The Epistles are named after a confraternity who wrote, published and disseminated this encyclopedia known as İhvan-i Safa [inTurkish] [Epistles of the Brethren of Purity] today. In the past these Epistles were also referred to in Arabic as Epistles of the Brethren of Purity or The Brethren of Sincerity—a giant compendium of 52 epistles. Although some sources claim that these manuscripts were written by contemporary scholars during the years of A.D. 961-986, these Epistles were written by a philosophical society, commonly known as a secret confraternity.
What is this secret confraternity?
Brethren of Purity is the group established in the Islamic world in the tenth century, who had religious, moral, philosophical and political targets and whose actions were based on fellowship, friendship, cooperation and solidarity in achieving these targets. Their doctrine was to redeem religion and philosophy that was spoiled by misinformation and superstitious beliefs. Therefore, to reach their goals, the Ikhvanus, namely, the Brethren, made an effort to establish a wide-based cultural infrastructure which would form the basis of their approach. Further, this fellowship always avoided becoming a religious sect and tried to keep their distance from them. Hence, they principally used all sorts of thought, regardless of origin.
Basra was the community center of the philosophical organization. One could affiliate with the organization only through personal connections and fiduciary relationships. Confidentiality was of significant importance: Never in these Epistles were member names mentioned and no one but members was authorized to participate in the meetings. Indeed, this community was active during the final realm of the Abbasids, a quite chaotic and tense period: They conducted philosophical and scientific studies emphasizing unity, oneness, fraternity and solidarity with a religious and moral attitude, and re-emphasized the intellectual orientation of the Islamic world.
The most significant feature of the Brethren of Purity was as the first secret debating society whose activities were stored in a written format. The doctrines of this society were compiled and summarized in an encyclopedia called Treatises of the Brethren of Purity. In one of these Epistles, characteristics of the members of the society were clearly depicted: virtuous, friendly, advising, mediating people who perceive the world with their heart and in divine light rather than their mind; do not let people slip off into fanciful dreams; live in bliss of the beauty and marvel of sciences; indulge in the spiritual world; mended their ways and entitled to eternal merits.
These Epistles contained knowledge that were compiled on a number of sciences—religions, cosmology, psychology, metaphysics, astronomy and mathematics—no doubt written by experts in their own subjects. Moreover, the Epistles provided a synthesis of the available knowledge of their time, with an effort to detach religion and philosophy.
What did these Epistles cover and why were they exposed for destruction? 
On a large scale, the Epistles consisted of religious motives and opinions of the Islamic philosophers, especially Al-Farabi’s. A summary of the Islamic sciences that were popular in that era are presented in the content. The Epistles were reflective of their time in every sense; hence, Islamic intellect of the era, Ancient Greek philosophy, Hindu wisdom, Farsi and Arabic literature and a variety of religions and cultures were intentionally blended and compiled. The content of the Epistles were irenic: They adhere to Pythagoras in mathematics; Aristotle in logic; Plato in metaphysics; Socrates in ethics, and Al-Farabi in religion philosophy. Especially it is easy to detect the influence of Pythagorean and Neo-Platonism in the Epistles.
The most significant feature of this work of literature, which stands as the first known written Islamic encyclopedia, was the simplicity in presenting the content so that the most sophisticated and inexplicable matter became legible. Thanks to the Brethren of Purity, Aristotle’s philosophy became public, hitherto at the service of the high society.
The Brethren of Purity regarded knowledge as purification; thus to live a pure life, one had to live in conformity with this knowledge. Likewise, according to the Brethren, there were two fundamental objectives of all theoretical and applied sciences: first to ensure physical well-being and second to ensure spiritual well-being and to assure blissfulness of the soul after death. So, according to the Brethren, apparent sciences realize well-being of the flesh; whereas, esoteric sciences realize well-being of the soul. In that regard, the Brethren initially aims at discovering what is available to the eye in this world of dichotomy (apparent and esoteric). Therefore, in the Epistles, knowing thyself is the first condition of metaphysics and to know the Divine.
