Abu al-Hasan Bahmanyar ibn al-Marzban is a notable figure among the Eastern Peripatetics, a major philosophical movement that flourished in Azerbaijan during the Middle Ages.

Unfortunately, there is scarce information regarding Bahmanyar's biography. According to the writings of Ali ibn Zayd-i Bayhaqi from the 12th century, Shams al-Din Shahrazuri from the 13th century, and various other medieval texts, Bahmanyar was born in Azerbaijan in 993. The sources indicate that he studied under Ibn Sina, resided in Hamadan for a period, and passed away in 1066, thirty years after his mentor's death.
 
Bahmanyar became a student of Ibn Sina at a very young age. Ibn Sina described his involvement in Bahmanyar 's upbringing and education, stating he loved him more than son and regarded him as "his closest and most faithful disciple."

Subsequently, Bahmanyar gained recognition as a philosopher nearly on par with his mentor, thanks to his extensive knowledge and esteemed reputation. According to a source closely associated with the era of Ibn Sina and Bahmanyar, Ibn Sina’s "al-Mubāḥathāt" ("The Discussions") predominantly highlights the subjects introduced by Bahmanyar during their discussions on complex matters. In his letters to Bahmanyar, Ibn Sina referred to him with high regard as "al-Shaykh al-fāḍil" ("the eminent Sheikh").
 
For a period, Ibn Sina provided Bahmanyar with in-depth insights into the most prominent sciences of the era and guided him closely. Eventually, Ibn Sina encouraged Bahmanyar to pursue his work independently. Bahmanyar commenced teaching at the esteemed madrasas of the East and later returned to his homeland of Azerbaijan, where he authored ten of his renowned works.

According to sources, Bahmanyar is the author of the following treatises: “Resāla fī mawżūʿ ʿelm mā baʿd al-ṭabīʿ” (“Metaphysics”), “Resāla fī marāteb al-mawjūdāt” ("Degrees of Beings"), "Ketāb al-taḥṣīl" ("Validated knowledge"), "Ketāb al-zīna fi’l-manṭeq" (“Logic"), "Faṣl men Ketāb fī eṯbāt al-ʿoqūl al-faʿʿāla wa’l-dalāla ʿalā ʿadadehā wa eṯbāt al-nofūs al-samāwīya" ("Proof of Active Minds, Showing of Their Count, and Proof of Celestial Souls"), "Ketāb fi’l-mūsīqā" ("Book of Music"), "Ketāb al-bahja" ("Book of Beauty") and “Ketāb al-saʿāda” (“Book of Happiness”).

Regrettably, many of the thinker's works have been lost. To our knowledge, only a few of Bahmanyar's writings and part of his correspondence with Ibn Sina are preserved in libraries located in Tehran, Cairo, Beirut, Lahore, Istanbul, London, Tashkent, and St. Petersburg. Among the philosophical texts that have survived, the original treatises "Resāla fī mawżūʿ ʿelm mā baʿd al-ṭabīʿ" ("Metaphysics") and "Resāla fī marāteb al-mawjūdāt" ("Degrees of Beings") were published in Leipzig in 1851 alongside their German translation, and in Arabic in Cairo in 1911.

Bahmanyar's comprehensive work "Ketāb al-taḥṣīl," divided into three books, Logic, Metaphysics, and the Study of the Dispositions of the Essences of Beings ("ahwāl a‘yān al-mawjūdāt") was published in its original Arabic in Tehran and Cairo. A Persian translation of the treatise also exists; according to some medieval sources, Bahmanyar himself, too, was involved in translating it into Persian. One copy of this Persian version is preserved in the manuscript collection of the Institute of Oriental Studies of the Academy of Sciences of Uzbekistan. Additionally, A.V. Sagadeev, a notable scholar of medieval Eastern philosophy and a Doctor of Philosophical Sciences, translated "Ketāb al-taḥṣīl" into Russian, with the three volumes published in Baku (Volumes I and III in 1983 and Volume II in 1986).

Bahmanyar significantly contributed to the development of philosophical thought in the Muslim East during the Middle Ages. Abu al-'Abbas al-Lawkari and Omar Khayyam were his direct students. Additionally, his school produced notable naturalist philosophers such as Athir al-Din al-Abhari, Afdal al-Din Khunaji, Siraj al-Din Urmavi, Nasir al-Din al-Tusi, and many others.
 

Recommended literature:

1. Mustafazadə, Nazilə Bəybala qızı. Azərbaycan - keçmişi, bu günü : toplu / N. B. Mustafazadə. - Bakı : Müəllim, 2005. - 596 s.
2. Azərbaycan fəlsəfə tarixi : 4 cilddə / AMEA Fəlsəfə, Sosiologiya və Hüquq İnstitutu; baş red. F. Q. Köçərli. I cild : Qədim dövrdən XIII əsrə qədər / red.: Z. Ə. Quluzadə, A. Ə. Hacıyeva. - Bakı : Elm, 2014. - 456 s.
3. Məmmədov, Zakir Cabbar oğlu. Orta əsr Azərbaycan filosofları və mütəfəkkirləri /Z. Məmmədov ; rəyçi. M. Mahmudov. - Bakı: Azərnəşr, 1986. - 63 s.
4. Бахманйар ал-Азарбайджани. Ат-тахсил: познание /Бахманйар ал-Азарбайджани ; пер. комментарии. : А. В. Сагадеева ; ред. Г. Б. Абдуллаев, Ф. К. Кочарли, С. Д. Рза-Кулизаде ; АН АзССР, Ин-т философии и права. - Баку: Элм, 1983. - 205 с.