And so in any religion this is done, especially by those who can not read and write or do not have anything to read. But it should have been observed that in this matter it is not sufficient that the teachers of any religion should have the power, because of very exact powers of judgment and avowed experience, of distinguishing the true from the false. Indeed it ought to be very certain to others, with powers of judgment no less exact, that those teachers have not only the ability to distinguish the true from the false, but the desire as well, and indeed we ought to be especially certain that he who professes such a knowledge and desire is neither deceived nor wishes to be. And what choice shall we make here among so many teachers so much at variance in even one eminent sect? For when we look at our comrades and associates, who disagree on many subjects, although they are most friendly in other respects, one of the two disputants will maintain his opinion on account of some defect, either because he has not a correct understanding of the matter, and lacks the power of judgment, or because he does not wish to give up, and so does not desire to confess the truth. But although it might be matters of secondary importance in which this happened, nevertheless the result will be that they will be mistrusted in other matters also. Each doubtless is in possession of one truth, and he who gives this up in one place, either from a defect of judgment or a wrong desire is deservedly mistrusted of doing the same thing in other cases. Therefore, that you may judge of the ability and honesty of any teacher in religion, first, it is necessary for you to be just as able as he; for otherwise he will be able to impose on you very easily, and, moreover, if he is unknown to you, he will need the testimony of others, and these again of others, and so on indefinitely; not only in regard to his truthfulness, that he really taught such doctrines, but in regard to his honesty, that he did this without deceit. And the same method must at once be employed in regard to the witnesses of his honesty and his teachings. But where will you place an end to this? It is not enough that such discussions have already taken place among others; you must consider how well this has been done. For the ordinary proofs which are set forth are neither conclusive nor manifest, and prove doubtful matters by others more doubtful, so that, like those who run in a circle, you return to the starting point. In order that it may be manifest whether any one is a teacher of a true religion or an impostor, there is need either of personal knowledge, which we can not have in the case of the three great founders of the religions of Judaism, Christianity and Mahometanism, inasmuch as they lived in far distant places and died long before our time; or of the knowledge of others, which, if any one imparts it to you, we call testimony.