[36] In Plato's dialogue upon the duties of religious worship, a passage occurs, the design of which appears to be, to show that man could not, of himself, learn either the nature of the gods, or the proper manner of worshipping them, unless an instructor should come from heaven. The following remarkable passage occurs between Socrates and Alcibiades:-- _Socrates._--To me it appears best to be patient. It is necessary to wait till you learn how you ought to act towards the gods, and towards men. _Alcibiades._--When, O Socrates, shall that time be? and who shall instruct me? for most willingly would I see this person, who he is. _Socrates._--He is one who cares for you; but, as Homer represents Minerva as taking away darkness from the eyes of Diomedes, that he might distinguish a god from a man: so it is necessary that he should first take away the darkness from your mind, and then bring near those things by which you shall know good and evil. _Alcibiades._--Let him take away the darkness, or any other thing, if he will; for whoever this man is, I am prepared to refuse none of the things which he commands, if I shall be made better.--_Platonis Alcibiad._ ii. It is strange that among philosophers of succeeding ages there has not been wisdom sufficient to discover, from the constitutional necessities of the human spirit, that demand for the instruction and aid of the Messiah which Socrates and Plato discovered, even in a comparatively dark age. There are two insuperable difficulties which would for ever hinder the restoration of mankind to truth and happiness from being accomplished by human means. The first, which has been already alluded to, is that human instruction, as such, has no power to bind the conscience. Even if man were competent to discover all the truth necessary for a perfect rule of conduct, yet that truth would have no reformatory power, because men could never feel that truth was obligatory which proceeded from merely human sources. It is an obvious principle of our nature that the conscience will not charge guilt on the soul for disobedience, when the command proceeds from a fellow man who is not recognised as having the prerogative and the right to require submission. And besides, as men's minds are variously constituted, and of various capacities, there could be no agreement in such a case concerning the question, 'What is truth?' As well might we expect two schoolboys to reform each other's manners in school, without the aid of the teacher's authority, as that men can reform their fellows without the sanction of that authority which will quicken and bind the conscience. The human conscience was made to recognise and enforce the authority of God; and unless there is belief in the Divine obligation of truth, conscience refuses to perform its office.