other places (Acad. i. 10, Tusc. Quaest. v. 9), that he appeared unable to
comprehend a happiness resting merely on virtue; so that he had attributed
to virtue a rank very inferior to its deserts.

_Xenocrates_ was a native of Chalcedon, born probably B.C. 396. He was a
follower of Plato, and accompanied him to Sicily. After his death, he
betook himself, with Aristotle, to the court of Hermias, tyrant of
Ptarneus, but soon returned to Athens, and became president of the Academy
when Speusippus, through ill health, was forced to abandon that post. He
died B.C. 314.

He was not a man of great genius, but of unwearied industry and the purest
virtue and integrity. None of his works have come down to us; but, from
the notices of other writers, we are acquainted with some of his peculiar
doctrines. He stood at the head of those who, regarding the universe as
imperishable and existing from eternity, looked upon the chronic
succession in the theory of Plato as a form in which to denote the
relations of conceptual succession. He asserted that the soul was a
self-moving member,--called Unity and Duality deities, considering the
former as the first male existence, ruling in heaven, father and Jupiter;
the latter as the female, as the mother of the Gods, and the soul of the
universe, which reigns over the mutable world under heaven. He
approximated to the Pythagoreans in considering Number as the principle of
consciousness, and consequently of knowledge; supplying, however, what was
deficient in the Pythagorean theory by the definition of Plato, that it is
only in as far as number reconciles the opposition between _the same_ and
the different, and can raise itself to independent motion, that it is
soul.

In his ethics he endeavoured to render the Platonic theory more complete,
and to give it a more direct applicability to human life; admitting,
besides the good and the bad, of something which is neither good nor bad,
and some of these intermediate things, such as health, beauty, fame, good
fortune, he would not admit to be absolutely worthless and indifferent. He
maintained, however, in the most decided manner, that virtue is the only
thing valuable in itself, and that the value of everything else is
conditional, (see Cic. de Fin. iv. 18, de Leg. i. 21, Acad. i. 6, Tusc.
Quaest. v. 10-18,) that happiness ought to coincide with the consciousness
of virtue. He did not allow that mere intellectual scientific wisdom was
the only tr