[Footnote 16: Aristotle (Metaphys. A. 991, a. 20) characterises this way of presenting the Platonic Ideas as mere [Greek: kenologi/a] and poetical metaphor. See also the remarkable Scholion of Alexander, pp. 574-575, Brandis.] [Footnote 17: Plato, Parmenid. pp. 132-133. This is again a repetition, though differently presented, of the same argument--[Greek: o( tri/tos a)/nthrôpos]--enunciated p. 132 A.] [Side-note: If Ideas exist, they cannot be knowable by us. We can know only what is relative to ourselves. Individuals are relative to individuals: Ideas relative to Ideas.] 5. Here are grave difficulties (continues Parmenides) opposed to this doctrine of yours, affirming the existence of self-existent, substantive, unchangeable, yet participated, Forms. But difficulties still graver remain behind. Such Forms as you describe cannot be cognizable by us: at least it is hard to show how they can be cognizable. Being self-existent and substantive, they are not _in us_: such of them as are relative, have their relation with each other, not with those particular objects among us, which are called _great_, _little_, and so forth, from being supposed to be similar to or participant in the forms, and bearing names the same as those of the Forms. Thus, for example, if I, an individual man, am in the relation of master, I bear that relation to another individual man who is my servant, not to servantship in general (_i.e._ the Form of servantship, the _Servus per se_). My servant, again, bears the relation of servant to me, an individual man as master,--not to mastership in general (_i.e._ to the Form of mastership, the _Dominus per se_). Both terms of the relation are individual objects. On the other hand, the Forms also bear relation to each other. The Form of servantship (_Servus per se_) stands in relation to the Form of mastership (_Dominus per se_). Neither of them correlates with an individual object. The two terms of the relation must be homogeneous, each of them a Form.[18] [Footnote 18: Plato, Parmenid. p. 133 E.] [Side-note: Forms can be known only through the Form of Cognition, which we do not possess.]