There are three things here: the nature in the particular, the haecceity, and the particular itself. Each of these is numerically one (and thus numerically distinct from the corrrelative items in any other particular). The haecceity is ‘primarily’ numerically one, because its numerical unity is a basic feature of its. The particular is per se numerically one because it includes the component in virtue of which it is numerically one. The nature in the particular is denominatively numerically one.