"The 'perfect' of a thing is a concept that we use to visualize what the 'best' of that thing would be, and by visualizing that concept of the 'best' of that thing, we can more easily work toward our target of approximating it. And even though we know from the start that the 'perfect' is not attainable for us, it still serves as a very valuable tool for us in calculating out actions, because there is no way we can hope to come close to a goal unless we start out knowing what the goal is."
I like that. I would see it then as an "ideal" not in the sense of Platonic idealism but more like:
Ideal
2: one regarded as exemplifying an ideal and often taken as a model for imitation
3: an ultimate object or aim of endeavor : GOAL
Epicurus’ living as a god?
Or a telos -- a la eudaimonia?