Answer:
The Theatetus
Step-by-step explanation:
In this text, Plato examines the question
"What is knowledge?"
The book portrays a dialoge between Socrates, his life long companion and Theatetus, a young student.
They discuss : knowledge as perception; knowledge as true belief; knowledge as true belief plus an account true judgment with appropiate articulation.
There is a philosophical exploration to conclude however what knowledge is not.
The value of this text, since we are better offered what knowledge is not
and leaves us ready to engage into the Sophist, his next dialog with Socrates.
Again the text is the foundation for platonic Epistemology, the nature of knowledge and is the main text where the ideas of Plato are to be found discussing the pre existing notions that were at his time seen as valid sources of knowledge.