The Epistles were written in Arabic and composed of 52 volumes, embodying mathematics, botany, nature, geography, music, logic, astrology, numeric and philosophical metaphysical sciences. Out of the 52 volumes, 14 of them were about mathematics, logic and higher education issues; 17 of them about nature and philosophy, including psychology; 11 of them on theology, Sufism, mysticism, astrology and magic. All the accumulated experience of the three major religions is intermingled in the Epistles. Moreover, there are inputs from Zoroaster’s philosophy and Hinduism. Thence, the content was structured to the secondary and higher education programs.
Depicting the spiritual and intellectual situation in the tenth century, the Epistles stood as the first study that compiled all the sub-disciplines of philosophy into a single book. In that respect, the Epistles seem to be the first written work intended for the education of society in terms of science and philosophy, a radical attempt indeed.
When was the initial destruction of the Epistles?
In A.D.1150, Mostandjed, Caliph of Baghdad, commanded a recall of all copies of the Epistles from all libraries, private and general, and setting them on fire (the same caliph ordered the destruction of the works of Avicenna). Even so, the Epistles were known to many countries; they were disseminated, translated to many languages and survived extinction. This literature reached each and every part of the Islamic world.
Starting out from Mesopotamia and passed down from hand-to-hand, the Epistles reached far out to Andalucía – thanks to a number of scholars. According to some researchers, before the Epistles arrived, Andalusians were keener on astronomy and mathematics; thereafter, they started to place more emphasis on philosophy. Likewise, these scripts had a great influence on the contemporary and next generations’ mystics: All contemporary and next generations’ scholars had read the Epistles; namely, Gazali (1058-1111), Ibn Arabi (1165-1240), Avicenna and Molla Sadra (1571-1640), etc. Also, the Epistles enlivened and influenced the Sufi philosophy of Ibn Arabi. In that regard, this work and the ideas that flourished respectfully had a remarkable effect on expansion and progress of Sufism in the Islamic world.
The Brethren of Purity studies the sciences in three main groups:
a) Mathematical (Practical – Scholastic Sciences)
1. Science of Literacy
2. Science of Language and Grammar
3. Science of Accountancy and Business Operations
4. Poetry and Rhyme
5. Doctrines of good and bad prophecy
6. Mechanical sciences, magic, amulet, alchemy, etc.
7. Various occupations and arts
8. Science of Exchange, Commerce and Agriculture
9. History and biographies
b) Religious Sciences
1. Science of Oracle and Apoplexy
2. Science of Interpretation and Commentary
3. Science of Tradition
4. Science of Islamic laws
5. Science of Advice, Piety and Sufism
6. Science of Dream Interpretation
c) Philosophical Sciences
1. Mathematical sciences
a. Arithmetic
b. Geometry
c. Astronomy
d. Music
2. Science of Logic
a. Acta Analutica (poetry)
b. Rhetoric (oratory)
c. Topica (debate)
d. Politica (science of evidence)
e. Sophistica (science of convicting)
3. Natural sciences
a. The sciences that provide information about the matter, form, time, space and movement; science of the relationships between substances
b. Science of Earth and Skies
c. Science of Flourish and Decay
d. Meteorology
e. Mineralogy
f. Botany
g. Zoology
h. Medicine and Veterinary Medicine
4. Theology
a. Science of God and associated names
b. Science of the Spiritual World
c. Science of the Universal Soul
d. Political Science
e. Science of Afterlife and Resurrection
References
The Mystery of Numbers and the Dynamics of Sufism – Ikhvanus Safa Model; Assoc. Prof. Bayram Ali Çetinkaya
“The Very First Encyclopedia of the World”; Dr. İsmail Kaygusuz
Light Comes from the East; Cemil Meriç
“Ikhvanus Safa, A Trial of Dictionary that Shed Light on the Islamic World in X. Century at the Level of Philosophy and Science”; Enver Uysal
“Fundamental Sufi Concepts and Thoughts Underlying the Brethren of Purity Thought”; Assoc. Prof. Bayram Ali Çetinkaya

Filiz Baştüzel