 Alexander of Aphrodisias. (i) Commentaries. The first book of Alexander’s commentary on the De Gen. corr., lost in Greek, is said to have been translated by Qusta ibn  Luqa,[41]  a physician and translator who came from Baalbek to Baghdad in the first decades of the 9th century and had exchanges on medical and philosophical matters with  al-Kindi.[42]  (ii) Personal works. Of prominent importance are two writings lost in Greek: On Providence (Fazzo-Wiesner 1993) and a cosmological treatise known in Arabic as On the First Cause, the effect and its movements (ed. Endress 2002). From the circle of al-Kindi comes also the translation of a series of Alexander’s genuine Quaestiones, intermingled in the manuscript sources with propositions of Proclus’ Elements of Theology, attributed to Alexander (Endress 1973; overview on the Arabic Alexander by Genequand 2011 and 2017).