THREE:This work, as already explained, is to be devoted to mechanical engineering, and in view of the difference of opinion that exists as to what mechanical engineering comprehends, and the different sense in which the term is applied, it will be proper to explain what is meant by it here.No one will deny that the life of the Greeks was stained with foul vices, and that their theory sometimes fell to the level of their practice. No one who believes that moral truth, like all truth, has been gradually discovered, will wonder at this phenomenon. If moral conduct is a function of social life, then, like other functions, it will be subject, not only to growth, but also to disease and decay. An intense and rapid intellectual development may have for its condition a totally abnormal state of society, where certain vices, unknown to ruder ages, spring up and flourish with rank luxuriance. When men have to take women along with them on every new path of enquiry, progress will be considerably retarded, although its benefits will ultimately be shared among a greater number, and will be better insured against the danger of a violent reaction. But the work that Hellas was commissioned to perform could not wait; it had to be accomplished in a few generations, or not at all. The barbarians were forcing their way in on every side, not merely with the weight of invading armies, but with the deadlier pressure of a benumbing superstition, with the brute-worship of Egypt and the devil-worship of Phoenicia, with57 their delirious orgies, their mutilations, their crucifixions, and their gladiatorial contests. Already in the later dramas of Euripides and in the Rhodian school of sculpture, we see the awful shadow coming nearer, and feel the poisonous breath of Asia on our faces. Reason, the reason by which these terrors have been for ever exorcised, could only arrive at maturity under the influence of free and uninterrupted discussion carried on by men among themselves in the gymnasium, the agora, the eccl��sia, and the dicastery. The resulting and inevitable separation of the sexes bred frightful disorders, which through all changes of creed have clung like a moral pestilence to the shores of the Aegean, and have helped to complicate political problems by joining to religious hatred the fiercer animosity of physical disgust. But whatever were the corruptions of Greek sentiment, Greek philosophy had the power to purge them away. ��Follow nature�� became the watchword of one school after another; and a precept which at first may have meant only that man should not fall below the brutes, was finally so interpreted as to imply an absolute control of sense by reason. No loftier standard of sexual purity has ever been inculcated than that fixed by Plato in his latest work, the Laws. Isocrates bids husbands set an example of conjugal fidelity to their wives. Socrates had already declared that virtue was the same for both sexes. Xenophon interests himself in the education of women. Plato would give them the same training, and everywhere associate them in the same functions with men. Equally decisive evidence of a theoretical opposition to slavery is not forthcoming, and we know that it was unfortunately sanctioned by Plato and Aristotle, in this respect no better inspired than the early Christians; nevertheless, the germ of such an opposition existed, and will hereafter be pointed out.