How do Socrates and Plato arrive at the requirements for what we have well-founded knowledge of, as opposed to what we merely assume or are convinced of?
I know they came to an “agreement” in Plato’s Theaetetus, that knowledge is “justified true belief.” But I have a difficulty in understanding how they came to those requirements.
Answer by Jürgen Lawrenz
Your difficulty stems from the very different attitude to knowledge bred in our scientific civilisation; and so it is difficult to ‘unthink’ what is evident to us, for the sake of understanding thinkers who were trying to smoothe a path that we tread without much effort. For example, the ‘agreement’ between Sokrates and Theaetetus is not quite so comfy as you seem to believe. It is constrained by what we today would call “hard knowledge”; but they also come to the conclusion that a description is not a necessary adjunct, as a person may well entertain a “justified true belief” without being able to give an account of it. Thus a surgeon may be in complete command of his skills, yet find himself unable to articulate this knowledge with a view to teaching it. Sokrates himself takes pride in his talent for “midwifery of the truth”, while relying on others (or pretending to) to arrive at the correct conclusions. Thus the criteria of their agreement are similar to those of Gilbert Ryle’s classification of “Knowing that” and “Knowing how”.
Their enquiry therefore concentrates on eliminating from consideration all those forms of knowledge acquisition which can be identified as dubious, i.e. those which rely on (a) sensory perception; (b) the relativism promoted by the ‘homomensura’ argument of Protagoras; (c) the ambiguities arising from the theory of flux of Herakleitos; (d) issues where different people may have different opinions based on their experience (the ‘alladoxia’ problem); and (e) contingent knowledge (i.e. the ‘cold wind argument’) that can be true or false depending on conditions. These are some of the main criteria, though by no means all. In any case, a reader can gain further insight into these aspects from the divisions of the soul (“the divided line”) which Plato expounds in the Republic Although the theory of forms is hardly broached in the Theaetitus, it is presupposed as the ultimately relevant reference. The dialogue therefore seems to enlarge the scope of the earlier debate to make it serve as a detailed ‘case study’.