Chapter XVI.—Instruction Continued: the True Prophet.

"He, therefore, whose aid is needed for the house filled with the darkness of ignorance and the smoke of vices, is He, we say, who is called the true Prophet, who alone can enlighten the souls of men, so that with their eyes they may plainly see the way of safety. For otherwise it is impossible to get knowledge of divine and eternal things, unless one learns of that true Prophet; because, as you yourself stated a little ago, the belief of things, and the opinions of causes, are estimated in proportion to the talents of their advocates: hence, also, one and the same cause is now thought just, now unjust; and what now seemed true, anon becomes false on the assertion of another. For this reason, the credit of religion and piety demanded the presence of the true Prophet, that He Himself might tell us respecting each particular, how the truth stands, and might teach us how we are to believe concerning each. ^[539] And therefore, before all else, the credentials of the prophet himself must be examined with all care; and when you have once ascertained that he is a prophet, it behoves you thenceforth to believe him in everything, and not further to discuss the particulars which he teaches, but to hold the things which he speaks as certain and sacred; which things, although they seem to be received by faith, yet are believed on the ground of the probation previously instituted. For when once at the outset the truth of the prophet is established on examination, the rest is to be heard and held on the ground of the faith by which it is already established that he is a teacher of truth. And as it is certain that all things which pertain to divine knowledge ought to be held according to the rule of truth, so it is beyond doubt that from none but Himself alone can it be known what is true."