The distinction between knowledge and opinion in Rep. 477c1-478a6

Plato’s argument in Rep. 5, 477c1-478a6, proves that knowledge (epistēmē) is a power different from opinion (doxa), and their objects are different in kind, too. This claim by itself would probably have been rejected by the so-called ‘sight-lovers’, i.e. people who deny the existence of Forms, so the argument uses premises that the sight-lovers would admit as true and self-evident, in order to convince them. My paper engages in the debate concerning the appropriate reading of these premises, and explains why the sight-lovers should accept something they previously would not.