Sphaerus
(
Σφαῖρος). A Stoic philosopher, who studied first under
Zeno of Citium, and afterwards under Cleanthes. He lived at Alexandria during the reigns of
the first two Ptolemies. He also taught at Lacedaemon, and was believed to have had
considerable influence in moulding the character of Cleomenes. He was in repute among the
Stoics for the accuracy of his definitions. He was the author of several works, all of which
are lost.