Not my theory:
''The science of astrology was developed in, most probably, the late 2nd or early 1st century B.C., as a mean to predict, from horoscopic themata draw up for the moment of an individual's birth (or conception), the fate of that native. This form of astrology, called genethlialogy, is rooted in Aristotelean physics and Hellenistic astronomy, but also borrowed much from Mesopotamia and some elements from Egypt as well as developing many theories of its own... All of these types of astrology depend on the notion that the planets, in their eternal rotations about the earth, transmit motion (change) to the four elements and to the assemblages of elements, animate or inanimate, in the sublunar world. This theory is completely different from that of celestial omens, in which the gods, whose physical manifestations are the constellations and planets send messages concerning their intentions regarding kings and countries by means of celestial phenomena.'' - Pingree, D. E. (1997). From astral omens to astrology: from Babylon to Bīkāner