Claudius Ptolemy

Claudius Ptolemy was a Roman mathematician, astronomer, geographer and astrologer.

He was born about 90AD – lived in Egypt – and worked at the Library in Alexandria.

There he wrote Tetrabiblos – a treatise on the ancient principles of horoscopic astrology – and the book’s importance and astrological significance is second to none.


In Tetrabiblos Ptolemy presents the rules for drawing up a birth chart, identifies the influence of the fixed stars, gives rules for determining the length of life and indicates the sign rulership of various nations.

He summarized, and logically sequenced, the astrology of the ancients. His achievement was to rationalize astrology and Tetrabiblos laid the basis for western astrological tradition. To quote Elbert Benjamine:

‘Ptolemy’s books are the foundation upon which modern astrology rests; for nearly all his rules for erecting and judging a birth chart have been found correct when applied at the present time.

A few of the rules for calculating directions were not made entirely plain by Ptolemy, who leaned strongly to the Egyptian Method, which was further developed by Placidus de Titus, a monk of later times.

However the fact remains...that the description of the influence upon life by each planet and zodiacal sign, his rules for erecting and judging charts, his one hundred aphorisms, methods for judging mundane events etc…, can be completely relied upon to this day.

From this completeness and astrological knowledge we may safely infer that Ptolemy had access to information not generally accessible even in his day.

His Celestial Sphere and astrological knowledge was not that of the populace, it was that of Initiation and we have Ptolemy’s own statement that it was for the purpose of handing the wisdom of the ancients down to posterity.’

Fact check:Tetrabiblos 

But all was not astrological fact.

The fixed stars do not exert an astrological influence.

Ptolemy gave the rulership of the father to the Sun and Saturn and the mother to the Moon and Venus and modern statistical research has confirmed that house 4 in your birth chart rules your father and house 10 rules your mother.

He also emphasized astrology’s predictive power, but cautioned against trying to be too precise.

During the Age of Pisces some astrologers ignored his advice and argued that greater precision was possible.

All it required was technical know-how – the diligent practice of astrological principles – and a little bit of extrasensory perception.

According to Ptolemy

Ptolemy wrote: ‘The science of astrology demands the greatest study and a constant attention to a multitude of different points.’

These variables included race, country and upbringing.

He claimed: ‘Mistakes arise, not from any deficiency or want of power in the science itself, but from the incompetency of unqualified persons who pretense to exercise it.

The reproach brought upon the science wholly unmerited; for it would be equally just to condemn all other branches of philosophy because each numbers among its professors some mischievous pretenders.’

Ptolemy summed up his earthly life by paying tribute to God’s handiwork:

 ‘I know that I am mortal, the creature of one day; but when I explore the winding courses of the stars my feet no longer touch the Earth: I am standing near Zeus himself, drinking my fill of Ambrosia, the food of the gods.’

Author: DW Sutton

Astrology for Aquarius – sharing our knowledge

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