Justificaton of Goodness in Antiquity

My research project focused on ancient ethics. That the debate in ancient ethics centered around an ongoing disagreement about what the best life was, has been well established. I explored the question of whether, behind this agreement, lay a deeper agreement about methodology: did the different schools (Stoics, Epicureans, Peripatetics) agree on what it would take to show that such and so was the best life, or did they disagree? If they agreed, what was the method they agreed on? If they disagreed, what different answers to the question did they offer, and did they try to overcome the disagreement? The texts I focused on included Seneca’s 87th letter, the third book of Aristotle’s Topics, various Epicurean texts, and Sextus Empiricus’ M XI.