Metrodorus stresses the importance of both kinds of pleasures, but he also wrote a book entitled "On the Source of Happiness in Ourselves being greater than that which arises from Objects."
Hi, Don!
I think I have another possible interpretation of Metrodorus' book title. This is the idea: who is "ourselves" referring to? The first and obvious interpretation is "each one of us, internally". Another possible interpretation is "us, as a community of epicurean friends".
What I mean is that we can derive two very different ideas from the title of the book. The first one is, I think, in some sense ascetic, or individualistic: "I can be happy and have pleasure by myself. I don't need the objects around me" (I'm exaggerating for clearness). The second one is more social: "the greatest pleasures are not in wine, banquets, money, etc. The greatest pleasures are in ourselves, people, in the moments we have in our community with our friends".
All this depends, of course, on the ambiguity of the "ourselves" in English, so if it doesn't exist in Greek, just ignore my comment 😅
In any case, my own opinion about katastematic pleasures is that I think they don't derive from epicurean physics, so the only reason we can have to defend them must be a practical reason. So, if we accept the distinction between kinetic and katastematic pleasures, it must be because is useful for having a joyful life.