present discussion. Here, despite the fact that Socrates has cast himself as a mere ignorant interrogator, when the discussion turns to the soul's capacity to study the ‘commons’ independently of sense-perception Socrates is portrayed as—quite exceptionally for thisdialogue—making an open declaration of hisown conviction: ‘And aswell asbeing beautiful’, he says to Theaetetus at 185e5–9, ‘you have done well in saving me from a very long discourse, if it is your own belief that the soul examines some things through its own resources, but others through the body's faculties. For that is what I thought as well, but I wanted you to think it too.’ Plato could hardly have made it clearer that in hiseyesthis distinction between the a priori and the empirical was to be credited to Socrates himself.
The reason why, exceptionally, Socratespermitshimself to reveal hisown hand here, despite hisavowed intellectual barrenness, isno doubt once more that the tenet in question isa principle on which hisavowed expertise of midwifery is itself founded (see principle 2, p. 33 above). But Socrates' willingness, indeed eagerness, to assert it as his own view is more pronounced than any other element of assertiveness he shows in the dialogue. It can be read as Plato's way of highlighting a pivotal Socratic insight.
So much for the distinction between empirical and a priori. But need it have any metaphysical implications? Are the contents of the latter class necessarily to be identified with separated Forms? We must wait to see how the argument proceeds.
seems to have bestowed on it a richer profile. If this is not yet the philosopher's notion of being, as conveyed by such imperfect translations of ousia as ‘reality’, ‘substance’, and ‘essence’, it isat any rate something more demanding and less readily grasped than the force of everyday predications.
Thisapparent enrichment of the term gainsin credibility soon after, when Socratesaddsthe following crucial remark (186b11–c5):
Hence there are some thingswhich, from the moment of birth, are naturally available for humansand animalsalike to perceive—those experiences which reach through the body to the soul. But as for calculations (analogismata) about these things, with regard to being (ousia) and benefit, it iswith difficulty and over a long time and through a great deal of effort and education that they become available, to those to whom they do become available.
In the second sentence of this passage, Socrates appears to distinguish those who do not stop at merely experiencing sense-perceptions but go on to apply the demanding notions of being and benefit to their contents. Technically, he could mean that virtually all humans do this, but no other animals: thus, so far as ‘being’ isconcerned, the very ability to think propositionally—that is, to grasp everyday being such as in the thought that the cat ‘is’ on the mat—takesat least the first year of life to develop, and is already enough to distinguish humans from non-human animals. However, when he distinguishes these cognitive acts with the otherwise almost unattested noun analogismata, which I have translated ‘calculations’, that clearly suggests a reference to the work of the expert, given Theaetetus' preceding use of the cognate verb analogizesthai in what we have seen to be a corresponding sense. Besides, Socrates' declaration that only those who persevere with their education can aspire to these ‘calculations’ suggests something more than the ability to entertain everyday propositional thoughts.169
If so, it may seem that the ‘being’ (ousia) which isamong the objectsof these calculationsought itself not to be common or garden being, but rather that kind of ‘reality’ that only a few human beings—primarily philosophers—can grasp: the unchangeable being, in fact, which according to advanced Platonic metaphysics exclusively characterizes the intelligible world.
169 It doesnot follow that they are limited to authentic experts, since at 178d8–e8 even chefs and rhetoricians can successfully predict outcomes, despite being Socratic paradigms of pseudo-experts (see pp. 87–8 above).
On the other hand, Socrates cannot himself fully have seen this, because the ‘calculations’ in question are said by him to be ‘about these things’, that is, about sense-contents. If Socrates has started to see the link between knowledge and essences, he certainly has not got as far as the latter's metaphysical separation from sensibles.170In fact, since Socrates started out invoking a low-level concept of being, it is likely that he himself still intends no more than that: what takes yearsof hard study isnot the ability to entertain thoughtswhich include ‘be’ and ‘benefit’ assuch, but to achieve the analogismata—expertly informed inferencesfrom prior data—about these that Theaetetus has now brought into the discussion. We may take these ‘calculations’ to be appraisals of what things are and of how to achieve beneficial results—appraisals which are characteristic marks of the expert; but, at least in Socrates' eyes, they do not import any kind of being over and above that expressed by ordinary uses of the copula. The fact that the turn which the discussion has taken points readers towards a far richer sense of being is no accident, but it corresponds to Plato's more than to Socrates' take on the argument. Socrates means only to point out that being and benefit—understood in a quite untechnical sense—can become the subjects of demanding expertises.171 We should leave the contrived ambiguity in place, and read on.
