In an effort to refute Avicenna’s real distinction between essence and existence, Averroes argues for an Instantiation Analysis of existence which thinks of existence not as an accidental addition to an essence, but rather as the recognition that there is an instance in extramental reality which matches a concept in the mind of a knower. In this study, I argue that Averroes’s Instantiation Analysis fails to refute Avicenna’s real distinction by showing that Avicenna himself endorses the Instantiation Analysis and, in (...) fact, makes use of it to motivate his real distinction. To show this, I review several texts where Avicenna makes the puzzling claim that substances are found to be in subjects. These texts reveal how Avicenna discovers the real distinction with Aristotle’s help—not, as Averroes relates, against the view of Aristotle. (shrink)