During the Mithradatic wars Philo left Athens and took up his residence in Rome c. 88 BC. In Rome he lectured on rhetoric and philosophy, and collected around him many eminent pupils, amongst whom Cicero was the most famous and the most enthusiastic.
Philo was the last undisputed scholarch of the Academy in direct succession from Plato. After his death in 84/83 BC, the Academy seceded into rivalling factions and eventually disappeared until the Neoplatonist revival.
He maintained that by means of conceptive notions (katalêptikê phantasia) objects could not be comprehended (akatalêpta), but were comprehensible according to their nature. How he understood the latter, whether he referred to the evidence and accordance of the sensations which we receive from things, or whether he had returned to the Platonic assumption of an immediate spiritual perception, is not clear. In opposition to his disciple Antiochus, he would not admit a separation of an Old and a New Academy, but would rather find the doubts of scepticism even in Socrates and Plato, and not less perhaps in the New Academy the recognition of truth which burst through its scepticism. At least on the one hand, even though he would not resist the evidence of the sensations, he wished even here to meet with antagonists who would endeavour to refute his positions i.e. he felt the need of subjecting afresh what he had provisionally set down in his own mind as true to the examination of scepticism; and on the other hand, he did not doubt of arriving at a sure conviction respecting the ultimate end of life.