Full Idea
If true belief is no different from knowledge, then we must count all the things we perceive with our bodily senses as the most reliable thing in existence.
Gist of Idea
If knowledge is just true belief, we are forced to rely on the senses
Source
Plato (Timaeus [c.362 BCE], 51d)
Book Reference
Plato: 'Timaeus and Critias', ed/tr. Waterfield,Robin [OUP 2008], p.44
A Reaction
Timaeus goes on to explain how knowledge differs from true belief, roughly in the way outlined in 'Theaetetus'.