How did Avicenna's analysis of essence and existence influence medieval metaphysics?

Avicenna’s distinction between essence and existence was a foundational element of medieval metaphysics, profoundly shaping the intellectual landscape of Western Scholasticism.12

Avicenna argued that the existence of a thing cannot be inferred from its essence alone; rather, existence must be imparted to an essence by an external agent-cause. This framework allowed medieval thinkers to conceptualize the universe as a hierarchy of contingent beings, all of which ultimately depend on a necessary, self-sufficient being—God—whose essence is identical to his existence.3

In the Latin West, Avicenna’s analysis of these metaphysical terms became a central point of reference. His work provided a rigorous vocabulary for discussing being as being (ens qua ens), which Christian philosophers like Thomas Aquinas engaged with extensively. While some Scholastics criticized his views, his influence was pervasive, as his metaphysical proofs and definitions were frequently cited to address the relationship between creation and the Creator, helping to integrate Aristotelian philosophy into the theological structures of the Middle Ages.12