The second volume of Plato’s Collected Works includes 6 dialogues from the philosopher’s mature period (80–60s of the 4th century BC): “Phaedo,” “Symposium,” “Phaedrus,” “Theaetetus,” “Sophist,” and “Parmenides.”
If the themes of the first volume are predominantly ethical, then in the dialogues included in the second volume the central focus is Plato’s teaching about Ideas.