of civilized life: and he is said to have
taught that all minds are air, exactly alike, and composed of similar
particles; but that in beasts and in idiots they are hindered from
properly developing themselves by various humors and incapacities of their
bodies. He died B.C. 323, the same year that Epicurus came to Athens.

_Zeno_ was born at Citium, a city of Cyprus; but having been shipwrecked
near Cyprus, he settled in that city, where he devoted himself to severe
study for a great length of time, cultivating, it is said, the
acquaintance of the philosophers of the Megaric school, Diodorus and
Philo, and of the Academics, Xenocrates and Polemo. After he had completed
his studies, he opened a school himself in the porch, adorned with the
paintings of Polygnotus ({~GREEK CAPITAL LETTER SIGMA~}{~GREEK SMALL LETTER TAU~}{~GREEK SMALL LETTER OMICRON~}{~GREEK SMALL LETTER ALPHA WITH VARIA~} {~GREEK SMALL LETTER PI~}{~GREEK SMALL LETTER OMICRON~}{~GREEK SMALL LETTER IOTA~}{~GREEK SMALL LETTER KAPPA~}{~GREEK SMALL LETTER IOTA WITH OXIA~}{~GREEK SMALL LETTER LAMDA~}{~GREEK SMALL LETTER ETA~}), from which his followers were
called Stoics. The times of his birth and of his death are not known with
any exactness; but he is said to have reached a great age.

In speaking of the Stoic doctrines, it is not very clear how much of them
proceeded from Zeno himself, and how much from Chrysippus and other
eminent men of the school in subsequent years. In natural philosophy he
considered that there was a primary matter which was never increased or
diminished, and which was the foundation of everything which existed: and
which was brought into existence by the operative power,--that is, by the
Deity. He saw this operative power in fire and in aether as the basis of
all vital activity, (see Cic. Acad. i. 11, ii. 41; de Nat. Deor. ii. 9,
iii. 14,) and he taught that the universe comes into being when the
primary substance passing from fire through the intermediate stage of air
becomes liquefied, and then the thick portion becomes earth, the thinner
portion air, which is again rarefied till it becomes fire. This fire he
conceived to be identical with the Deity, (Cic. de Nat. Deor. ii. 22,) and
to be endowed with consciousness and foresight. At other times he defined
the Deity as that law of nature which ever accomplishes what is right, and
prevents the opposite, and identified it with unconditional necessity. The
soul of man he considered as being