That Aristotle criticizes Plato for separating the Forms is a fact known to every reader. However, what exactly it is that Aristotle wants to criticize has, until recently, seldom been discussed explicitly and at length, and indeed as exploration of the question has occurred, views have differed considerably. It has been proposed by some interpreters that when he criticizes Plato for separating the Forms, by ‘separation’ Aristotle means their independent existence, that is, their capacity for existing even if there were no sensible objects. But other interpreters have held that he means their numerical distinctness from sensible objects, and some writers have thought that he means both of these.

Thus despite the considerable importance Aristotle places on Plato's separation of the Forms, there is disagreement about just what he is objecting to.