845. Positive doubt is the state of mind in which one decides, on account of some difficulty against faith, that the latter is really doubtful and uncertain, and that assent cannot be given to either side. With regard to such a state of mind note: (a) If this judgment is formed by a Catholic, it is heretical; for his faith, as he knows and admits, is the true faith, revealed and proposed as absolutely certain. Hence, although he does not deny the faith, he does positively judge that what is revealed by God and proposed infallibly by the Church as certain, is not certain, and thus in his intellect there is pertinacious error. (b) If this judgment is formed by a non-Catholic, it is likewise heretical, if the truth doubted belongs to divine or Catholic faith, for we are now considering the formal heretic who belongs to a non-Catholic sect against conviction; but it is not heretical, if the doctrine doubted belongs only to what is wrongly considered in his sect as divine faith, or to what may be called Protestant faith (i.e., the official confession of his religion), for he does not profess to accept his church as an infallible interpreter. 846. The doubts We have been just discussing are the passing doubts that come to those who are believers, or who consider themselves believers. There are also doubts that are permanent, and that are held by those who class themselves, not as believers, but as doubters or agnostics. Some of these sceptics doubt all religious creeds, holding that it is works and not beliefs that matter. This doctrine amounts to infidelity, since it rejects Christian faith entirely. Others profess Fundamentalism, which accepts a few Christian beliefs and considers the others as optional, pretending that the true faith cannot be recognized amid so much diversity of opinions. This doctrine is heretical, since it accepts some and rejects others of the articles of faith. 847. Credulity and Rationalism.--Opposed in special ways to the material and formal objects of faith are credulity and errors about the existence and nature of revelation.