precisely. He gives linguistic expression to this through nominalization (185 c 9 ff.):

Οὐσίαν λέγεις καὶ τὸ μὴ εἶναι, καὶ ὁμοιότητα καὶ ἀνομοιότητα, καὶ τὸ ταὐτόν τε καὶ τὸ ἕτερον, ἔτι δὲ ἕν τε καὶ τὸν ἄλλον ἀριθμὸν περὶ αὐτῶν.

'Being and non-being, identity and non-identity, sameness, countability.'

This nominalized grasping of the excess is not without significance. Theaetetus adds, on his own account:

δῆλον δὲ ὅτι καὶ ἄρτιόν τε καὶ περιττὸν ἐρωτᾷς, καὶ τἆλλα ὅσα τούτοις ἕπεται,

'In some cases we also perceive odd and even and the like',

thereby making the fundamental point that to this excess there belongs everything ὅσα τούτοις ἕπεται, 'which follows from what has already been shown'. This does not refer to what occurs in later, differently directed perceptions, but means all determinations that can be built up from being and non-being, sameness and difference, identity and non-identity etc., all the concrete characters which in their content essentially involve and presuppose being, i.e. every being such-and-such - as that which determines beings as the beings they are. In this way Theaetetus shows not only that he grasps the full scope of this excess of perception, but that he is himself able to pose Socrates' question in all its sharpness (185 d 3 f.):

διὰ τίνος ποτὲ τῶν τοῦ σώματος τῇ ψυχῇ αἰσθανόμεθα.

'through which bodily organs does the soul perceive the perceptions [of the indicated excess]'.

This is important because it now becomes clear that the soul also needs a δι᾽ οὗ. At first the question was: ᾧ or δι᾽ οὗ? We now see that in the new version of the question both are taken together, ᾧ (ᾗ) and δι᾽ οὗ, but without them any longer being confused with one another. The soul is that which, ᾧ ..., that which carries out the perceiving, that which perceives; the question remains, δι᾽ οὗ . . . , through what, in what way, does it perceive the totality of the perceivable.

Socrates confirms to Theaetetus that he is 'doing well' in his elucidation of the question:

Ὑπέρευ, ὦ Θεαίτητε, ἀκολουθεῖς, καὶ ἔστιν ἃ ἐρωτῶ αὐτὰ ταῦτα. (185 d 5 f.).

'Bravo, Theaetetus! You follow me exactly; that is just what I meant by my question.'

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