known that the Greeks were indebted to the Egyptians for much of their
theology as well as science. The great truths which really underlay the
mysterious religious rites of Egypt seem to have been altogether lost
when the Greeks wove their complicated system of theology; and we read
that the Egyptian priests looked on the Greeks as children who failed to
understand the great mysteries involved in their religious rites,
disguised as they were in symbolic form. But, besides their indebtedness
to Egypt, we will find that they also owed much to Persia, and through
it again to Indian sources of knowledge.

There was constant communication between the Grecian and Persian
nations. We learn that it was not uncommon for Grecian generals to take
service under the Persian Satraps, tempted by the liberal recompence
with which their services were rewarded. About the year 356 B.C. this
system of Greeks accepting service under Persian Satraps nearly caused
the outbreak of war between Greece and Persia--Chares, a Grecian
commander, having assisted with his fleet and men, Artabanus, the Satrap
of Propontis, who was then in revolt against the Persian king. But
before this, during the great plague which desolated Athens in 430 B.C.,
and which also extended to Persia, Hippocrates was invited to go to the
Persian Court; and it is on record that Ctesias was for seventeen years
physician at the Persian Court about 400 B.C., during which period he
wrote his history of Persia, and an account of India, which Professor
Wilson, in a paper read to the Ashmolean Society of Oxford, has shown to
contain notices of the natural productions of the country, “which,
although often extravagant and absurd, are, nevertheless, founded on
truth.”

There were, too, Grecian soldiers employed as paid auxiliaries, and a
colony of Greeks who had been taken prisoners of war was founded within