The big question is how intercessory prayer fits into this, such as indulgences. Indulgences for ourselves I can understand...it is part of the "perfecting of repentence" mentioned before. But indulgences for others? My own theologically unsophisticated view on things goes like this: the soul in purgatory is there precisely because it has lived some degree of hardness of heart, and therefore not been in perfect harmony with the will of God, whether through sin or 'imperfections' (to use St. John[ of the Cross]'s term), and it remains in purgatory until it is. When someone undertakes a penance for the soul, it is somehow exposed to it (especially the love with which the penance was undertaken), and this 'softens' whatever hardness still remains (in whole or in part) so that the soul ceases living its own resistance to grace and is able to repent more perfectly.
On reading this, my first thought was, "I guess he doesn't really understand the mechanics of purgatory either."
But that's okay. We just have to use the system, not operate it. I don't really understand the telephone network, but I know how to use a telephone. (Actually, I'm not sure I could explain how a toaster works without using the term "doohickey.")
And what we know of how to use the purgatorial system, if I may so speak, probably suffices for our needs: We offer prayers for the dead, and these prayers help the souls in purgatory attain heaven.
Now, I would like to know all that can be known about purgatory, and I think Fr. Dowd's idea that the souls in purgatory share "somehow" in our love might have something to it. But I also know that I have not fully appropriated into my spiritual life this dogmatic truth:
My prayers help souls attain heaven.
And that's a truth that, if contemplated, will produce more fruit (if fewer words) than all my speculating about distinctions between punishment and reorientation in purification.