hat was taking hold of the world, and from the time of its
propagation astrology found opponents among the philosophers. The most
subtle of these adversaries was the probabilist Carneades, in the second
century before our era. The topical arguments which he advanced, were taken
up, reproduced, and developed in a thousand ways by later polemicists. For
instance, Were all the men that perish together in a battle, born at the
same moment, because they had the same fate? Or, on the other hand, do we
not observe that twins, born at the same time, have the most unlike
characters and the most different fortunes?

But dialectics are an accomplishment in which the Greeks ever excelled, and
the defenders of astrology found a reply to every objection. They
endeavored especially to establish firmly the truths of observation, upon
which rested the entire learned structure of their art: the influence of
the stars over the phenomena of nature and the characters of individuals.
Can it be {167} denied, they said, that the sun causes vegetation to appear
and to perish, and that it puts animals _en rut_ or plunges them into
lethargic sleep? Does not the movement of the tide depend on the course of
the moon? Is not the rising of certain constellations accompanied every
year by storms? And are not the physical and moral qualities of the
different races manifestly determined by the climate in which they live?
The action of the sky on the earth is undeniable, and, the sidereal
influences once admitted, all previsions based on them are legitimate. As
soon as the first principle is admitted, all corollaries are logically
derived from it.

This way of reasoning was universally considered irrefutable. Before the
advent of Christianity, which especially opposed it because of its
idolatrous character, astrology had scarcely any adversaries except those
who denied the possibility of science altogether, namely, the
neo-Academicians, who held that man could not attain certainty, and such
radical sceptics as Sextus Empiricus. Upheld by the Stoics, however, who
with very few exceptions were in favor of astrology, it can be maintained
that it emerged triumphant from the first assaults directed against it. The
only result of the objections raised to it was to modify some of its
theories. Later, the general weakening of the spirit of criticism assured
astrology an almost uncontested domination. Its adversaries did not renew
their polemics; they limited the