Jesus, it is said, in giving the Sermon on the Mount, taught as one having authority, and not as the Scribes. What was his authority, then? Not official authority, for he was not yet known to be the Christ, hardly yet known to be a prophet. Not merely the _authority_ coming from an imposing manner; not an authoritative air, or tone, or manner, certainly. That was precisely the tone and manner which the Scribes _did_ have in _their_ teaching. But the authority is in the Sermon itself. Its truths are so wonderfully distinct and self-evident, they carry conviction with them. Jesus sees so plainly all that he says—there is no hesitation, no obscurity, no perhapses in his language. He is like one describing what is before his eyes, what he knows to be true because he sees it while he is saying it. It is, in short, the authority which always attends knowledge. He who knows anything, and can speak with certainty, carries conviction with him, though we do not suppose him to be infallible, nor is it thought necessary to believe him so, in order to give to him this authority. By such examples, we see that in earthly matters of the very highest importance we ascribe authority without supposing infallibility. Now, if we analyze the source of this authority, we shall find that it comes, first, from the testimony of others, and, secondly, from our own experience. Leatherstocking comes recommended to the travellers as a skilful and faithful guide, and they trust him, at first, on the simple ground of that recommendation. But they do not trust him entirely or fully on that ground. They watch him while they trust him,—perhaps we ought rather to say, they _try_ him, than that they _trust_ him. But, after they have tried him day by day, week by week, and find him always skilful, always faithful, they come to place a more and more implicit trust in his guidance; he becomes more and more an authority. So the pilot comes at first recommended only by his office. His office implies the testimony of those who ought to know that he is able to guide the vessel into the harbor. But if, besides this, there is some one on board who knows his ability and fidelity by previous experience, and says, “We are all safe now; this is the famous John Smith or William Brown, the best pilot in the harbor,” then everybody is ready to trust him more entirely. Knowledge and fidelity, _not_ infallibility, these make a man an authority to others in things pertaining to this life—knowledge and fidelity, evidenced to us, first by the testimony of others, and secondly by our own experience. Testimony leads us to _try_ a man and trust him partially, trust him, but watch him. Add to this our own experience of his knowledge and fidelity, and we trust him wholly.