Be this as it may, it may be fairly assumed that the deep injustice of the Athenian republic in thus removing from a scene of usefulness, and of harmless, if somewhat unpopular banter, this great teacher, rankled very deeply in the heart of Plato. It is the real source of that most favourite of all topics, that theme on which all his disquisitions on moral worth turn--ἀδικία, or injustice. This may be called the key-note of the _Republic_, as it is, in fact, of the _Gorgias_ and the _Protagoras_, not to mention the very numerous passages in other dialogues. Plato is ever fond of putting in the mouth either of Socrates or his friends passages which he could hardly have uttered, for they have a clear reference to the want of success in his 'Apologia' at the trial, through the non-use of clap-trap, δημηγορία, and ῥητορική. (See _Gorgias_, p. 486, A.; _Theætet._, p. 172, C., 174, C.) Modern writers on morals or casuistry do not, directly, at least, take _injustice_ as the basis of all their teaching, even though, in a sense, all vice is a form of injustice, either to oneself or one's neighbour. The fate of Socrates, and the reasons of it, bear some analogy to the unpopularity and harsh treatment which great moral reformers have received in almost every country and under every form of government. The alleged interference both in public and private affairs, the resistance to popular indulgences and vicious pleasures, and the persistent _lecturing_ men of deadened conscience, are more than human nature is prepared to stand, if pressed beyond a certain point. In the _Theætetus_ (p. 149, A.), Socrates sums up the popular odium against himself in these words: 'They say of me that I am an exceedingly strange being, who drives men to their wits' end;' and in the _Apology_ he distinctly traces the διαβολὴ, or misrepresentation of his motives and practices, to the ridicule brought upon him (some twenty years before) by the _Clouds_ of Aristophanes. But the real cause of his unpopularity was the fearless way in which he told unpalatable truths: as that men should care for their souls more than for their money, and that a life without self-examination was not worth the living, ὁ ἀνεξέταστος βίος οὐ βιωτὸς ἀνθρώπῳ (_Apol._, p. 29, E., 36, C., 38, A.) This was stronger doctrine, at least so far as concerns the preference of money to all religious cares, than could safely be preached now-a-days from a pulpit in London. We remember the case of a clergyman being quite recently bemobbed and rather roughly treated because he attempted to do so. No! the sophist and the Christian moralist alike must give way when resistance to the career of human feeling is pressed too far, just as a river will surmount or wash away altogether the dam constructed to check its course.