Portrait Of Epicurus (341-27O B.C.), based on a commemorative statue of the mid third century B.C. The
founder of the Epicurean school of philosophy taught that pleasure (that is, freedom from pain and peace
of mind) was the goal of life. His 'atomic' theory of the universe inspired Lucretius' great poem De return
natura in the first century B.C.
The Stoics were not traditionalists. The school's long history divides into three phases, Old, Middle, and
Late. The Middle Stoa, whose chief ornaments were Panaetius of Rhodes (c. 185-109) and Posidonius of
Apamea (135-51), substantially altered the emphasis of the school. So, too, did the Late Stoa, which is
represented for us by Seneca (below, pp.663 f), Epictetus (pp. 708 ff.), and Marcus Aurelius (pp. 711 ff.)
from the first two centuries A.D.; Nor was the Old Stoa marked by doctrinal uniformity. There were
renegades, of whom the most important was Ariston of Chios. He limited his concerns to ethics, rejecting
physics and maintaining that 'dialectical reasonings are like spiders' webs - they seem to display some
artistry but are in fact useless'. Chrysippus himself 'differed on many points from Zeno and also from
Cleanthes, to whom he would often say that he only needed to be taught the theories and would discover