Summary: Plato’s imagery of reflection that describes the level of eikasia in the similes of the
Line and the Cave (books 6 and 7 of the Republic) is interpreted in the light of the physiological
observations that the philosopher makes about the creation of images in mirrors and
other polished surfaces in the Timaeus and the Sophist. On that basis, it is argued that books
2, 6, and 7 of the Republic help us re-read book 1 and place Thrasymachus inside the Republic’s
Cave and at the Line’s lowest cognitive level of eikasia and Glaucon (Socrates’ most supportive
interlocutor in the Republic from book 2 onwards) at the Line’s cognitive level of
pistis (‘true belief ’). This interpretation aims at throwing new light on Plato’s much-disputed
dianoëtic level of eikasia, the philosophical validity of which commentators in the field have
seriously contested due to its imagistic language.