One question I raised in the discussion last night Don, is whether the question is the coming and going of pleasure itself, or of the "greatest good." I know that the issues are related but is the issue that pleasure and pain do not co-exist at any moment, or is the issue related to the "greatest pleasure" (100% pleasure 0% pain) or some combination.
In other words, what is the proposed "take-away" from this saying? That pleasure and pain are the two alternative feelings, or that they never co-exist at the same moment, or what? Does adding in the issue of 'the greatest pleasure" add something to the issue that pleasure and pain do not co-exist?