Fakhr al-Dīn al-Rāzī was a celebrated theologian and scholar who composed important and often encyclopaedic treatises on a wide variety of subject. Amongst his numerous writings was a treatise on astrological magic (Kitāb al-Sirr al-maktum fir mukhatabat al-nujum) and a treatise on physiognomy.
For his life and writings, see G.C. Anawati, 'Fakhr al-Dīn al-Rāzī' in EI (2nd ed.), vol. 2, pp. 751-5. For his astrological-magical writings, see Ullmann, Natur, pp. 388-390, and for his treatise on physiognomy, see Yusef Mourad, La physiognomie arabe et le Kitab al-firasa de Fakhr al-Dīn al-Rāzī (Paris, 1939).