De laudibus sanctae crucis

This folio is the last in a series of 28, and superposes an astonishing number of theological messages. This was the work (during the Carolingian epoch) of the Benedictine monk Rabanus Maurus (d.856). In the poem in honour of Christ’s cross that lies at the bottom of the page, each verse comprises the same number of letters. Geometric (cruciform) figures and living beings are also represented. The letters and the verses that superpose the figures attribute the representation with a specific meaning. Thus, the figure of the kneeling monk is that of Rabanus himself, and his name appears as though it were a signature. Also integrated are acrostics, palindromes, and numerical speculations (3 being the number of God, 4 that of man, 9 the order of the angels, and 12, 28, 70, 144, etc.) expressed either by the letters’ numerical values, or by geometric diagrams. The idea was that the Cross (apart from its dogmatic significance) is the sign of a perfect harmony that encompasses the material cosmos, the heavens, the angelical orders, and divine nature itself.

This notion of universal harmony expressed through numbers and letters was well established before Christianity. It had been developed in Greek antiquity, especially by Pythagoras and the neo-Pythagorean authors. Whoever is capable of penetrating the mystery of numbers and their relationships can understand the matrix that organizes the whole universe. For example, the number 28 is that of the lunar houses, and is also a figure that equals the sum of its divisors (1+2+4+7+14): the link is made between the celestial and astral orders and the arrangement of the numbers themselves. In Judaism, many and ancient were the speculations on numbers and letters (each letter in the Hebrew alphabet has a numerical value) applied to the biblical texts, and they reached a high point with the teachings of the Kabbala (especially those of Abraham Abulafia and the Zohar in the thirteenth century, and of Moshe Cordovero and Isaac Luria in the sixteenth century).

An Islamic equivalent of the Kabbala—the ‘science of letters’—also developed, and was applied mainly to the Qur’anic texts. Each of the 28 letters of the Arabic alphabet has a numerical value. The idea that God created the world through his Word led to the concept of a world entirely constituted as and by a language: the knowledge of the secrets of the letters is the gateway to the mysteries of the heavens and the earth (hence the importance of literal speculations on alchemy). The greatest author in this discipline was incontestably ’Ibn ‘Arabī (d.1240).

It is interesting to note the convergence between Jewish, Christian, and Muslim thinking relating to this harmony of numbers and letters. The content of the various speculations is of course different: the alphabets do not entirely match (22 letters in Hebrew, 24 in Greek, and 28 in Arabic), there are divergences between the holy texts studied, and the conclusions of the speculations are also different. However, what is well and truly shared is the central idea that human language corresponds to mathematical harmony and that the structure of creation and man’s relationship to God can be expressed numerically. It sometimes leads to the conclusion that this esoteric knowledge of letters may give some power over the future, and therefore to practices associated with magic.