Nevertheless it is possible that a man’s practical reason may sometimes fail, not recognizing God’s will plainly and clearly as such or being involved in invincible error. In such a case he is not bound to the objective law, but to that which appears to his conscience to be God’s will, although the judgment of his conscience be objectively false. No less an authority than St. Thomas stresses this obligation of the erroneous conscience. Even in the case of so vital a matter as belief in Christ a man would act wrongly who should profess this faith against the judgment of his (erroneous) conscience (Summa, Prima Secundae, Q. xix, A. 5; cf. Quod lib. iii, 27).

May a Catholic ever be justified in refusing to obey the church? Let us treat this question more fully, for it illustrates in a unique way the decisive importance which the Church assigns to conscience, and the relation of the subjective dictates of conscience to the objective ordinances of law.

Being conscious that she is the infallible teacher of revealed truth and the sole effective institute for salvation, the Church can never admit that Catholics are in the same condition as those who have not yet come to the faith, so that they can have just cause for regarding the faith which they have already received by the authoritative teaching of the Church as doubtful, and for withholding their assent until they have completed a scientific demonstration of the credibility and truth of their faith.[1]

Therefore, according to the Vatican Council, the spiritual relation of the Catholic to the great kingdom of supernatural reality and its problems is profoundly different from that of the non-Catholic. The Council lays it down that the divine evidences, to which the Church and the Church only can appeal, are too many (multa) and too wonderful (mira), for a Catholic’s faith to be disturbed by a serious and objective doubt. The Church’s claim to the truth is so deeply set in the hard granite of historical facts and of logical consistency, and is so intimately bound-up with the ultimate and profoundest requirements of conscience, with its reverence before that which is holy and divine, that it can stand fast and prevail over any possible inquiry, whether past, present or future. Moreover the Catholic cannot become the prey of any merely subjective doubt, resting upon false presuppositions or erroneous deductions, so long as he does not proudly and arrogantly exclude that light of grace which is refused to no man of good will.