Trust the Process: Geomancy’s Hidden Shuffling Mechanism and its Reassuring Function - Alma Eliaz

In this blog post, I demonstrate that the medieval divination method of geomancy involves a hidden shuffling step and explore what purpose this secret validation mechanism might serve.

Divination by sortition, also known as lot casting, has been used for millennia as a means of accessing higher realms and revealing hidden knowledge. This category includes all methods that use random choice to uncover past or future events, gain secret knowledge and make decisions.

Different forms of lot casting use different instruments, including dice, cards, sticks, beans and animal entrails. While the instruments and methods vary, most cases will involve some form of shuffling: Shaking the dice before throwing, shuffling the cards before opening them, or mixing the beans in the sack before drawing a few out. Through this action, the diviner both ensures and declares that the outcome is purely random. Without shuffling, we might suspect that the diviner has deliberately chosen an outcome that would yield a desired answer.

Geomancy is one such form of lot casting. It was widely used in medieval times throughout the Muslim empires and Latin Europe. Its Arabic name, ilm al raml ('science of the sand'), attests to the fact that it was initially based on creating and interpreting marks made in sand. Later, we find it usually conducted using ink and paper. Medieval instructional treatises specify possible answers to different questions and show that geomancy was mostly used for decision-making. People would turn to geomancers for advice on matters such as buying land, embarking on a journey or deciding on an engagement. The answers were obtained through a long and complex process that required skill and expertise.

The geomantic process consists of a series of consecutive steps. It can be described as an algorithmic process initiated by drawing 16 random numbers. Traditionally, these numbers are obtained by marking 16 rows of dots, with an arbitrary number of dots in each row. It is this first step that makes geomancy a form of lot casting.

However, if a person consciously marks these dots, the process does not seem so random. Although medieval geomancy manuals clearly state that the dots should not be counted while being made, it is only natural to suspect that geomancers could ignore this rule and cheat to obtain the desired answer. Could they?

Not so easily, actually.

This is because the algorithmic process used in geomancy involves shuffling. Unlike most methods, however, the shuffling step in geomancy is not visible or performative. In fact, it is hidden within the divinatory process.

As the shuffling mechanism is only visible to the user, I did not become aware of it until I first started experimenting with the method. As part of my research into the early use of geomancy in the medieval Jewish world, I tried using the method to understand how it worked. My aim was to 'get to know it from the inside' in order to better understand my sources. While documenting my experiences, I once tried to demonstrate how a particular answer was obtained. However, as I had only recorded the last step of the long process, I realised that I could not reverse-engineer it to show the preceding steps. This experience made me realise that, to produce a certain outcome, I would need to memorise the entire sequence leading to it, to realize that geomancy contains a shuffling mechanism.

To understand how this works, we need to examine the process that leads to the creation of the geomantic chart — the final arrangement of figures that is interpreted.

As mentioned above, the first stage consists of making sixteen rows of dots. While drawing the dots, the geomancer should concentrate on the particular question whose answer is the object of the geomantic consultation. The dots should not be counted as they are made, allowing the hand to draw freely any number of dots on each row.

Once all the dots have been made, it is determined whether each row has an even or odd number of dots. If the number is even, the row is represented by two dots, if the number is odd, then a single dot is used. The dots are then divided into four sets, yielding four figures, each consisting of a column of four entries, each containing one or two dots.

These four figures are usually referred to as "the Mothers" and are arranged in a line from right to left. From these four mothers, all the rest of the geomantic chart is derived.

The fifth figure is formed by working from right to left and assembling the dots in the top row of the 'Mothers' as a column from top to bottom. The sixth figure is formed in a similar way, but this time using the second row of the 'Mothers'. Figures seven and eight are formed using the same principle. These four figures are called 'the Daughters'. We can view the aforementioned process as a matrix transposition operation by considering the four Mothers as a 4x4 matrix consisting of entries of either one or two dots. Reflecting this matrix along the diagonal from the upper right corner to the lower left corner leads to the creation of the matrix of the four Daughters.

From these eight geomantic figures, four more are now produced by a binary operation which will be referred to as conjugation and be represented by the symbol (+). Two figures are conjugated by adding the dots on each level, and denoting the sum by one or two dots depending on whether it is odd or even.

