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Morin's Astrology
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The Astrology of Jean Baptiste Morin, by Thomas Callanan

"… I am excessively inclined to consider myself superior to others on account of my intellectual endowments and scientific attainments, and it is very difficult for me to struggle against this tendency, except when the realization of my sins troubles me, and I see myself a vile man and worthy of contempt. Because of all this my name has become famous throughout the world."
Morin de Villefranche

Who is this man so obviously proud of his humility? These are the words of the author of Astrologiae Gallicae (French Astrology), a 26 volume work of natural philosophy and astrology: Jean Baptiste Morin de Villefranche (1583 - 1656), the greatest and most famous of all French astrologers. This is a man who once told his friend, Rene Descartes, that he knew as soon as they met, that Descartes' philosophy was flawed. Less well known today by English speaking astrologers than others of his era, Morin's ideas provide the basic philosophy for many contemporary French and Spanish practitioners. Unfortunately for him, the influence finally achieved by his monumental work that took over 30 years to complete came long after his death. Written in the scholarly style of Latin expected in his day, it would be published posthumously in 1661, and lie virtually untouched for centuries.

Morin's timing couldn't have been worse. Astrology was on the defensive in the mid 17th century in Europe. The scientific craze was beginning; the actual order of the cosmos was being debated, and would be settled in favor of Copernicus. This was no time to produce a giant volume of natural philosophy and astrology and expect great recognition.

The recognition would begin in earnest in the late 19th century when the 21st volume of the work would be translated into Spanish, then into German in the early 20th century, and finally some volumes trickling into English during the later 20th century. The first 8 books barely mention astrology at all. They lay the foundation for astrological thinking and discuss in depth topics such as proof of the existence of God, opinions of the Church Fathers of astrology, fate and free will, and the ordering of the cosmos. The practice of astrology is discussed in later volumes: volume 18 dealing with, among other things the strengths and weaknesses of the planets, volume 21 serving as an overall view to his method of horoscope interpretation. Volume 22 gives us his theories of the interpretation of directions. Volume 23 continues with his methods for prediction discussing "revolutions" or solar and lunar returns. From these four books any astrologer can comprehend Morin's system and run with it should he so desire.

Morin was born on February 22, 1583, 8:28:40 Universal Time (rectified), at Villefranche, France. [View chart]. It seems he was born into a reasonably affluent family. He was well educated and had a degree in medicine (1613), and probably philosophy. He developed a system of measurement of longitude based on the position of the Moon for which he felt he was deprived of proper credit, and monetary reward (later given to him). The system, although theoretically sound, required precision instruments that did not exist in his day. The Bishop of Boulogne underwrote a trip for him to Germany, Hungary, and Transylvania during the years 1613 - 1621 where Morin studied metals, and made use of his astrological skills. From 1621 to 1629 he was the personal physician to the Duke of Luxomburg, and from 1630 until his death in 1656 he earned a living from astrology and as a professor of mathematics at the College Royal, where he attacked Galileo before and after his trial. To his dying day, he refused to believe the Earth was anything other than stationary.

Morin's Astrology

Morin believed disciplined logic could produce an astrological system that would provide concrete results when rigorously applied. The basis of his astrology is nature. Astrological technique that did not use the natural movements of the planets, either by diurnal or zodiacal motion, could not be correct. He rejected the association with mythology as the source of the meanings of the planets. The source of all power was the 'primum mobile' (also translated as primum caelum in one of the volume 21 translations. See note below). This is the farthest crystalline sphere to which the signs of the zodiac are attached and fixed. The signs derive their influence from the unchanging primum mobile. Think of light passing through a prism and becoming 12 "colors" or influences. The planets derive their meanings from the signs they rule. These meanings are fixed and unchanging, but are joined with the signs as the planets pass through them. These combined influences are sent to earth and applied universally to everyone and everything, but the influence is modified by the influence of the mundane houses and thereby tailored to the individual or event.

