In this Platonic work, we will follow one of the most interesting philosophical discussions about the essence of Knowledge between the most charming teacher of European thought, the dialectical and maieutic Socrates, and the inspired student and skillful mathematician, Theaetetus. In this context, Plato's epistemological struggle - closely related to his political and ethical philosophy - will "fight" against illusion, false opinion, and ignorance, after first justifying the value of Knowledge.

Knowledge in Plato has a binding character. Its possession inevitably leads to virtuous actions. The foundations of this perspective lie in Socratic teaching (whoever knows the virtuous, does it). This ethics encompasses a strong dialectic ("one must know the right in order to do it", but also "whoever knows the right can only do it") and reflects Plato's dynamic epistemology: such is the transformation that knowledge brings to humans, that they are unable to choose any other way of action in moral and political life than the one indicated by Knowledge.

The "Theaetetus" now becomes a beacon in the dark ages to come, as it constitutes a monumental architecture of Knowledge, which will shape the reasoning of the soul and establish the conditions for the logical approach to the theory of ideas.