We have seen how Carneades, alike in his theory of probability and in his ethical eclecticism, had departed from the extreme sceptical standpoint. His successor, Clitomachus, was content with committing the doctrines of the master to writing. A further step was taken by the next Scholarch, Philo, who is known as the Larissaean, in order to distinguish him from his more celebrated namesake, the Alexandrian Jew. This philosopher asserted that the negations of the New Academy were not to be taken as a profession of absolute scepticism, but merely as a criticism on the untenable pretensions of the Stoa. His own position was that, as a matter of fact, we have some certain knowledge of the external world, but that no logical account can be given of the process by which it is obtained—we can only say that such an assurance has been naturally stamped on our minds.[254] This is the theory of intuitions or innate ideas, still held by many persons; and, as such, it marks a return to pure Platonism, having been evidently suggested by the semi-mythological fancies of the _Meno_ and the _Phaedrus_. With Philo as with those Scotch professors who long afterwards took up substantially the same position, the leading motive was a practical one, the necessity of placing morality on some stronger ground than that of mere probability. Neither he nor his imitators saw that if ethical principles are self-evident, they need no objective support; if they are derivative and contingent, they cannot impart to metaphysics a certainty which they do not independently possess. The return to the old Academic standpoint was completed by a much more vigorous thinker than Philo, his pupil, opponent, and eventual successor, Antiochus. So far from attempting any compromise with the Sceptics, this philosopher openly declared that they had led the school away from its true traditions; and claimed for his own teaching the merit of reproducing the original doctrine of Plato.[255] In reality, he was, as Zeller has shown, an eclectic.[256] It is by arguments borrowed from Stoicism that he vindicates the certainty of human knowledge. Pushing the practical postulate to its logical conclusion, he maintains, not only that we are in possession of the truth, but also—what Philo had denied—that true beliefs bear on their face the evidence by which they are distinguished from illusions. Admitting that the senses are liable to error, he asserts the possibility of rectifying their mistakes, and of reasoning from a subjective impression to its objective cause. The Sceptical negation of truth he meets with the familiar argument that it is suicidal, for to be convinced that there can be no conviction is a contradiction in terms; while to argue that truth is indistinguishable from falsehood implies an illogical confidence in the validity of logical processes; besides involving the assumption that there are false appearances and that they are known to us as such, which would