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Onomancy: A Forbidden Art of the Ars Notoria, Part I

Updated: Dec 3, 2023

“Now, the seven mechanics are these: hydromancy, pyromancy, [and] nigromancy; under astrology, chiromancy, geomancy, geonogia, [and] neonegia.”

--- Ars Notoria, section 71 (my translation from Ars Notoria: The Notory Art of Solomon, Inner Traditions, 2023)

The Ars Notoria mentions “seven mechanics” which is a descriptive term used for what it idiosyncratically calls the “seven exceptives.” The seven exceptives are those arts that are “excepted”, or excluded, from the accepted forms of knowledge, such as the seven liberal arts (i.e., grammar, logic/dialectic, rhetoric, arithmetic, music, geometry, and astronomy). The seven exceptives are described as “mechanical” in the sense that they are practical arts that are both natural and require mathematical or astrological calculations. Such arts were sometimes classified under the “middle sciences”, also called the general sciences. The entire matter of how knowledge was classified in the medieval world and the Ars Notoria is explained fully in my book. What is of particular interest here are the last two otherwise unattested terms – geonogia and neonegia. I propose that these words are a corruption and/or abbreviation of Greek words that became mistransliterated into Latin for genethlialogy and onomancy, respectively. The proposed Greek word in its Romanized form is "genethlialogia" which became abbreviated as "ge[n]ethl[ia]logia" but corrupted into "geonogia". The proposed Greek word in its Romanized form is "onomalogia", that is, "onomalogy" which is not a word at all but understood as the "study of the name" (onoma- + logia, from onoma and logos), and then became abbreviated as "o[n]o[m]e[n]logia" and then corrupted into "neonegia". Now my proposition is not definitive about these words meaning “genethlialogy” and “onomancy,” but it is an educated guess based on the knowledge of medieval scribal practices of abbreviations, the fact that these arts are “sub astrologia (under astrology),” and that deductive logic and the process of elimination leads to these two arts as the best candidates for the given historical context.

Genethlialogy (Greek γενεθλιαλογία; Latin genethlialogia), is another word for natal astrology, that is, the making and interpreting of a star chart based on calculated information about a person’s birth (i.e., horoscope) in order to predict that person’s fortunes and future. Genethlialogy has been well-documented and those aspects which are understudied are covered in my book. What this blog entry focuses on is onomancy (Greek ὄνομαμᾰντείᾱ; Latin onomamanteia), that is, the divinatory practice of taking the letters of a person’s name, converting each letter into a numerical value, and then applying certain algorithms to achieve a numerical result, which is then interpreted to assess a person’s fortune. Both genethlialogy and onomancy were interlinked in the body of medieval and astrological literature.

Onomancy often used computations related to certain astrological elements, and one can think about onomancy as the forerunner to modern day numerology. The onomantic method has four parts: (1) the question; (2) the names relevant to the question; (3) the algorithm for the computation of those names; and (4) the numerical result, what it means, and how it answers the question. In the late medieval world, all onomantic computations can be categorized into three types according to the numerical result. All three types are covered extensively in my book; however, this blog entry will focus on the third type which is the numerical value of the remainder corresponding to the same number in a results table. In my book, I explore in depth the onomantic device called the Sphere of Life and Death as it relates to the figure of medicine. Here, I examine a certain results table called “The Calculus Table of the Victorious and the Vanquished.”[1] This onomantic device answers such questions as to the outcome of a person’s sickness, what events might occur while traveling abroad, and the winner of a contest between two combatants. This particular onomantic computation is best known for its appearance in the highly popular Secreta Secretorum (Secret of Secrets), a pseudo-Aristotelian treatise which claims to be a letter composed by Aristotle and addressed to his student Alexander the Great[2] on an encyclopedic range of topics, including astrology and magic.[3] The following text for the “Table of the Victorious and the Vanquished” comes from the late twelfth- or early thirteenth- century Arundel 339 manuscript held at the British Library in London, it reads:

“The most perfect, arcane, and divine rule, in which Pythagoras[4] and Ptolemy[5] labored enough with a difficult original notion, what no mortal with a thoroughgoing [understanding of the notion] now knows, having excepted the divine secret-like wisdoms of Abreo.[6] Alexander the Great had this [rule] with him in every running about of the globe, and he subjugated entire things, seeing beforehand all things, all future, prosperous, or adverse things.

"If [someone was] sick, [he foresaw] restitution, or [if someone was sick, then he foresaw that the person was] to lie in a grave [according to the rule]; in a fight of two, either two brothers, sisters, or legitimately united [siblings, he foresaw who was] about to win; as soon as you know the names, you will judge; [if] going abroad to [visit] a friend, you and others will be able to indicate, having begun [the journey], [the outcome of] a matter as good or bad, on this day at this very hour of the day.

"We write the numbers of all the letters and all the planets, as for the name or names from which you question, you will compute [what] you want, and having made the highest [number] of each [name] through a seven or through a nine division, according to the rules written below, which conquers which, you must discover the number plainly, having run down to the inferior [numbers]. If a matter of one number of a name was with a planet number, which then it rules over [him]; it will co-adapt, favoring the inquisitor, [and] it will not ever deceive. We collate the numbers of the elements immediately.

