 E. J. Lowe takes categories to be categories of “what kinds of things can exist and coexist” (2006, 5). Such categories, he argues, are to be individuated according to the existence and/or identity conditions of their members; fundamental categories are those regarding which the existence and identity conditions for their members cannot be exhaustively specified in terms of ontological dependence relations they bear to entities of other categories (2006, 8). Accordingly, he argues that there are four fundamental ontological categories: objects (individual substances such as Fido), modes (property or relation instances such as Fido’s four-leggedness), kinds (substantial universals such as the kind dog), and attributes (property or relation universals, such as being four-legged). But although he argues that there are exactly four fundamental categories, Lowe nonetheless takes a hierarchical approach to arranging categories. The four fundamental categories appear at the third level of his hierarchical chart; the categories that appear at the higher levels (particulars and universals at the second level; entity at the top) are “mere abstractions and do no serious ontological work on their own account” (2006, 39). His fuller chart of categories appears as follows: