At some point, I think the group should read some of Plato’s Socratic Dialogues. In particular, I was thinking of Plato’s “Apology” and his “Euthydemus.”
Simply put, the Stoics saw themselves as the spiritual successors of Socrates and his philosophy. Plato’s “Apology” not only has Socrates explain his philosophy, but it beautifully demonstrates the implications of embracing such a philosophy as a way-of-life. Plato’s “Euthydemus” is a short read that the Stoics themselves hold in high regard. In one fascinating passage among many, Socrates defends his (and the Stoic’s) belief that wisdom is the only truly good thing, the only thing necessary and sufficient for a happy life.
Massimo Pigliucci discusses the importance of the Euthydemus HERE.