The Ikhwan al-Safa' (Brethren of Purity), the anonymous adepts of a tenth-century esoteric fraternity based in Basra and Baghdad, hold an eminent position in the history of science and philosophy in Islam due to the wide reception and assimilation of their monumental encyclopaedia, the Rasa 'il Ikhwan al-Safa' (Epistles of the Brethren of Purity). This compendium contains fifty-two epistles offering synoptic accounts of the classical sciences and philosophies of the age; divided into four classificatory parts, it treats themes in mathematics, logic, natural philosophy, psychology, metaphysics, and theology, in addition to didactic fables.
Epistles 43-45 succeed the extended description of religions and creeds that opens the final section of the corpus, on the theological sciences. Epistle 43 explains briefly the need for purifying one's soul by performing virtuous acts, after which one can follow the 'straight path' to God. The extremely diverse Epistle 44 is no dry exercise in abstruse theology; rather, it is characterized by the most delightful anecdotes, designed to inform the reader of a deeper truth, that of the hereafter following the soul's separation from the body at death. Alongside references to many of the Prophets encountered in the Qur'an, this Epistle shows a familiarity with other religions such as Christianity, Judaism, and Buddhism. Epistle 45 focuses on companionship and friendship, resonating strongly with the word 'Brethren' by which the authors distinguish themselves. The volume overall is united in its underlying themes of the immortality of the soul and the profound need for mutual cooperation, informed in parts by the general Neoplatonism of the entire corpus, as well as by Aristotelian and Platonic motifs.
After completing his undergraduate degree in Indian Studies at the University of Cambridge, Toby Mayer went on to study Medieval Arabic Thought at the University of Oxford, where he did his doctoral thesis on Ibn Sina's Book of Allusions (al-Isharat) and its commentaries. He has taught courses on medieval Muslim philosophy, scriptural hermeneutics and Sufi mysticism at the School of Oriental and African Studies (SOAS), University of London, and at the Institute of Ismaili Studies. Central to his research interests is the later, Isma'ili-influenced, thought of Muhammad b. 'Abd al-Karim al-Shahrastani (d. 1153), and the reception of Avicennism.
Professor Ian Richard Netton is a specialist in medieval Islamic Philosophy, Comparative Religion, and Anthropology of Religion with a particular interest in ritual. After teaching and researching at the University of Exeter for many years, he was appointed the University of Leeds' first Professor of Arabic Studies in 1995 where he also served as Director of the then Centre for Medieval Studies. In 2007 he returned to the University of Exeter where he is Professor of Islamic Studies. He is the author or editor of 22 other books and numerous articles as well as being the Series Editor for three major series: the Routledge Culture and Civilisation in the Middle East Series, the Routledge Sufi Series, and the Edinburgh History of the Islamic Empires Series.
Samer Traboulsi is Associate Professor of History of the Middle East and the Muslim World at the University of North Carolina at Asheville. He received his PhD in Near Eastern Studies from Princeton University in 2005. He is mainly interested in the formation and development of religious groups in the Muslim World and has published a book and a number of articles on the Isma'ilis in Yemen, the rise of the Wahhabi movement, and the history of Saudi Arabia.
