The Brethren of Purity (Arabic: إخوان الصفا, romanized: 'Ikhwān aṣ-Ṣafā') was a secret society of Muslims founded in Basra, Iraq, made up of Arabs. They wrote a large philosophical and religious encyclopedia called "Epistles of the Brethren of Purity and Loyal Friends" sometime in the second half of the 10th century CE, during the Islamic Golden Age.^[1][2]

Their Epistles covered many subjects, including mathematics, music, logic, astronomy, and the physical and natural sciences. They also wrote about the nature of the soul, and about ethics, revelation, and spirituality. The Ikhwan were influenced by Ancient Indian and Persian writings, and they were strongly inspired by Greek thinkers such as Pythagoras, Socrates, Plato, Aristotle Euclid, and Ptolemy.^[3]

In their Epistles, they used not only the Qur'an but also the Torah and the Gospels. They treated these earlier scriptures as almost the same as the Qur'an. They quoted the Hebrew Bible, used Rabbinic stories, and also had some knowledge of the New Testament. They recommended reading the Abrahamic scriptures and the Injil, because they said these books came from angelic and divine inspiration. Because of their textual legacy, many scholars hold the Brethren to be freethinkers who transcended sectarian divisions among Muslims (see: non-denominational Muslims).^[4][5][6]

• Muslim Hebraists
• Islamic philosophy
• Ancient Greek philosophy
• Islam

1. ↑ "Ikhwān aṣ-Ṣafāʾ | Muslim Brotherhood, Islamic Enlightenment & Rationalism | Britannica".
2. ↑ https://backend.idat.edu.pe/Download_PDFS/T6cSxt/706752/Epistles%20Of%20The%20Brethren%20Of%20Purity.pdf^{[permanent dead link]}
3. ↑ "Brethren of Purity".
4. ↑ Whittingham, Martin (23 November 2020). A History of Muslim Views of the Bible: The First Four Centuries. Walter de Gruyter GmbH & Co KG. ISBN 978-3-11-033588-0.
5. ↑ "Archived copy". Archived from the original on 2026-03-13. Retrieved 2026-05-02.{{cite web}}: CS1 maint: archived copy as title (link)
6. ↑ "Brethren of Purity".