Ptolemy was the author of several scientific treatises, three of which have been of continuing importance to later Islamic and European science. One is the astronomical treatise that is now known as the Almagest (in Greek Î— Î¼ÎµÎ³Î¬Î»Î· Î£ÏÎ½Ï„Î±Î¾Î¹Ï‚, "The Great Treatise"). The second is the Geography, which is a thorough discussion of the geographic knowledge of the Greco-Roman world. The third is his astrological treatise known as the Tetrabiblos in which he attempted a lengthy theoretical, philosophical and technical reconceptualization of Horoscopic astrology in order to align it with the prevailing Aristotelian cosmology of his day.
In the Tetrabiblos Ptolemy explicitly argues that astrology works due to some sort of causal mechanism where the planets cause change in the sublunar world by transmitting motion to the four elements which then carry their effluence to the world below.
Note 1: For example, see James Holden's introduction to his translation of Abu Ali Al-Khayyat's The Judgments of Nativities, pgs. 11-12. Also see Holdens section on Ptolemy in his book A History of Horoscopic Astrology, specifically pages 48-49 where he makes the statement that "Ptolemy cites no astrological authorities by name, he gives no example horoscopes, and he certainly was not a practicing astrologer."
- Wikipedia's article on Ptolemy - retrieved 12/3/2005 under the GNU Free Documentation License
- James Holden, A History of Horoscopic Astrology, American Federation of Astrologers, Tempe, AZ, 1996. ISBN 0-86690-463-8
- James Holden, Abu Ali Al-Khayyat: The Judgement of Nativities, American Federation of Astrologers, Tempe, AZ, 1988. ISBN 0-86690-339-9
Further readings =
- J. M. Ashmand (transl.)Tetrabiblos. London: Davis and Dickson, 1822.