“Until now we’ve explained piety in terms of the things themselves we’d need to do to attain it,” Ramchal inserts here. “What we’ll discuss now are the motives behind those actions” — that’s to say, we’ll delve into what we’d need to be convinced of to be driven to true piety.
Along those lines, he points out that “we’ve already discussed the notion of acting either altruistically or for an ulterior motive before” (see 16:2 where Ramchal was rather adamant about acting altruistically), but there’s more to be said about it for our purposes now. For, the truth of the matter is that if you serve G-d for some loftier ulterior motives, you aren’t as utterly blameworthy as you might have thought.
And so, for example, if you serve G-d so that your “soul could be purified in G-d’s presence”; so that you “could merit dwelling among the just and pious” and “to ‘witness the pleasantness of G-d and to visit His Sanctuary'” along with them (Psalms 27:4); or “for a reward of the World to Come” — then you couldn’t really “be said to be ill-motivated” or self-centered.
That is, if what motivates you is a dream of sure closeness to G-d Almighty, then we’ll forgive you that “personal bent” if you will. After all, what mortal being who longs for closeness to G-d doesn’t deserve our admiration in the end? But still and all, “you couldn’t be said to have the best of intentions either”. Because at bottom we’re to set out to serve G-d selflessly, only so that “His glory grow and spread” and for no other reason.
Now, the truth be known, you could only come to that highest level “after your love of G-d is fully developed”, and you want nothing more than for His name to be honored in this world. While few of us have reached that level, to be sure, it would still do us well to know the highest, most ideal and selfless motivations behind loving G-d.