*"Kitāb al-Madkhal fī al-Mantiq", sulla logica. ###>This work and the "Kitab al-Istiḳat" were severely, criticized by Maimonides in a letter to Samuel ibn Tibbon ("Iggerot ha-Rambam", p. 28, Leipsic, 1859), in which he declared that they had no value, inasmuch as Isaac Israeli ben Solomon was nothing more than a physician.