The sky, whose unfathomable depth had not yet been perceived, was peopled with heroes and monsters of contrary passions, and the struggle above had an immediate echo upon earth. By what principle have such a quality and so great an influence been attributed to the stars? Is it for reasons derived from their apparent motion and known through observation or experience? Sometimes. Saturn made people {173} apathetic and irresolute, because it moved most slowly of all the planets.[28] But in most instances purely mythological reasons inspired the precepts of astrology. The seven planets were associated with certain deities, Mars, Venus, or Mercury, whose character and history are known to all. It is sufficient simply to pronounce their names to call to mind certain personalities that may be expected to act according to their natures, in every instance. It was natural for Venus to favor lovers, and for Mercury to assure the success of business transactions and dishonest deals. The same applies to the constellations, with which a number of legends are connected: "catasterism" or translation into the stars, became the natural conclusion of a great many tales. The heroes of mythology, or even those of human society, continued to live in the sky in the form of brilliant stars. There Perseus again met Andromeda, and the Centaur Chiron, who is none other than Sagittarius, was on terms of good fellowship with the Dioscuri. These constellations, then, assumed to a certain extent the good and the bad qualities of the mythical or historical beings that had been transferred upon them. For instance, the serpent, which shines near the northern pole, was the author of medical cures, because it was the animal sacred to AEsculapius.[29] The religious foundation of the rules of astrology, however, can not always be recognized. Sometimes it is entirely forgotten, and in such cases the rules assume the appearance of axioms, or of laws based upon long observation of celestial phenomena. Here we have a simple aspect of science. The process of {174} assimilation with the gods and catasterism were known in the Orient long before they were practiced in Greece.