"Attend to how each planet presides over the 24 natural hours of a day. Ergo, while you want to see good or evil about to pass, since the hour, having begun the matter [and] having purchased an astrolabe, discover the hour, and consider the planet which must have dominion on this day for this hour, and the number of your or his name about which you question to accept and divide [it] through nine; similarly, [do the same for] the number of the planet, and either number will overcome the [other] number; it is efficacious here. If a planet will conquer [the number of the name, then it is] a bad [outcome]. If your name or another [person’s name] conquers, [then it is] a good [outcome]. In this way, concerning the [person’s] name and the planet, it will be a fight. Concerning those united [by familial bonds] or intimate friendships, having been finished with the aggregation of the highest [numbers], divide through seven, and you have what you want. Over nine or seven, they remain out of one or the other part so many times, and having discovered those so many times, you must regard the following inscription. For the sick and a contention, divide through 9. For the united [family members, divide] through 7.”[7]

The Table of the Victorious and Vanquished. The first column presents the two remainders from both quotients made by dividing the number of each person’s name by 9 (or 7). The second column presents the predicted victor of the outcome in question.

The Table of Letter-Number Equivalents according to Cambridge, Trinity College, R.17.1, the Eadwine Psalter, 12th century, f. 282v. The letter-number equivalents varied among the extant collection of manuscripts. Unlike Hebrew, Arabic, or Greek, the Latin alphabet does not have an established foundation in which each letter was originally assigned a number. This deficiency accounts for the diversity of letter-to-number assignments.

The Table of Number-Planet Equivalents according to Cambridge, Trinity College, R.17.1.

In other words, each person’s name is first converted into a number according to the table of letter-number equivalents. For example, the name Thomas (T = 8, H = 6, O = 8, M = 23, A = 3, S = 9) equals 57 and the name Leopold (L = 12, E = 22, O = 8, P = 13, O = 8, L = 12, D = 24) equals 99. Both numbers are divided by 9 (or 7). When divided by 9, Thomas’ quotient is 6 with a remainder of 3. When divided by 9, Leopold’s quotient is 11 with a remainder of 0. Since all remainders must fall between 1 and 9, a remainder of 0 equals 9. Thus, Thomas’ remainder is 3 and Leopold’s remainder is 9. The remainders 3 and 9 are to be found in the first column of the Table of the Victor and the Vanquished. The second column presents the prognosticated result of which number overcomes the other, and in this case, Thomas’ number 3 is found there, thereby declaring him the victor.[8]

Suppose Thomas set out on a five-day journey to visit his friend, and he wanted to know whether the third day would end good or badly. Perhaps he wants to know if he will cover a great distance, making good time, or he worries if he might encounter highwaymen. At the very moment of questioning the matter, just as it is practiced in horary astrology, Thomas determines that the planetary hour is Mars. Thus, Mars’ number 5 is divided by 9, which gives a remainder of 5. The pair of remainders, 3 and 5, are consulted in the Table of the Victor and the Vanquished; the result is 3, predicting that Thomas’ third day in his journey to see his friend will have a good outcome.

If Thomas were to fall sick, his remainder of 3 is compared against the remainder of the number given to the planet on whose weekday he fell sick according to the Table of the Victor and the Vanquished. The text also provides instructions on how to answer the question of which one of a married couple will survive the other (“concerning those united [by familial bonds]”), which is a question explored further in my book. To find out the answer, the numerical values of their names are added up as before, but instead of dividing by nine, the questioner is to divide by seven, and then consult the table.

There are a few variants on the Table of the Victorious and the Vanquished. I have decided to include one such variant from the Syriac Book of Medicines, translated by E. A. Wallis Budge (1913). The text reads:

"Another calculation whereby a man is able to know beforehand which of two men who are striving together (or, fighting against each other) will die.

It was made by Aristotle for King Alexander, his royal disciple, when he was waging war against Darius the Mede, and Alexander conquered Darius. This calculation is sure, and hath been well tried. It is useful to everyone who wageth war against his neighbour, and striveth in respect of matters of business, and to kings, and to all men, both little and great. Observe when thou wishest to know when [two] men are waging war against each other, which will conquer.

Take the numerical values of the letters of the name of each by itself, and take from the sum of each as many nines as there are in each, and see how many remain to thee in each case, and bear them [in thy mind]. Then come to the following letters (or, numbers), and from them thou wilt learn which will conquer.

One conquereth three, five, seven, and nine.

Two conquereth one, four, six, and eight.

Three conquereth two, five, seven, and nine.

Four conquereth one, three, six, and eight.

Five conquereth two, four, seven, and nine.

Six conquereth one, three, five, and eight.

Seven conquereth two, four, six, and nine.

Eight conquereth one, three, five, and seven.

Nine conquereth two, four, six, and eight.

