This volume presents the original Arabic text of Epistle 9 of the Brethren of Purity, with a clear English translation, introduction, and notes. This epistle is a major medieval treatise on ethics and character traits, which drinks from two sources: the Greek tradition, especially Plato, Aristotle, and Galen; and Islamic revelation.· Presents the original text with a clear new English translation· Includes notes to technical concepts and obscure passages· Provides an Introduction to the text, translation and edition· The Epistles is a classic work of medieval Islamic learningThe 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.This volume presents the original text of Epistle 9, with a clear English translation, introduction, and notes. This epistle is a major treatise on ethics and character traits, which drinks from two sources: the Greek tradition, especially Plato, Aristotle, and Galen; and Islamic revelation. A true repository of virtues and vices, it explores four causes for the diversity of characters, defines five types of souls, and divides society into eight classes. The authors emphasize the dichotomy inward/outward, elevating the guides of the inward interpretation of revelation. They also include a sophisticated understanding of the symbolic meaning of Satan, which could be described as 'spiritual psychology'. The concept of renunciation of worldliness dominates the second half, as do descriptions of the 'Friends of God' as epitomes of moral virtues. Overall, the epistle contains numerous illustrative stories, an unusual number of Qur'anic verses and hadith, and also rare examples of pseudo-quotes from the Biblical tradition and munajat-style texts.