The most essential principle of astrology was that of fatalism. As the poet says:[44]
_"Fata regunt orbem, certa stant omnia lege."_
The Chaldeans were the first to conceive the idea of an inflexible necessity ruling the universe, instead of gods acting in the world according to their passions, like men in society. They noticed that an immutable law regulated the movements of the celestial bodies, and, in the first enthusiasm of their discovery they extended its effects to all moral and social phenomena. The postulates of astrology imply an absolute determinism. Tyche, or deified fortune, became the irresistible mistress of mortals and immortals alike, and was even worshiped exclusively by some under the empire. Our deliberate will never plays more than a very limited part in our happiness and success, but, among the pronunciamentos and in the anarchy of the third century, blind chance seemed to play with the life of every one according to its fancy, and it can easily be understood that the ephemeral rulers of that period, like the masses, saw in chance the sovereign disposer of their fates.[45]
The power of this fatalist conception during antiquity may be measured by its long persistence, at least in the Orient, where it originated. Starting from Babylonia,[46] it spread over the entire Hellenic world, as early as the Alexandrian period, and towards the end of paganism a considerable part of the efforts of the Christian apologists was directed against it.[47] But it was destined to outlast all attacks, and to impose itself even on Islam.[48] In Latin Europe, in spite of the anathemas of the church, the belief remained confusedly { 180} alive all through the Middle Ages that on this earth everything happens somewhat
"Per ovra delle rote magne, Che drizzan ciascun seme ad alcun fine Secondo che le stella son campagne."[49]
The weapons used by the ecclesiastic writers in contending against this sidereal fatalism were taken from the arsenal of the old Greek dialectics. In general, they were those that all defenders of free will had used for centuries: determinism destroys responsibility; rewards and punishments are absurd if man acts under a necessity that compels him, if he is born a hero or a criminal. We shall not dwell on these metaphysical discussions,[50] but there is one argument that is more closely connected with our subject, and therefore should be mentioned. If we live under an immutable fate, no supplication can change its decisions; religion is unavailing, it is useless to ask the oracles to reveal the secrets of a future which nothing can change, and prayers, to use one of Seneca's expressions, are nothing but "the solace of diseased minds."[51]