 Suhraward’s concept of light manages to ‘disrupt’ the classical Peripatetic ontology by rendering obsolete the Avicennan distinction between ‘essence’ and ‘existence’ in contingent beings (Rizvi 2000). Perhaps following Aristotle, Avicenna favored the primacy of essence over existence, the latter being considered an abstract concept. Suhrawardi criticized and rejected the Peripatetic logical distinction between the two concepts, insisting that the concept of existence is added to quiddity in re, such that the general extension of the concept of existence remains a mental predicate, not a real one. Concepts such as being, thingness, etc. that Peripatetics considered a priori and real are, for Suhrawardi, ‘beings of reason’ (i‘tibar ‘aqli), i.e. “merely mental considerations (i‘tibari) with no corresponding reality” (Rizvi 1999, 222; PI, §68, 56; Suh. 1993a, 175–6). This is what some have labeled Suhrawardi’s ‘conceptualist’ position, essence and existence being distinct only in the mind, and his ‘anti-realist’ approach to existence, a notion predicated only of concepts in the mind (Benevich 2017, 206, 251), a possible later Nasir al-Din al-Tusi inspired reading. 