 Avicenna’s elaborate account of per se predication elevates the role of a technical distinction internal to the Aristotelian model and assigns it a larger and more systematic theoretical relevance, where three levels of discourse are linked in an original way: (i) the theory of per se itself, (ii) a distinction between types of metaphysical necessity of different strength, captured by the notion of containment (taḍammun) and necessary implication (iltizām), and (iii) a distinction between types of inseparability, which grounds the other two. All three levels express in different ways the dichotomy between essential and non-essential necessity (Strobino 2016b, forthcoming).