Ptolemy - ( Image compiled by Dr. Blog )

Claudius Ptolemaeus, or Ptolemy was an astronomer, mathemetician and geographer in the second century A.D. He codified the Greek geocentric view of the universe, and rationalized the apparent retrograde motion of the planets using epicycles. The Ptolemaic system remained the accepted wisdom until the Polish scholar Copernicus proposed a heliocentric view in 1543.

Ptolemy worked from the data of past astrologers to map over one thousand stars. He compiled a list of 48 constellations, and, for the most part, described the longitude and latitude lines of the earth. He was a believer that the earth was the center of the universe and worked to advance this theory. His effort in this area was in his thirteen volume work called the Almagest.

The Ptolemaic system is explained why some planets seemed to move backwards for periods of time in their orbit around earth. He theorized that each planet also revolved in a smaller circle as well as a larger one. This was called the “epicycle.” This theory would survive for 1400 years, until it was finally accepted that the earth was itself another planet in orbit around the sun.

The first book defined Ptolemy’s reasoning for practicing astrology as well as astronomy, for by this time, there were many who opposed astrology. He said that it should not be abandoned merely because there are a few people who abuse it. This book also deals with the various alignments of planets, the moon, and the sun. Ptolemy describes in detail which positions are favorable and which are not. He also explained the signs, when they begin, and why they begin there.

The second book of the Tetrabiblos describes astrology as it relates to countries. Ptolemy makes the point that astrological events of countries and race supersede those of the individual. He details which planets rule over which country, and makes the distinction between human signs and animal signs. He notes that human signs cause things to happen to humans and animal signs affect animals. Finally, Ptolemy explains how the planets affect earth. For example, Saturn was thought to cause cold, floods, poverty, and death. Mars caused war and drought. Comets and shooting stars were thought to also affect the weather.

The third book dealt with the individual. The Tetrabiblos examined conception and birth, saying that it was better to work with the conception date and that this date should be known by observation. Several key factors were involved with this aspect of astrology. The sign that was rising at the time of conception, the moon’s phase, and the movements of the planets were all taken into consideration. The father’s influence was shown through the sun and Saturn, while the mother’s was shown through the moon and Venus.

Finally, the forth book of the Tetrabiblos handled matters of occupation, marriage, children, travel, and ‘houses’ of the zodiac. The particular angles of various planets were used to calculate these things.

The Tetrabiblos compiled almost all of the astrological works up to that point. Only very few modifications have been made since then, and most of what we know as astrology comes from this work. Critics claim that it is “tedious and dry” to read, and that there are some contradictions in Ptolemy’s ideas.

Furthermore, he did not take into account the precession of the equinoxes. He undoubtedly knew about this phenomenon, an overlapping between signs and constellations that gets larger over time (about 5 degrees per three hundred years), but why he did not examine or explain this is a mystery and one of the biggest flaws of his work.

There were also problems with his correlation between astrology and the seasons. His belief that the conception time was preferable to birth time is a misguided one, as conception time for an individual is actually rather difficult to calculate. There were other errors in his work, mostly dealing with beliefs of the time and misinformation about astronomy; however, for the most part, the Tetrabiblos has proved invaluable to this day.

Ptolemy may never have actually practiced astrology, as there has not been a single horoscope found that was created by him. Some say that his writing almost reflects an embarrassment about astrology, and suggest that perhaps he might not have been a scholar of the art, but more a reporter of it.

Probably the most disturbing accusation against Ptolemy is that his figures were intentionally skewed and doctored to fit his hypotheses. A study of Ptolemy’s figures was done in 1977, and the findings were that most of his data was fraudulent. For more on this subject, one should refer to the book by R. Newton, The Crime of Claudius Ptolemy. It is hard to hold this against Ptolemy; he was, of course, working in ancient times. However, had he used correct numbers in his work, it might not have taken future scholars 1400 more years to correct wrong ideas concerning the universe.

In his defense, he was living during a time when ‘politically incorrect’ beliefs could be grounds for punishment. It actually may not have been safe for him to expose the truth; instead he may have been forced to make his numbers fit into incorrect theories. He knew enough about the truth...the precession of the equinoxes and the theories that postulated that the earth, in fact, revolved around the sun. Apparently, fear for his own life is the reason why he did not act on his knowledge.

After Ptolemy, many astrologers followed. Some notable Egyptians in the field were Paul of Alexandria, Hephaestion of Thebes, and Palchus, though little other than their names are known about these people. Ptolemy’s work was continued and commented on by the Alexandrian mathematician Pappus, the mathematician/astronomer Theon of Alexandria, and the Greek mathematician Proclus, who wrote a paraphrase of Ptolemy’s Tetrabiblos.