[MUSIC] Ikhwān al-Ṣafā’ (or Brethren of Purity) is the name adopted by a mysterious group of Muslim thinkers from the Middle Ages, who wrote an encyclopedia with no equivalent during that period either within or outside the Islamic world. This encyclopedia takes the form of a corpus of about 50 epistles, each meant to cover a specific science or type of knowledge, and so arranged as to enable the suitably qualified person to make a progression through the noble sciences towards the most ineffable wisdom. Exactly who the Ikhwān were and where they lived has a been a matter of dispute for ages, and the question remains debated even today. It is usually believed that these authors were active in Iraq in the tenth century, but, in fact, the composition of the corpus may well have extended over various generations, and its actual inception could even have been earlier. What is now becoming increasingly clear is that the authors were Neoplatonist philosophers who must have had at least some affinities with Ismailism, a particularly intellecualizing sub-branch of Shī‘ism. In spite of its profoundly unorthodox character, it is also becoming increasingly clear today that their work (in which an attempt at explaining the universe around us is put forward in a very coherent manner) never ceased to exert an important influence over the centuries, and that this influence was far from being restricted to the world of Islam. Like various other Muslim philosophers of their time, the Ikhwān al-Ṣafā’ strove hard to reconcile the "traditional sciences," namely those sciences which could be viewed as directly rooted in the Qur’anic revelation, with the "intellectual sciences," that is, those sciences which a man is able to acquire by himself, (like logic, mathematics, the natural sciences and metaphysics) and for which medieval Islam was so indebted to the civilizations of the past: Ancient Greece, first and foremost, but also Egypt, Babylon, Iran, and India. A remarkable feature of the Brethren Encyclopedia is its emphasis on the esoteric side of knowledge and the predilection of its authors for sciences which today would definitely be ranged among the occult sciences. This may be inferred already from the classification of knowledge which the Ikhwān provide in Epistle 7: 'on the scientific arts.' This is a threefold classification of the sciences in which a group of "propaedeutic sciences" (in other words, sciences that were created for the happiness of man in this world) precedes the other two groups of superior sciences whose mission is to assure man's happiness in the next world, namely, the religious sciences on the one hand, and the rational and philosophical sciences on the other. This said, it appears at once that each of the three groups, as defined by the Ikhwān, includes sciences or arts of an esoteric nature. Thus, the group of propaedeutic sciences includes divination, magic, enchantments, alchemy. The group of religious sciences includes an explicit reference to the "science of interpreting dreams." As for the group of philosophical sciences, it contains a section about angelology. In fact, as was observed by Pierre Lory, the three full division of the Brethren's overall classification fits nicely with the three different aspects of the occult sciences as they were conceived and practiced during the Islamic Middle Ages. First, one finds the purely utilitarian aspect of magic, which is designed for man's comfort and which seeks to assure him health and wealth in this world. Then, the religious life also benefits from certain "esoteric" practices, like dream interpretation, and this is legitimized in Islam by some ḥadīth, and even by some Qur’ānic passages such as the story of Joseph. Now, it remains that "the great Magic," the one which the Brethren are most concerned with, is that by whose knowledge a man is, as it were, born to his "true" being. The importance of magic for the Ikhwān is made especially clear from the fact that the very last epistle of the corpus, that is Epistle 52, is entirely devoted to it. What is more, the authors explicitly mention, in the introduction to this treatise, that magic, and presumably the rest of the related esoteric sciences as well, "are part of philosophy, and that it is moreover part of the ultimate sciences of philosophy, since it is necessary to learn the preceding sciences before it." The manuscript tradition of this treatise has recently proven to be more complex than previously assumed, since at least two different versions are known to have circulated. The shortest version, which has now been critically edited, bears the following title: "On the quiddity of magic, incantations, the evil eye, incitements given to animals, intuition, and spells." Aside from magic, but obviously in close relation to it, is astrology, a science which the authors were visibly most familiar with, and to which they have devoted innumerable passages of their encyclopedia, including an entire Epistle on "cycles and revolutions." In this treatise, that is Epistle 36, the authors review a long list of celestial revolutions and conjunctions, and then proceed to mention the implications that these events exert upon the world and its inhabitants. From the coming-to-be of worms, bugs and lice, to the emergence of new religions, and empires; and from the replacing of man on the royal throne, to the interchange of mainlands and seas on the whole surface of the Earth. It would seem that absolutely nothing in this world of coming-to-be and passing-away escapes the influence of this extreme determinism. In this and other epistles of the corpus, the Brethren put forward a theory according to which the history of the world is made of a series of cycles of 7,000 years each, and each divided into 7 millennia. Every millennium is in turn said to be heralded by a prophet. Now, the interesting thing to observe is that Muhammad, the prophet of Islam, is not said to be the seventh and last one, rather he is number six, coming after Adam, Noah, Abraham, Moses and Jesus. As for number seven, the Brethren called him the “Qā’im of Resurrection”: he's the Mahdi that will come at the end of time and by whom the esoteric part of the revelation will be made plain to the whole of mankind. Needless to say, this is the kind of theory which must have been regarded as totally unacceptable for a wide range of readers and which may have prompted the authors to publish their work anonymously. [MUSIC]