Introduction

Socrates' exhortations in the midwife passage succeed to this extent: Theaetetus is moved to offer a definition of knowledge. “Knowledge,” he maintains, “is nothing else than perception (151e2–3).” Fully one-half the dialogue's length is devoted to the formulation and examination, the delivery and assessment, of this psychic offspring. In many ways, Plato raises the suspicion that considerations beyond the initial definition's intrinsic validity dictate this lengthy treatment. The most prominent such suggestion is that it is Socrates who gives Theaetetus' offspring its ultimate form. Through Socrates' exertions, Theaetetus' initial, ambiguous definition develops into nothing less than a comprehensive view of humanity and the whole.

Socrates' guiding hand is evident not only in this magnification of the original thesis but also in its radicalization, by which I mean its thoroughgoing sub-version of any trace of stability in either the beings or in us. In Myles Burnyeat's words, Socrates ultimately conjoins “Berkeley's dissolution of physical objects into a series of ideas perceived with Hume's dissolution of the self into a series of perceptions.” What results is an unqualified relativism in a world of universal flux. The thesis that Socrates develops ultimately denies the persistent identity of both humans and beings. Socrates achieves this outcome by linking Theaetetus' definition, Socratically interpreted, with Socratic versions of Protagoreanism and Heracleiteanism. In this mutated form, Theaetetus' newborn child must seem to him to have grown in some unforeseen ways.