Illumination (ishrāq) is a term of art in the philosophical system introduced by al-Suhrawardī (d. 587/1191). It usually occurs in adjectival form (ishrāqī) , characterising immediate knowledge as well as arguments and principles that are grounded in immediate knowledge and that depart from the Peripatetic philosophy of Ibn Sīnā (Avicenna, d. 428/1037). In this form, it became the name for Suhrawardī's philosophy in the subsequent tradition. In his preface to the Ḥikmat al-ishrāq ("The philosophy of illumination"), the foundational work of illuminationist philosophy, al-Suhrawardī sketches