And if there be two in one name, or the numbers in the two names are equal, the combatant, that is, the elder, will conquer the younger.

This calculation is a very sure one, and it is mentioned by the philosophers. When they made the calculation about Alexander's name there remained eight, and when they made the calculation about the name of Darius, there remained seven; and observe that eight conquered seven, so it cometh in one case after another, with the thing that was lost and was found, and with the man who died, and with the man who was healed, and so on, when thou knowest well the name of the sick man and the name of the day in which he [first] perceived his sickness."

The Table of the Victorious and the Vanquished demonstrates itself to be a versatile onomantic device for answering a few questions about the outcome of a person’s sickness, what events might occur while traveling abroad, and the winner of a contest between two combatants. It is not surprising to discover that the supposed attribution is to Alexander the Great who would have had much use for its prognostic capabilities during his military campaigns. Similarly, such a prognostic tool would have been a welcomed addition to European fighting manuals, and especially in predicting the outcome of duels. Onomancy would later gain traction during the Renaissance and Early Modern periods, becoming a distinct art of interpretation separate from its parenthood of astrology.


Budge, E. A. Wallis, trans. and ed. Syrian Anatomy, Pathology and Therapeutics, or "The Book of Medicines," vol. 2. New York: Oxford University Press, 1913.

Burnett, Charles S. F. "The Eadwine Psalter and the Western Tradition of the Onomancy in Pseudo-Aristotle's "Secret of Secrets"." Archives D'histoire Doctrinale Et Littéraire Du Moyen Âge 55 (1988): 143-67. Accessed November 30, 2020.

Castle, Matthias. Ars Notoria: The Notory Art of Solomon. Rochester, VT: Inner Traditions, 2023.

Palazzo, Alessandro, “Origin, Development, and Decline of the Western Geomantic Tradition,” in “Documenti e studi sulla tradizione filosofica medievale,” XXXI (2020), 417-440.

The image associated with this blog entry comes from an incomplete fighting manual held at Paris, Musee De Cluny, Musee national du Moyen Age, Cl. 23842, late fifteenth century.

[This article is an expansion upon a passage from my Ars Notoria: The Notory Art of Solomon (Inner Traditions, 2023). This blog entry is Part I of III on a series of onomancy.]

This digital edition by Matthias Castle, Copyright 2023. All rights reserved.

Please do not copy this text to your website, or for any purpose other than private use.

Ars Notoria: The Notory Art of Solomon translated by Matthias Castle, published by Inner Traditions International and Bear & Company, © 2023. All rights reserved. Reprinted with permission of publisher.

[1] This particular form of the onomantic method was also called the “sortes per nomina secundum numerum litterarum (sortilege through names according to the number of letters).” Sortilege is the ancient Roman practice of casting lots (sortes), which is where we get the words “sorting,” “sorcery,” and “sorcerer” from (Latin sors). [2] Alexander the Great (c. 356 – 323 BCE) was the king of the ancient Greek kingdom of Macedon who had founded one of the largest empires in history, stretching from Greece to India. He was tutored by the famous Greek philosopher Aristotle. [3] Also known as the Sirr al-Asrar, the oldest extant editions claim to be based on a ninth century Arabic translation of a Syriac translation of a lost Greek original. [4] Pythagoras (c. 570 – c. 495 BCE) was the ancient Greek philosopher to whom various mathematical and numerological calculations were attributed. [5] Claudius Ptolemy was the famed second-century astronomer and author of the Almagest and the Tetrabiblos. [6] The identity of Abreo is unknown, although this may be a misspelling of Abez, that is, filius Abez (“the son of Abez”), who questioned the announcer of God (nuntius Dei), that is, the prophet Muhammad about the ‘science of the line’, that is, geomancy. This is recorded in the geomantic treatise known as Estimaverunt Indi. See Palazzo, Alessandro, “Origin, Development, and Decline of the Western Geomantic Tradition,” in “Documenti e studi sulla tradizione filosofica medievale,” XXXI (2020), 417-440. [7]Burnett, Charles S. F. "The Eadwine Psalter and the Western Tradition of the Onomancy in Pseudo-Aristotle's "Secret of Secrets"." Archives D'histoire Doctrinale Et Littéraire Du Moyen Âge 55 (1988): 143-67. Accessed November 30, 2020. [8]This is another kind of calculation originating with the Greeks called pythmenes (“roots”). In this computation each letter of the Greek alphabet is assigned a single digit value while ignoring magnitude. Thus, alpha through theta is 1 to 9, respectively, then iota through pi is 1 to 8, respectively, and rho through omega is 1 to 8, respectively. This is called “Pythagorean calculus” and is found in Hippolytus’ Refutation of All Heresies 4.14. For example, if a person’s name totaled 138, then the decimal digits are added together as 1 + 3 + 8 = 12. Likewise, the decimal digits of the number 12 are added together as 1 + 2 = 3. The decimal digits are reduced to a single digit. Thus, the person’s name equals 3. This also relates to the arithmetic procedure known as “casting out nines.” Compare this computation against the other Greek method known as isopsephy.

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