At the time when Carneades delivered his lectures, the morality of Rome resembled that of Sparta during her great conflict with Athens, as characterised by one of the speakers in the Melian Dialogue. Scrupulously honourable in their dealings with one another, in their dealings with foreign nations her citizens notoriously identified justice with what was agreeable or advantageous to themselves. The arguments of the Academic philosopher must, therefore, have been doubly annoying to the leaders of the State, as a satire on its public policy and as a source of danger to the integrity of its private life. In this respect, old Cato was a type of the whole race. In all transactions with his fellow-citizens, and in every office undertaken on behalf of the community, his honesty was such that it became proverbial. But his absolute disregard of international justice has become equally proverbial through the famous advice, reiterated on every possible occasion, that an unoffending and unwarlike city should be destroyed, lest its existence should at some future time become a source of uneasiness to the mistress of the world. Perhaps it was a secret consciousness of his own inconsistency which prevented him from directly proposing that Carneades should not be allowed to continue his lectures. At any rate, the ex-Censor contented himself with moving that the business on which the Athenian envoys had come should be at once concluded, that they might return to their classes at Athens, leaving the youth of Rome to seek instruction as before from the wise conversation and example of her public men.[214] We are not told whether his speech on this occasion wound up with the usual formula, _caeterum, Patres Conscripti, sententia mea est Carthaginem esse delendam_; but as it is stated that from the year 175 to the end of his life, he never made a motion in the Senate that was not terminated by those words, we are entitled to assume that he did not omit them in the present instance. If so, the effect must have been singularly grotesque; although, perhaps, less so than if attention had been drawn to the customary phrase by its unexpected absence. At any rate, Carneades had an opportunity of carrying back one more illustration of ethical inconsistency wherewith to enliven his lectures on the ‘vanity of dogmatising’ and the absolute equilibrium of contradictory opinions. It has been mentioned that Carneades was the head of the Academic school. In that capacity, he was the lineal inheritor of Plato’s teaching. Yet a public apology for injustice, even when balanced by a previous panegyric on its opposite, might seem to be of all lessons the most alien from Platonism; and in a State governed by Plato’s own laws, it would certainly have been punishable with death. To explain this anomaly is to relate the history of Greek scepticism, which is what we shall now attempt to do. II.