This publication presents a translation of the work of the first major representative of the “Western” branch of Muslim philosophy (falsafa), the Arab-Spanish philosopher Abu Bakr ibn Bajja (lat. Avempace; d. 1139). This treatise, dating back to the last years of the philosopher’s life, was written as a message to his friend and follower, the vizier Ibn al-Imam (d. c. 1152). Substantiating the doctrine of the highest happiness in this life and the next, characteristic of Falsafa’s felicitology, as the conjunction of the human soul with the upper, intelligible world (God and the cosmic intellects-angels), Ibn Bajjah puts forward an original concept of the conjunction (ittisāl) with the Active intellect (al-‘aql al-fa‘‘āl ) — the ruler of the sublunary world, which is identified with the Archangel Gabriel and from which both prophets and philosophers receive intellectual truths. At the final stage of epistemological ascent, the cognitive subject becomes one with the object as well as with the other such subjects. The translation was made from the Arabic original; it was translated into Russian for the first time.