Cleanthes was born at Assos in the Troas, about 300 b.c.; he came to Athens at an early age, and became the pupil of Zeno, whom at his death he succeeded in his school. He differed from his master in regarding the soul as immortal, and approximated to the Cynics in denying that pleasure was agreeable to nature, or in any respect good. He died of voluntary starvation at the age of eighty.
Chrysippus was born b.c. 280, at Soli in Cilicia. He came at an early age to Athens, and became a pupil of Cleanthes; and among the later Stoics he was more regarded than either Zeno or Cleanthes. He died b.c. 207.
His doctrines do not appear to have differed from those of Zeno; only that, from feeling the dangerous influence of the Epicurean principles, he endeavoured to popularize the Stoic ethics.
Epicurus was an Athenian of the Attic demos Gargettus, whence he is sometimes simply called the Gargettian. He was, however, born at Samos, b.c. 342, and did not come to Athens till the age of eighteen, when he found Xenocrates at the head of the Academy, and by some authors is said to have become his pupil, though he himself would not admit it (Cic. de Nat. Deor. i. 26). At the outbreak of the Samian war he crossed over to Colophon, where he collected a school. It is said that the first thing that excited him to the study of [pg xxviii] philosophy was the perusal of the works of Democritus while he resided at Colophon. From thence he went to Mitylene and Lampsacus, and b.c. 306 he returned to Athens, and finally established himself as a teacher of philosophy. His own life was that of a man of simple, pure, and temperate habits. He died of the stone, b.c. 270, and left Hermarchus of Mitylene as his successor in the management of his school.
None of his works have come down to us. With regard to his philosophical system, in spite of his boast of being self-taught and having borrowed from no one, he clearly derived the chief part of his natural philosophy from Democritus, and of his moral philosophy from Aristippus and the Cyrenaics. He considered human happiness the end of all philosophy, and agreed with the Cyrenaics that pleasure constituted the greatest happiness; still this theory in his hands acquired a far loftier character; for pleasure, in his idea, was not a mere momentary and transitory sensation, but something lasting and imperishable, consisting in pure mental enjoyments, and in the freedom from pain and any other influence which could disturb man's peace of mind. And the summum bonum, according to him, consisted in this peace of mind; which was based upon correct wisdom (φρόνησις).
In his natural philosophy he embraced the atomic theories of Democritus and Diagoras, carrying them even further than they themselves had done, to such a degree that he drew upon himself the reproach of Atheism. He regarded the Gods themselves as consisting of atoms, and our notions of them as based upon the images (εἴδωλα) which are reflected from them, and so pass into our minds. And he believed that they exercised no influence whatever on the world, or on the actions or fortunes of man.
Theodorus was a native of Cyrene, who flourished about b.c. 320. He was of the Cyrenaic sect, and the founder of that branch of it which was called after him, the Theodorean; though we scarcely know in what his doctrines differed from those of Aristippus, unless they were, if possible, of a still more lax character. He taught, for instance, that there was nothing really wrong or disgraceful in theft, adultery, or [pg xxix] sacrilege; but that they were branded by public opinion to restrain fools. He is also reproved with utter atheism; and Cicero classes him with Diagoras, as a man who utterly denied the existence of any Gods at all.
Pyrrho was a contemporary of Alexander the Great, whose expedition into Asia he joined. He appears, as far as his philosophy went, to have been an universal sceptic. He impeached, however, none of the chief principles of morality, but, regarding Socrates as his model, directed all his endeavours towards the production in his pupils of a firm well-regulated moral character.
Crantor was a native of Soli in Cilicia; we do not know when he was born or when he died, but he came to Athens before b.c. 315. He was the first of Plato's followers who wrote commentaries on the works of his master. He died of dropsy, and left Arcesilaus his heir.
Arcesilaus, or Arcesilas, flourished about b.c. 280; he was born at Pitane, but came to Athens and became the pupil of Theophrastus and of Crantor, and afterwards of some of the more sceptical philosophers. On the death of Crantor he succeeded to the chair of the Academy, in the doctrines of which he made so many innovations that he is called the founder of the New Academy. What his peculiar views were is, however, a matter of great uncertainty. Some give him the credit of having restored the doctrines of Plato in an uncorrupted form; while, according to Cicero, on the other hand, (Acad. i. 12,) he summed up all his opinions in the statement that he knew nothing, not even his own ignorance. He, and the New Academy, do not, however, seem to have doubted the existence of truth in itself, but only the capacity of man for arriving at the knowledge of it.