When this operation is applied to each adjacent pair of figures from right to left, a row of four new figures is produced. Conjugation is then applied to the adjacent pairs in this row, yielding two more figures, sometimes called 'witnesses'. These two figures are then conjugated to produce the final figure, known as 'the Result' or 'the Judge'.

As mentioned, once the first four figures have been obtained, the remaining figures are produced by either transposing a 4x4 matrix or performing the binary conjugation operation. As this process is fully algorithmic, the initial four figures (or the initial sixteen numbers) determine the final outcome.

Since a geomantic figure consists of four entries each of which can be one or two dots, there are a total of 2^4=16 distinct figures. The geomantic chart is interpreted according to the meanings attributed to each figure and its position in the chart. Unlike the algorithmic process described above, which is pretty consistent over time and place, the rules for interpretation vary from tradition to tradition. Nevertheless, many traditions attach great significance to the last three figures, so I will use these to demonstrate a general principle that also applies to the whole chart. Namely, that the outcome cannot be easily chosen by the geomancer.

If we take the last three figures as our 'outcome' — the signs that need to be interpreted — we can now try to reverse engineer the process to obtain a desired triad. Reverse engineering the conjugation is very easy. Each figure can be obtained through the conjugation of eight different pairs of figures. Each of these pairs can be produced simply by splitting the figure. We just need to select one of these pairs and place it as the ancestors of the figure. This way, we can form the branches that split from each of the witnesses until we reach the first row of mothers and daughters.

However, there we will face a problem, because there is almost zero chance that this process will produce the correct relationship between mothers and daughters.

The transposition of the figures makes it almost impossible to reverse engineer the steps in order to obtain a certain desired answer. In this sense, it can be seen as an act of shuffling.

As mentioned above, shuffling can both ensure and declare the credibility of the random process. However, in order to declare true randomness, we would expect the shuffling to be visible to both the practitioner and their client. In the case of geomancy, though, the shuffling mechanism is somewhat hidden. How, then, should we understand its function? If one does not know that the figures have been shuffled, how can one trust the divination? To answer this question we need to remember that while the shuffling mechanism is hidden from the client, skilled practitioners were probably aware of its existence. In this sense, the shuffling mechanism could in fact play a role in building trust between geomancy users.

The modern theory of the placebo effect highlights the importance of trust in successful medical and other healing encounters. If we consider the geomantic encounter to be a form of consultation, trust may well have played a central role in its success. Taking into account that successful healing is not only dependent on the patient’s trust, but also on the physician’s belief in the process, as demonstrated by the double-blind research method, further insight could be gained into the potential of even a hidden shuffling process to build trust.

function, one which is directed towards the user. The untraceability of geomancy makes the method less susceptible to subjective intervention and manipulation. The fact that the practitioner cannot control the outcome makes the method somewhat opaque. This opacity creates a distance between the user and the method, allowing the answer to be perceived as originating from an external source.

Whether this external source was understood as divine will or the internal mechanisms that govern nature — both of which were prevalent explanations for divination in medieval times — the complexity of the process could lend it credibility in the eyes of its practitioners.

While conducting research for my MA dissertation, I consulted two Hebrew geomantic texts found in MS Magliabechiano III.36, held at the Biblioteca Nazionale Centrale in Florence. Both texts, one attributed to Abraham ibn Ezra (1089–1164), and the other written by Mordechai Finzi (1407–1476), are practical treatises that provide instructions for casting and interpreting the geomantic chart. Since my research consisted of a traditional philological analysis and practical experimentation, I became more aware of what was and wasn't present in the texts, such as certain steps in the process and references to potential problems and questions that could arise during it. The aspect of geomantic untraceability just discussed was not mentioned in these texts, and I know of no other medieval source in which it appears. Nevertheless, I believe that the absence of mention of the shuffling function in the sources does not indicate a lack of awareness on the part of medieval users. Studying the sources has taught me that, at times, pivotal elements of the practical process are absent from the written text. There may be various reasons for omitting information, ranging from the intention to conceal and protect it to a tradition of oral transmission that existed alongside textual transmission, not to mention copying errors and poor manuscript preservation.

The practical experimentation employed in this research can offer a phenomenological perspective on ancient knowledge systems. When applied to historical research, it can reveal certain hidden aspects of these systems and shed light on how manuals, instructional texts and practical treatises were manufactured, transmitted and used in ancient times.