elucidation given in 1596 by Petrus Valentia in his book entitled _Academica_ (pp. 313--316 of the reprint by Orelli). With regard to (3), it it not difficult to see wherein Philo's "lie" consisted. He denied the popular view of Arcesilas and Carneades, that they were apostles of doubt, to be correct (12). I may add that from the mention of Philo's ethical works at the outset of Stobaeus' _Ethica_, he would appear to have afterwards left dialectic and devoted himself to ethics. What is important for us is, that Cic. never seems to have made himself the defender of the new Philonian dialectic. By him the dialectic of Carneades is treated as genuinely Academic. _Revolvitur_: cf. _De Div._ II. 13, also 148 of this book. _Eam definitionem_: it is noteworthy that the whole war between the sceptics and the dogmatists was waged over the definition of the single sensation. Knowledge, it was thought, was a homogeneous compound of these sense atoms, if I may so call them, on all hands it was allowed that _all_ knowledge ultimately rests on sense; therefore its possibility depends on the truth of the individual perception of sense. §§19--29. Summary. If the senses are healthy and unimpaired, they give perfectly true information about external things. Not that I maintain the truth of _every_ sensation, Epicurus must see to that. Things which impede the action of the senses must always be removed, in practice we always do remove them where we can (19). What power the cultivated senses of painters and musicians have! How keen is the sense of touch! (20). After the perceptions of sense come the equally clear perceptions of the mind, which are in a certain way perceptions of sense, since they come through sense, these rise in complexity till we arrive at definitions and ideas (21). If these ideas may possibly be false, logic memory, and all kinds of arts are at once rendered impossible (22). That true perception is possible, is seen from moral action. Who would act, if the things on which he takes action might prove to be false? (23) How can wisdom be wisdom if she has nothing certain to guide her? There must he some ground on which action can proceed (24). Credence must be given to the thing which impels us to action, otherwise action is impossible (25). The doctrines of the New Academy would put an end to all processes of reasoning. The fleeting and uncertain can never be discovered. Rational proof requires that something, once veiled, should be brought to light (26). Syllogisms are rendered useless, philosophy too cannot exist unless her dogmas have a sure basis (27). Hence the Academics have been urged to allow their _dogma_ that perception is impossible, to be a certain perception of their minds. This, Carneades said, would be inconsistent, since the very dogma excludes the supposition that there can be _any_ true perception (28). Antiochus