In the year 88 B.C. the celebrated Philo of Larissa, then head of the Academic school, came to Rome, one of a number of eminent Greeks who fled from Athens on the approach of its siege during the Mithridatic war.  Philo, like Diodotus, was a man of versatile genius:  unlike the Stoic philosopher, he was a perfect master both of the theory and the practice of oratory.  Cicero had scarcely heard him before all inclination for Epicureanism was swept from his mind, and he surrendered himself wholly, as he tells us, to the brilliant Academic.[9] Smitten with a marvellous enthusiasm he abandoned all other studies for philosophy.  His zeal was quickened by the conviction that the old judicial system of Rome was overthrown for ever, and that the great career once open to an orator was now barred.[10]

We thus see that before Cicero was twenty years of age, he had been brought into intimate connection with at least three of the most eminent philosophers of the age, who represented the three most vigorous and important Greek schools.  It is fair to conclude that he must have become thoroughly acquainted with their spirit, and with the main tenets of each.  His own statements, after every deduction necessitated by his egotism has been made, leave no doubt about his diligence as a student.  In his later works he often dwells on his youthful devotion to philosophy.[11] It would be unwise to lay too much stress on the intimate connection which subsisted between the rhetorical and the ethical teaching of the Greeks; but there can be little doubt that from the great rhetorician Molo, then Rhodian ambassador at Rome, Cicero gained valuable information concerning the ethical part of Greek philosophy.

During the years 88—­81 B.C., Cicero employed himself incessantly with the study of philosophy, law, rhetoric, and belles lettres.  Many ambitious works in the last two departments mentioned were written by him at this period.  On Sulla’s return to the city after his conquest of the Marian party in Italy, judicial affairs once more took their regular course, and Cicero appeared as a pleader in the courts, the one philosophic orator of Rome, as he not unjustly boasts[12].  For two years he was busily engaged, and then suddenly left Rome for a tour in Eastern Hellas.  It is usually supposed that he came into collision with Sulla through the freedman Chrysogonus, who was implicated in the case of Roscius.  The silence of Cicero is enough to condemn this theory, which rests on no better evidence than that of Plutarch.  Cicero himself, even when mentioning his speech in defence of Roscius, never assigns any other cause for his departure than his health, which was being undermined by his passionate style of oratory[13].