Answer: Plato is an author of "dialogues" (The Republic, Laws etc etc.) where the main character is Socrates. Socrates is a philosopher who uses a special kind of dialogue (so-called dialectic dialogue or dialectic method) which leads him to the truth. In other words he follows LOGOS who leads him to uncovering the Truth.
Explanation: Greek word ALETHEIA means "disclosure" and "truth" at the same time. It means that truth is always hidden. Much older Greek philosopher (pre-Socratic) Heraclitus had a dictum: "Truth likes to hide"....it seems that Socrates/Plato followed this thesis.