in atheism; dialectic training had destroyed the sanctity of ethical restraints. When, however, the religious and virtuous Socrates is put forward as a type of both tendencies, our confidence in the comic poet’s accuracy, if not in his good faith, becomes seriously shaken; and his whole tone so vividly recalls the analogous invectives now hurled from press and pulpit against every philosophic theory, every scientific discovery, every social reform at variance with traditional beliefs or threatening the sinister interests which have gathered round iniquitous institutions, that at first we feel tempted to follow Grote in rejecting his testimony altogether. So far, however, as the actual phenomena themselves are concerned, and apart from their generating antecedents, Aristophanes does but bring into more picturesque prominence what graver observers are content to indicate, and what Plato, writing a generation later, treats as an unquestionable reality. Nor is the fact of a lowered moral tone going along with accelerated mental activity either incredible or unparalleled. Modern history knows of at least two periods remarkable for such a conjunction, the Renaissance and the eighteenth century, the former stained with every imaginable crime, the latter impure throughout, and lapsing into blood-thirsty violence at its close. Moral progress, like every other mode of motion, has its appropriate rhythm—its epochs of severe restraint followed by epochs of rebellious license. And when, as an aggravation of the reaction from which they periodically suffer, ethical principles have become associated with a mythology whose decay, at first retarded, is finally hastened by their activity, it is still easier to understand how they may share in its discredit, and only regain their ascendency by allying themselves with a purified form of the old religion, until they can be disentangled from the compromising support of all unverified theories whatever. We have every reason to believe that Greek life and thought did pass through such a crisis during the second half of the fifth century B.C., and we have now to deal with the speculative aspects of that crisis, so far as they are represented by the Sophists. IV.