Existence and the Problem of Aḥwāl: The Quiddity and Ontological Status of Existence in Avicenna and His Islamic Reception

The Avicennian distinction between quiddity and existence opens the way to several derivative issues concerning the quiddity of existence (what existence is) and the ontological status of existence (whether and how existence is). This paper presents a fine-grained account of the positions and arguments developed by post-Avicennian authors on these matters, showing how the debates on states (aḥwāl) and grounding (taʿlīl) feed into the picture. The discussions on the quiddity of existence revolve around the features of its knowability and its connection to a ground (ʿilla), or lack thereof. As for the ontological status of existence, the standard idea of a clash between realism (existence is an extramental existent) and conceptualism (existence is a purely mental existent) calls for further refinement. First, realism itself encompasses two distinct positions when it comes to the relation between the second-order existence of existence and existence itself (sameness, additionality). Second, the tradition presents other doctrines not easily classifiable within the realism-conceptualism framework (the existential non-assertability of existence, the non-existence of existence).