Astrology is a technically complex discipline, and the exposition in the foregoing chapter may have seemed baffling to the uninitiated. As one way of showing how it actually worked, I am going to take an individual birth chart and illustrate how two ancient astrologers would have interpreted it, according to the generalised instructions given in their works. They are quite different sources, in that they are separated by several centuries, and that one was written in Greek and the other in Latin. However, they are remarkably similar, illustrating the tenacity of astrological tradition. The reason that they are ideal for such an experiment is that they present themselves as simple handbooks, and offer precise predictions corresponding to particular configurations.
The first astrological work I use is the Mathesis, the Greek word meaning learning, which had come to connote astrological knowledge in particular. It was written by Firmicus Maternus, a Roman senator from Sicily who had been a lawyer, between 334 and 357 CE. He is thus a member of the Roman elite, and the work was dedicated to a patron high up in the imperial civil service, who is known to us from other evidence. The second work is the Pentateuch, or ‘work in five books’ by Dorotheus of Sidon, dated on the basis of the horoscopes to the mid-first century CE. This was in fact one of Firmicus’ sources. Though Dorotheus’ importance had long been known, only fragments of his original text were available until 1976. In that year David Pingree published the Arabic translation, which was based on a third-century Pahlavi translation of the Greek. This has had some obvious interpolations, two horoscopes from the third and fourth centuries CE, a couple of additions from Vettius Valens