6I have described the true circuit of the heavens about the earth, the arrangement of the twelve signs, also that of the northern and southern constellations, because therefrom, from the opposite course of the sun through the signs, and from the shadows of gnomons at the equinoxes, are formed the diagrams of analemmata.
2The rest which relates to astrology, and the effects produced upon human life by the twelve signs, the five planets, the sun and the moon, must be left to the discussions of the Chaldeans, whose profession it is to cast nativities, and by means of the configurations of the stars to explain the past and the future. The talent, the ingenuity, and reputation of those who come from the country of the Chaldeans, is manifest from the discoveries they have left us in writing. Berosus was the first of them. He settled in the island and state of Cos, and there established a school. Afterwards came Antipater and Achinapolus, which latter not only gave rules for predicting a man’s fate by a knowledge of the time of his birth, but even by that of the moment wherein he was conceived.
3In respect of natural philosophy Thales the Milesian, Anaxagoras of Clazomenæ, Pythagoras the Samian, Xenophanes of Colophon Democritus the Abderite, have published systems which explain the mode in which Nature is regulated, and how every effect is produced. Eudoxus, Endæmon, Callippus, Melo, Philip, Hipparchus, Aratus, and others, following in the steps of the preceding, found, by the use of instruments, the rising and setting of the stars and the changes of the seasons, and left treatises thereon for the use of posterity. Their learning will be admired by mankind, because, added to the above, they appear as if by divine inspiration to have foretold the weather at particular seasons of the year. For a knowledge of these matters reference must therefore be made to their labours and investigation.