By today's standards he was a traditional astrologer. In his day, he was a reformer. He challenged the astrology of Ptolemy and others. He made changes to those things that offended his reason. Volume 21 contains more than a few snipes at Ptolemy and other revered astrologers, such as Bonatti and Cardan. Morin rejects the use of the terms, faces, and Arabic parts (except fortuna) as "fictions" of the Arabs and Chaldeans. He rejects the use of the equal house system and Campanus system, preferring Regiomontanus, on the grounds that his own chart would be incomprehensible given his life experiences, using other systems whereas it makes perfect sense using Regiomontanus.

Morin's changes are often quite logical, if lacking in precedent. For example, after dropping the terms and faces he changes the triplicity rulerships, an action that deserves some explanation. Each one of the triplicities has three rulers (we will excuse Ptolemy and Lilly from this discussion). Dorotheus of Sidon gave us the triplicity rulers most commonly used. There is a day ruler, a night ruler, and a participating ruler. If the Sun is above the horizon, the day rulers of the triplicity have the most influence over planets in that triplicity. If the Sun is below the horizon, the night ruler has priority, and the participating ruler some constant effect. effect.

The Dorothean rulers are:

Day Night Participating
Fire Sun Jupiter Saturn
Earth Venus Moon Mars
Air Saturn Mercury Jupiter
Water Venus Mars Moon

A quick study of this table shows that it is based on sect. The Sun, Jupiter and Saturn are diurnal planets. All the fire signs are diurnal. The planets that rule the earth triplicity are nocturnal planets. The earth signs are all nocturnal, and so on.

Morin reasoned that the assignment of triplicity rulers should be based on sign and exaltation rulership, since in his view, the planets derived their meanings from the signs they ruled. The Sun has rulership and exaltation in fire signs (Leo and Aries). So it is logical the Sun would influence those signs in a day chart more than any other planet. Mars is the ruler of a cardinal fire sign, and would make an important impact in fire, so he is assigned the night rulership. Jupiter has rulership in the remaining fire sign Sagittarius, so he is the participating ruler.

This system produces the following rulerships:

Day Night Participating
Fire Sun Mars Jupiter
Earth Mercury Saturn Venus
Air Saturn Venus Mercury
Water Jupiter Moon Mars

While it is unarguable Morin has produced a system of great beauty and elegance, the question remains: does it work? Triplicity is not the strongest of essential dignities and comparison would make for a difficult research project, and possibly it would not produce a definitive result. What is indisputable is that Morin is using essential dignity, domicile and exaltation rulership, to determine an essential dignity. Dorotheus system is based on sect, and the connection to essential dignity is tenuous at best.

Did he produce anything useful to a modern astrologer? Yes, indeed. It would be a mistake to dismiss Morin as an egocentric iconoclast who produced little of lasting significance. Robert Zoller currently teaches Morin's system of interpreting planets in houses (position is more powerful than rulership on the grounds of immediacy. A planet contacted by direction or transit will manifest in the house that holds it before and more obviously than it will manifest in the house ruled by the planet), and Zoller considers medieval astrology the high watermark of the craft; Morin is not medieval. Morin developed an orderly system of looking at the planets and determining which of the many meanings are appropriate in a particular chart. When is the Moon the mother, and when is the Moon the wife, or daughter? Morin provides us with guidelines. Is a planet more influential in the mundane house it occupies or the mundane house it rules? Morin answers that it is the occupied house that is influenced more. Does the exaltation ruler influence the house under consideration? Morin tells us that it does, and greatly.

There are innovations as well. Morin looks at the opposite house to give us understanding of the house under consideration. Can we really learn enough about our finances without looking to the house of the finances of others? Can we learn about ourselves without knowing our partners?

His pamphlet, "The Cabal of the Twelve Houses Astrological" only 17 pages in length is of profound significance and needs to be on the shelf of every astrologer, traditional or contemporary. He determines the meanings of the houses from the "grand trine (he uses the term "triplicity") of houses" that begins with each angle. The Ascendant is trine to the 5th and 9th. A man lives (first house) for his posterity (5th house) and his God (9th). The grand trine from the 10th involves his honors or position in society that he calls the house of action, which produces things that are immaterial, and from which comes those things that are material and animated, servants, working animals (6th), and those things that are material and inanimate: gold silver, and other goods (2nd).

