M. J. Levett's elegant translation of Plato's _Theaetetus_, first published in 1928, is here revised by Myles Burnyeat to reflect contemporary standards of accuracy while retaining the style, imagery, and idiomatic speech for which the Levett translation is unparalleled. Bernard William’s concise introduction, aimed at undergraduate students, illuminates the powerful argument of this complex dialogue, and illustrates its connections to contemporary metaphysical and epistemological concerns.