Whatever kind of ‘being’ may be intended, it playsa key part in the final refutation of Theaetetus(186c7–e12), which can be summarized as follows:
(1) Knowledge entails accessing truth.
(2) Accessing truth entails accessing being (ousia).
(3) Perception cannot access being (as already demonstrated).
(4) Therefore perception cannot access truth.
(5) Therefore perception and knowledge are not the same thing.
Here too we face our usual interpretative dilemma. It could be that, in line with the thin notion of being with which Socratesopened, perception'sincapacity to be knowledge liessimply in itsinability to
170 The same point emerges from 186b6–9, d2–3.
171 While Plato's motive for reminding us of his metaphysics should be clear, it is less clear why his speaker, Socrates, includes these remarks. It seems likely enough that, since grasping truth is no more than a necessary condition of knowledge (as the Jury passage in partII will remind us, see pp. 149–50 below), Socratesassumesthese analogismata to be an additional factor in knowledge. If so, however, they play no further part in the argument, being effectively replaced in partIII by logos.
entertain propositional thoughts, all of them explicitly or implicitly expressed by the assertion that so and so ‘is’ such and such. If perception cannot think propositionally, a fortiori it cannot entertain any true propositions, and therefore cannot aspire to the status of knowledge. But it could equally be that he is assuming the much richer notion of being that emerged later on. Knowledge in thiscontext would then be, not everyday cognition, but the state of mind of the expert, and especially of the philosopher. The argument will be that knowledge in this strong sense requires access to Being in its strong sense—that is, a grasp of the ultimate reality of each thing, such as, in Plato's eyes, can be found only at the level of Forms.172 Correspondingly, ‘truth’ (alētheia) too would require a stronger sense, and one is readily forthcoming: the word can (asin the Sun simile of RepublicVI, at 509a7173) be used to single out eternal verities, and thus to connote the deep truth on which philosophical inquiry is focused.
Thisambiguity about the scope of ‘being’, ‘truth’, and ‘knowledge’ mirrorsand continuesthe earlier ambiguity about the ‘commons’—are they mere a priori predicates, or transcendent Forms? But by now we should be welcoming and exploiting these ambiguities, rather than struggling to resolve them. Once again, a division of labour between Socrates and Plato can be imposed by the reader. Socrates can be assumed still to intend no more than the weaker readings of
‘being’, ‘truth’, and ‘knowledge’. This fitsbest not only with the hard core of hisargument, but also with the fact that in the remainder of the dialogue the ‘knowledge’ which he investigates continues to include everyday cognition in its scope. The stronger, Platonizing reading, which was first casually introduced by Theaetetus, is thereafter continually hinted at by the text, but constitutes no indispensable part of Socrates' own argument.
The Socratic dimension to the argument can be located in the identification of being asa member of the set of a priori predicates, those which lie beyond the reach of perception. For this has proved already sufficient to ground the insight that perception cannot be
172 Thismight seem to conflict with Socrates' readiness in these closing pages of partI to restore to the objects of perception the ‘being’ that wasdenied to them by the Protagorean theory (157b1–7). But Plato is careful to make him assign them both being and not-being (185c4–7), thus maintaining their conformity to the status of sensibles ascharacterized at Rep. 478d5–479d5.
173 Cf. Phd. 65b9 (very reminiscent of our passage), 99e6; Rep. 585c1–d4; Ti. 29c3, 90c1–2. There are numerousfurther examplesin Plato.
knowledge. Asfor Plato, he asthe author of the Republic had started from the Socratic method of a priori investigation, but had gone on to redefine it asan ascent from the world of becoming to the pure being of the Forms; and the argument which he places in Socrates' mouth strongly hints at an enriched conception of knowledge, founded on that ontology. In the systematic ambiguities of Theaetetus 184b3–187a3, we can discern how natural was the progression from the Socratic method to the Platonic. Once more, Socrates emerges as the unwitting instigator of that progression, the midwife who brought Plato'stranscendental epistemology into the world.