But its function has to be described in terms of kinds, not individuals. But if the only real unity is numerical unity, the only real diversity is numerical diversity. But then every individual is equally distinct from every other, because everything's equally diverse, numerically, from everything else. He denies that all individuals are equally distinct, and holds that Socrates and Plato are alike just in themselves, not in anything shared in them. Their likeness, evidently, is just a bedrock fact.
Common natures are neither actually universal nor of itself particular.
Likewise, it can be abstracted by intellect and made universal. Scotus therefore accepts that universals exist only in the mind. He first considers the objection that his view leads to universals outside the mind, in things. For this to occur, the common nature must be abstracted by intellect, and made actually universal. Instead, Sc says that it can't be predicated because it's not sufficiently individual.