21. Another warning for confessors is this, that if it should happen (and it tends to happen rather often) that the minister of confession hears something from his penitents which deserves to be specially investigated, he should beware of responding by intuition, but should devote suitable time and thought to the matter before settling it. It would certainly be desirable that every confessor should be endowed with what is called "eminent" knowledge, but since this is given to few men, it is wholly necessary that each be provided with at least competent knowledge. More cannot be expected: since moral theology deals with so many important questions which depend on a knowledge of the sacred canons and the apostolic constitutions, it is obviously a hard task for anyone to know all these well and immediately to solve every question as those men often do who excel in eminent knowledge. It will then be sufficient if confessors of lesser mark duly settle the more difficult questions by consulting books. Our predecessor Innocent IV wisely observes: "We consider a knowledge eminent if it can discuss and define subtle problems and quickly find their solutions. But that man has an average knowledge who can investigate matters in a certain manner; although he cannot answer all questions, he can search out the truth in books and so does not arrive at all his solutions quickly" (in Commentariis ad Cap., Cum in cunctis, no. 2, under the heading de electione, et electi potestate. So when a more difficult question or a new kind of deed is reported to the confessor and he must consequently consult books, he must do so carefully and selectively. For it is well known that among so many writings there are some whose opinions and assertions do not well agree with the simplicity of the Gospel and the teaching of the holy Fathers. "Many opinions advocate a relaxation of Christian discipline and bring ruin to souls, some being old opinions revived, others newly invented, and the great license of rank minds grows daily more extravagant. By this means, a way of thinking completely at variance with the simplicity of the Gospel and the teaching of the holy Fathers has crept in concerning matters of conscience. If the faithful should adopt it as correct, a mighty corruption of the Christian life would ensue", to quote Our predecessor Alexander VII (decree published September 7, 1665). On this subject We do not want to use plainer speech; We do not want to touch on the disputed questions of the trustworthiness of authors and the soundness of their doctrine. It will be enough to advise confessors not to rely on their own opinion in a doubtful matter. Before judging the case they should refer to as many books as possible, especially those with more substantial doctrine, and then support the opinion which reason suggests and authority confirms. This is exactly what We taught in Our encyclical on usury where We wrote: "They should not cleave excessively to their own private opinions, but before giving an answer they should examine many authors who are especially commended and then take the side which they see is upheld both by reason and authority" (Bullarii nostri, tome 1, ord. 143, sect. 8). We repeat this advice now. For Our statement is not limited to matters of usury, but refers also to all matters which can in any way contribute to the sacramental forum or the proper direction of consciences.