involves a particular
theory of the solar system, that which we now know as the Ptolemaic. It
is not the order of the Babylonians, for they arranged them, Moon, Sun,
Mercury, Venus, Saturn, Jupiter, Mars.

There are further considerations which show that the Babylonians could
not have given these planetary names to the days of the week. The order
of the names implies that a twenty-four hour day was used, but the
Babylonian hours were twice the length of those which we use; hence
there were only twelve of them. Further, the Babylonian week was not a
true week running on continuously; it was tied to the month, and hence
did not lend itself to such a notation.

But the order adopted for the planets is that current amongst the Greek
astronomers of Alexandria, who did use a twenty-four hour day. Hence it
was certainly later than 300 B.C. But the Greeks and Egyptians alike
used a week of ten days, not of seven. How then did the planetary names
come to be assigned to the seven-day week?

It was a consequence of the power which the Jews possessed of impressing
their religious ideas, and particularly their observance of the sabbath
day, upon their conquerors. They did so with the Romans. We find such
writers as Cicero, Horace, Juvenal and others remarking upon the
sabbath, and, indeed, in the early days of the Empire there was a
considerable observance of it. Much more, then, must the Alexandrian
Greeks have been aware of the Jewish sabbath,--which involved the Jewish
week,--at a time when the Jews of that city were both numerous and
powerful, having equal rights with the Greek inhabitants, and when the
Ptolemies were sanctioning the erection of a Jewish temple in their
dominions, and the translation of the Jewish Scriptures into Greek. It
was after the Alexandrian Greeks had thus learned of the Jewish week
that they assigned the planets to the seven days of that week, since it
suited their astrological purposes better than the Egyptian week of ten
days. That allotment could not possibly have brought either week or
sabbath into existence. Both had been recognized many centuries earlier.
It was foisted upon that which had already a venerable antiquity. As
Professor Schiaparelli well remarks, "we are indebted for these names to
mathematical astrology, the false science which came to be formed after
the time of Alexander the Great from the strange intermarriage between
Chaldean and Egyptian superstitions and the mathematical astr