The death of Aristotle marks the end of the Golden Age of Greek
philosophy. From Thales to Socrates was the period of beginnings; from
Socrates to Aristotle, the period of highest perfection; with the
opening of the post-Aristotelian period begins the age of decay and
dissolution. To this third period belong the pantheism of the
Stoics, the materialism of the Epicureans, and the final
relaxation of all earnest philosophical thought, culminating in the
absolute scepticism of the Pyrrhonists. The period of highest
perfection in philosophy was also the period of the political
greatness of Greece, and the causes which brought about the political
downfall of Greece are in part accountable for the decay of Greek
Sixteen years before the death of Aristotle, the battle of Chaeronea
(338 B.C.) was fought, -- the battle in which the doom of Greece was
sealed. There followed a series of unsuccessful attempts to shake off
the Macedonian yoke. In vain did Demosthenes strive to arouse in the
breasts of the Athenians the spirit of the days of Marathon and
Thermopylae; the iron hand of military despotism crushed the last
manifestations of patriotism. Then the Roman came, to succeed the
Macedonian, and Greece, the fair home of philosophy in the West, was
made a province of a vast military and commercial empire.
The loss of political freedom was followed by a period of torpor of the
creative energies of the Greek mind.  Speculation, in the highest
sense of constructive effort, was no longer possible and philosophy
became wholly practical in its aims. Theoretical knowledge was
valued not at all, or only in so far as it contributed to that bracing
and strengthening of the moral fiber
which men began to seek in philosophy, and for which alone philosophy
began to be studied. Philosophy thus came to occupy itself with ethical
problems, and to be regarded as a refuge from the miseries of life.
When men ceased to count it an honor to be a citizen of Hellas, they
turned to philosophy in order to become citizens of the world; and so
philosophy assumed a more cosmopolitan character. Imported into
the Roman Empire, it failed at first to take root on Roman soil because
in the Latin contempt of the Graeculus was included a contempt
for all things Greek. Gradually, however, philosophy gained ascendency
over the Roman mind, while in turn the Roman love of the practical
asserted its influence on Greek philosophy.
 This opinion of Zeller and others is controverted by Benn, The
Greek Philosophers, Vol. 1, p. xi.
All these influences resulted in (1) a disintegration of the
distinctively Greek spirit of philosophy and the substitution of a
cosmopolitan spirit of eclecticism; (2) a centering of philosophical
thought around the problems of human life and human destiny; and (3)
the final absorption of Greek philosophy in the reconstructive efforts
of the Greco-Oriental philosophers of Alexandria.
But, while metaphysics and physics were neglected in this
anthropocentric movement of thought, the mathematical sciences,
emancipating themselves from philosophy, began to flourish with new
vigor. The astronomers of Sicily and later those of Alexandria stand
out of the general gloom of the period as worthy representatives of the
Greek spirit of scientific inquiry.
The principal schools of this period are: (1) the Stoics, (2) the
Epicureans, (3) the Sceptics, (4) the Eclectics, (5) the mathematicians
and astronomers. A separate chapter will be devoted to The Philosophy
of the Romans.