  In 187b4–8, Theaetetus proposes a second definition of knowledge: (D2) “Knowledge is true belief.” D2 provokes Socrates to ask: how can there be any such thing as false belief? There follows a five-phase discussion which attempts to come up with an account of false belief. All five of these attempts fail, and that appears to be the end of the topic of false belief. Finally, at 200d–201c, Socrates returns to D2 itself. He dismisses D2 just by arguing that accidental true beliefs cannot be called knowledge, giving Athenian jurymen as an example of accidental true belief.