Much o philosophy deals wi the subject o knowledge; the philosophical study o knowledge itself is cried epistemology. Thes branch o philosophy haes bin developed bi varioos ancient Greek teachers, specially Platae, fa defined knowledge as "aw belief at is baith true an justified". He described thes idea in his dialogue the Theaetetus.
- ""Plato on Knowledge in the Theaetetus"". Retrieved 2013-05-12.