GREEK PHILOSOPHY - II.
§ 13 -
The Old Academy
To the Academy in various periods of its
existence various names have been applied. As it was in the
period immediately after Plato's death, it is known as the Old
Academy. The names Middle Academy and New Academy
apply to it in later periods of its existence. At the present moment we are
concerned only with the the Old Academy, and have to speak particularly of Speusippus,
Xenocrates, Heraclides of Pontus, Polemo,
Crates, Philip of
Opus, and Crantor.
Speusippus, Plato's nephew and successor at the head of the
Academy (347-339 B.C.), discarded the theory of Ideas, and posited many principles
instead of one, reducing the Idea of Plato to three distinct "causes," or
"principles," viz., the One, Reason, and the Good. He adopted the Pythagorean
theory of numbers, separating, however, numbers from things.
He slighted physics; and in ethics advanced the theory that the highest good,
or happiness, is virtue plus certain external goods needed to make life
agreeable, in other words, is "life according to nature".
Xenocrates of Chalcedon, the successor of Speusippus at the
head of the Academy, and the most distinguished member of the Old Academy,
modified the Theory of Ideas, identifying Ideas with mathematical entities.
Following Plato, he held all things to be derived from Unity and Duality. He
distinguished three media of knowledge and three corresponding classes of
existence: thought (which affords pure knowledge), perception (which gives
knowledge, though not pure), and opinion (in which truth and knowledge are mixed
in equal proportions); intelligible objects (beyond
the heavens), sensible objects (within the heavens), and objects intermediate
between these (the heavens themselves). The soul, which like all things else
springs from the two primary causes, Unity and Duality, is a self-moved number; souls differ by virtue of the difference in the manner in which Unity and
Duality unite in forming them. The soul is a spiritual essence, may exist apart
from the body, and is, in its irrational as well as its rational part, immortal.
The world is a system of graduated existences, is permeated by soul, is ruled by
gods and dæmons, and is eternal. The five elements,
ether, fire, air, water,
earth, originated from atoms. Goods are goods of the soul, of the body, and of
the outer life. Virtue is the highest good. Happiness is virtue, or the proper
development of natural faculties, plus the external goods conducing to it.
Wisdom and science are related to prudence as the theoretical to the
Other Members of the Old Academy
Pontus, who is said to have been "entrusted with the direction of the Academy
during Plato's last journey to Sicily," Polemo, who succeeded Xenocrates as head
of the Academy, Crates, successor to Polemo, Philip of Opus, editor of Plato's
Laws and supposed author of Epinomis, a supplement to the Laws, and
"the earliest expounder of Platonic writings," deserve mention. Heraclides
followed Plato in ethics, and the Pythagoreans in cosmology, in general, but
assumed as material principles atomic bodies having the power to affect each
other not mechanically but by a kind of affinity, and affirmed the soul to be an
ethereal essence. Polemo is said to have devoted himself exclusively to ethics,
particularly discountenancing dialectical speculation.