The third is the grand trine of conjunction beginning at the 7th house of matrimony, the conjunction of Blood that is represented by relatives in the third house, and the conjunction of the 11th -- the conjunction with friends.

The final grand trine comes from the dark angle or the 4th house -- the lowest point in heaven. This is attributed to old age, affliction, and passion, from which flow the afflictions of the 12th house: treachery, injuries, and enemies; and death brought by the 8th house.

Morin had a gift for tying things together in a perfectly rational manner. Today some of his growing number of adherents have incorporated the outer planets into his system. Many astrologers benefit from his thinking without knowing it, since even their teachers are unaware of his influence.

In the middle of October 1656, Morin is told by a chiromancer that the following month will be fatal to him. He is in altogether good health. He smiles. He's seen it in his chart. A little more than a week later he is taken with fever, and urges his doctors not to trouble themselves too much. His end is inevitable. At 2:00 AM on November 6, in Paris, Jean Baptiste Morin passes leaving many to wonder what might have been had he been born at a time when his greatest gifts would have received greater appreciation.


Jean Baptiste Morin de Villefranche

 View Morin's Natal Chart

 Read: The Cabal of the 12 Houses Astrological

Note on tranlsations:

  There are two English translations of volume 21 of Astrologica Gallica that I am aware of. Richard S. Baldwin translated volume 21 in 1974. It is slim (109 pages), paperbound, and inexpensive. It is translated from the original Latin. New York City astrologer Zoltan Mason commissioned Lucy Little to do a translation of the same volume also in 1974. The little translation is from a French translation of the Latin. Mason published it. The book is a handsome hardbound edition that contains, in addition to the text, further explanations of Morin's approach, and the Ashmand translation of the Centiloquy attributed to Ptolemy, but today no one believes it was actually written by Ptolemy. This book is more expensive than Baldwin's. I found Baldwin's a little easier to follow, but that may be a personal idiosyncrasy. Both volumes are available from the AFA.
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Bibliography & Links:

  1. Astrosynthesis: The Rational System of Horoscope Interpretation according to Morin de Villefranche. Translated by Lucy Little. Zoltan Mason Emerald Books, New York, NY 1974. [Purchase details]

2. The Morinus System of Horoscope Interpretation translated by Richard S. Baldwin. The American Federation of Astrologers, Washington, DC 1974.

3. Astroloica Gallica Book 22 Directions Translation by James Herschel Holden, American Federation of Astrologers, Tempe AZ, 1994.

4. The Cabal of the Twelve Houses Astrological by Jean Baptiste Morin, translated by George Wharton, 1659. Republished in Facsimilie format by Ascella, London, England. Reproduced online at

5. Biography of Morin de Villefranche(article) translated by James Holden, April 22, 1986. This article is a translation of the German text on pp. 272-5 of Wilhelm Knappich’s Qeschichte der Astrologie [“History of Astrolgy”] (Frankfurt am Main, 1967).

6. The Life of Morin de Villefranche (article) by Dr. Carlos Raitzen translated by Anthony LaBruzza, 2001

7. Morin, Jean Baptiste Curriculum Vitae; compiled by: Richard S. Westfall, Department of History and Philosophy of Science, Indiana University.

8. Jean Baptiste Morin The School of Mathematics and Statistics; University of St. Andrews, Scotland

These guys got it right. The errors are all mine.

Addendum to updated version: It recently came to my attention that this little piece, intended to whet the appetite of astrologers, has been cited as a source in various places on the web. It was not and is not intended as a scholarly research paper. It is based on simple desktop research and my modest home library. There is a great deal more information on Morin available in French than there is in English. While I believe the facts cited above are true, I made no special effort to verify them as a scholar would and should do. If anyone spots errors in this piece, please feel free to e-mail them to me

Tom Callanan is an American perpetual student of astrology. He has a Bachelor of Arts degree in Political Science, and has completed John Frawley’s Apprenticeship. His interests are in the practice of traditional western astrology and the philosophy that supports it. He can be reached at

© Thomas Callanan, August 2003. Page updated April 25, 2008

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