In order to properly demarcate the structure of the universal against other categories of the logic, Hegel makes an effort to compare the concept with categories from the logic of Being and Essence. One of the big mistakes of the tradition, for Hegel, is the mistake to universal for the one, which is a category in the logic of Being. Essence is that which posits or mediates that which is mediated. It is that first thought-determination of the logic of Essence, which arises from measure and the regress of measures in the logic of Being. Since the illusory being is posited, and what is posited requires something that posits it, illusory being points to the positer, Essence, as its origin. In self-differentiation or pure ideality, there is the unification of both types of ideality in ideality itself: self-differentiation.