a castaway after having converted so many thousands of souls to God (“Lest perhaps when I have preached to others, I myself may become a castaway,” 1 Cor. 9:27)—ah, if St. Paul himself should thus fear, who was rapt unto the third Heaven and could say that Christ lived in him, (“and I live now, not I, but Christ liveth in me,” Gal. 2:20), what shall I say of myself, who am so contemptible? At the Day of Judgment, how many shall we see on the right hand of God whom we looked upon as castaways, and how many shall we see on His left, whom we believed to be among His elect!

St. Thomas taught that a man may truthfully say and believe that he is worse than others, partly on account of the hidden defects which he knows that he possesses and partly on account of the gifts of God that are hidden in others.

Another humiliating thought lies in the remembrance of the Judgment to come. Saints tremble at the thought that they will be judged by a God in whose presence not even the Angels are immaculate.

But… Yes:

The truly humble man considers that whatever is good in his material or spiritual nature is like unto the streams that have come originally from the sea and must eventually return to the sea, and therefore he is always careful to render to God all that he has received from God, and neither prays for nor loves nor desires anything except that in all things the name of God be sanctified: “Hallowed be Thy name.” (Matt. 6:9). Humility is not a sickly virtue, timid and feeble, as some imagine; on the contrary, it is strong, magnanimous, generous and constant, because it is founded on truth and justice. The truth consists in knowing what God is and what we are. Justice consists in our recognizing that God, as our Creator, has a right to command us and that we, as His creatures, are bound to obey Him. All the martyrs were perfectly humble because they preferred to die, suffering the most terrible torments, rather than abandon truth and justice. How great their endurance and courage in resisting those who tried to force them to deny Jesus Christ! To contradict others is an effect of pride, whenever we contradict them in order to follow our own unjust and mistaken will; but when our opposition to the creature proceeds from a determination to fulfill the will of the Creator, it is dictated by humility; for by this we confess our indispensable obligation to be subject and obedient to the divine Will. It is for this reason that the proud man is always timid, because his pride is only sustained by the weakness of human nature. And he who is humble is always brave in the exercise of his submission to the Divine Majesty, because he receives his strength through grace. The humble obey men, when in so doing they also obey God; but they refuse obedience to men, when by obeying them they would disobey their God. Reflect upon that answer, as modest as it was magnanimous, given before the elders of Jerusalem by St. Peter and St. John: “If it be just in the sight of God to hear you rather than God, judge ye.” (Acts 4:19).

—Fr. Cajetan (Gaetano) da Bergamo, Fr. Cajetan Mary. Humility of Heart (pp. 35-39.)