Book review: The Arabic Parts in Astrology – A Lost Key to Prediction


Robert Zoller is an astrologer specialized on predictive astrology with studies on Latin and history (Medieval and Renaissance periods). He wrote The Arabic Parts in Astrology – A Lost Key to Prediction in 1980 and revised it in 1989.

Part 1 – Background

In Chapter 1. How the parts were lost the author presents a brief history of the astrological charts. Interesting, the origin of the parts is not at the Arabs, but, far more ancient, from the time of the Babylonians. Still, it is true that the Arabs invented more and more parts and used them extensively. In Europe the Renaissance was the period when the parts lost their importance and, even faster than astrology, began to decay.

Chapter 2. The metaphysical basis of the parts is a real lesson of numerology blended with philosophical ideas. In the first part the author emphasize on the idea that the man is a Microcosm and present some quotas from Henry Cornelius Agripa, Giordano Bruno, Hermes Trismegistus and Pico della Mirandola to sustain his arguments. I think the main idea is true, but not very well explained and presented in a rather unclear manner. Robert Zoller should have been invested more energy and efforts to present such an important and beautiful idea. Then, begins the “numerology course” and are presented the first ten numbers with their meanings and the numerical basis for the planets exaltations.

Part 2 – The doctrine of the parts

Chapter 3. How to use the Parts means a few pages with several simple advices for calculating and analyzing the astrological parts.

Chapter 4. Bonatti’s treatise on the parts is a translation made by Robert Zoller to a portion of Bonatti’s book Liber Astronomiae. Has 50 pages and is divided in 9 sections. Are presented the astrological parts of the planets, the parts for houses and even some parts which will help you to judge the cheapness of some vegetables in a certain period. Hmm… If those last parts would work some astrologers would made a lot of money at the stock exchange! But is not the case!

Part 3 – Practical Illustrations

In Chapter 6 Natal Figures the author tries to prove by practical examples that the parts are working. He analyzes the part of religion and honesty of women on 4 charts, the part of fortune on 1 chart, the part of the Sun on 2 charts, the part of the Hyleg on 2 charts and the part of the eight house on 2 charts. Of course that by those examples, he shows the efficiency of the astrological parts. But, the question is: do those parts really work on every chart?

I made an exercise and tested the Part of Honesty of women (distance from Moon to Venus projected from the Ascendant) on 3 examples. Zoller quotes Bonatti:

“if this part is in a fixed sign or in the aspect of any of the lords of the dignities of the sign in which it is placed or any benefic, the women will be honest and religious even if she may be longing for coitus. But if the malefics aspect it without reception and it is in a mobile (cardinal) sign, the women will be excessive in her desire for coitus, giving herself to men… for a cheap price and she will be in every way a fornicatrix”

So, in a chart of a prostitute the Part of Honesty should met the following conditions: be placed in a cardinal sign, with a malefic planet aspecting without reception, with no aspect from a benefic planet or from the planets with dignities in her sign. Very simple!

I randomly took 3 charts of prostitutes from Astro-Databank (Rodden Rating A):

First example is Prostitute 7995, born on 30 June 1937 at 00:12 (= 12:12 AM ) in Toronto, Canada (43n39, 79w23).

I found the Part of Honesty at 16 degrees in Taurus, in a fixed sign, in conjunction with Venus (ruler) so in reception and aspect with benefic. None of the conditions mentioned by Bonatti for prostitution are accomplished. Result: the Part of Honesty is not relevant.

Second example is Prostitute 9212, born on 23 September 1942 at 21:30 (= 9:30 PM), in Lima OH, USA (40n44, 84w06).

I found Part of Honesty at 11 degree in Scorpio, in a fixed sign, in sextile with Venus (a benefic), with no aspect from a malefic planet. None of the conditions mentioned by Bonatti for prostitution are accomplished. Result: the Part of Honesty is not relevant.

Third example is Prostitute 9448, born on 29 July 1943 at 07:00 (= 07:00 AM ), in Houston TX, USA (29n45, 95w21).

I found Part of Honesty at 20 degree in Libra, in a cardinal sign, in trine with Saturn (reception by the ruler), in an aspect with a malefic (Saturn) but with reception. Only one condition mentioned by Bonatti is met. Result: the Part of Honesty is not relevant.

You can easily see that the results are not good, so my scepticism still remains.

In the last chapters the author advices us how to use the parts on sinastry charts, horary figures, mundane figures and commodities variation.


Conclusion.The book treats a delicate and controversial subject. A technique, easy to calculate and apply, which is not generally used nowadays because astrologers don’t understand it or don’t believe in her reliability. This book, written in 1980, tries to cover this lack of confidence with some metaphysical explanations, a translation from Bonatti’s treatise on the astrological parts and a few examples.

It seems a simple construction. The central part is the translation from Bonatti preceded by theory and followed by the practical examples. But, when you read it, the situation becomes more complicated. Especially in the first part many ideas and theories are not linked together, seems to be taken from different books and quickly compiled. The author didn’t spent enough time to revise the text, to give him some fluidity and clearance. Or, maybe he didn’t succeed to express well enough in words what he wanted to say. Maybe he hasn’t the ability, the talent to write a book. Anyway, taking in account the subject, which is not very popular, few people will have the patience to read the whole book.

My opinion is that The Arabic Parts in Astrology – A Lost Key to Prediction is neither a bad book, nor a good one. Is a mediocre one. A book where you’ll find useful information and ideas together with the formulas needed to compute the entire series of astrological parts. A book which can’t be the real guide expected to enlighten your path through the mysterious world of the Arabic parts. My evaluation is 7,1.