Hellenistic astrology

This system later spread either directly or indirectly through the Babylonians to other areas such as China[citation needed] and Greece where it merged with preexisting indigenous forms of astrology.

This system is labeled as "horoscopic astrology" because, unlike the previous traditions, it employed the use of the ascendant, otherwise known as the horoskopos ("hour marker") in Greek, and the twelve celestial houses which are derived from it.

The focus on the natal chart of the individual, as derived from the position of the planets and stars at the time of birth, represents the most significant contribution and shift of emphasis that was made during the Hellenistic tradition of astrology.

Hermes is said to have written several major texts which formed the basis of the art or its evolution from the system of astrology that was inherited from the Babylonians and the Egyptians.

This system of horoscopic astrology was then passed to another mythical figure named Asclepius to whom some of the Hermetic writings are addressed.

Texts from the 2nd century BCE list predictions relating to the positions of planets in zodiac signs at the time of the rising of certain decans, particularly Sothis.

According to Firmicus Maternus (4th century), the system of horoscopic astrology was given early on to an Egyptian pharaoh named Nechepso and his priest Petosiris.

By the 1st century BCE two varieties of astrology were in existence, one that required the reading of horoscopes in order to establish precise details about the past, present and future, the other being theurgic, meaning literally 'god-work', and emphasised the soul's ascent to the stars.

While they were not mutually exclusive, the former sought information about the life, while the latter was concerned with personal transformation, where astrology served as a form of dialogue with the divine.

Among the Greeks and Romans, Babylonia or Chaldea was so identified with astrology that "Chaldaean wisdom" became the synonym of divination through the planets and stars.

One of the more famous examples of Roman literature concerning astrology is the poem Astronomica, written in the first century CE by Marcus Manilius.