At this time (i.e. before 88 B.C.) Cicero also heard the lectures of Diodotus the Stoic, with whom he studied chiefly, though not exclusively, the art of dialectic.[[6]] This art, which Cicero deems so important to the orator that he calls it "abbreviated eloquence," was then the monopoly of the Stoic school. For some time Cicero spent all his days with Diodotus in the severest study, but he seems never to have been much attracted by the general Stoic teaching. Still, the friendship between the two lasted till the death of Diodotus, who, according to a fashion set by the Roman Stoic circle of the time of Scipio and Laelius, became an inmate of Cicero's house, where he died in B.C. 59, leaving his pupil heir to a not inconsiderable property.[[7]] He seems to have been one of the most accomplished
men of his time, and Cicero's feelings towards him were those of gratitude, esteem, and admiration.[[8]]
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]].
The whole two years 79—77 B.C. were spent in the society of Greek philosophers and rhetoricians. The first six months passed at Athens, and were almost entirely devoted to philosophy, since, with the exception
of Demetrius Syrus, there were no eminent rhetorical teachers at that time resident in the city[[14]]. By the advice of Philo himself[[15]], Cicero attended the lectures of that clear thinker and writer, as Diogenes calls him[[16]], Zeno of Sidon, now the head of the Epicurean school. In Cicero's later works there are several references to his teaching. He was biting and sarcastic in speech, and spiteful in spirit, hence in striking contrast to Patro and Phaedrus[[17]]. It is curious to find that Zeno is numbered by Cicero among those pupils and admirers of Carneades whom he had known[[18]]. Phaedrus was now at Athens, and along with Atticus who loved him beyond all other philosophers[[19]], Cicero spent much time in listening to his instruction, which was eagerly discussed by the two pupils[[20]]. Patro was probably in Athens at the same time, but this is nowhere explicitly stated. Cicero must at this time have attained an almost complete familiarity with the Epicurean doctrines.
There seem to have been no eminent representatives of the Stoic school then at Athens. Nor is any mention made of a Peripatetic teacher whose lectures Cicero might have attended, though M. Pupius Piso, a professed Peripatetic, was one of his companions in this sojourn at Athens[[21]]. Only three notable Peripatetics were at this time living. Of these Staseas of Naples, who lived some time in Piso's house, was not then at Athens[[22]]; it is probable, however, from a mention of
him in the De Oratore, that Cicero knew himm through Piso. Diodorus, the pupil of Critolaus, is frequently named by Cicero, but never as an acquaintance. Cratippus was at this time unknown to him.