The Awakening of Tony and other thoughts
Close to the ending of the show, Tony Soprano, after committing one of his most heinous deeds by killing Christopher Moltisanti, goes off on a pilgrimage to Vegas, and does peyote.
It is not made clear what insight he receives from the plant, but I think he essentially seems himself as just a facet of the universe. The universe made him this way because the universe decrees that there will be some evil present in it, and Tony happens to be playing that role.
This character's central struggle is to 'correct' himself, to go against his inherent nature, to try and diagnose what is wrong with him. And through endless therapy, nothing really changes. Doctor Melfi too is barking up the wrong tree. She tries to cure him but fails, and only when she comes to terms with the possibility that there is a fundamental evil that cannot be cured, does she find the will to finally close the therapy.
Both Melfi and Tony come to the same conclusion, that there is an inevitability to Tony's evil. He stops feeling guilty I think because he accepts what he is. He is not a mangled creature acting against nature, he is a manifestation of nature that needs to exist, for whatever purpose the higher powers may decree.
"All the while we go about pitying ourselves, whereas we are carried by a great wave"
There are some half sarcastic references to multiple universes. But I think the Finnerton experience also helps Tony understand, that he needs to be who he is so that someone else need not be that person. So in some sense he is both justifying his evil as well as absolving himself of it. Accepting the evil to dissolve the pain it creates in him, again a parallel to what Doctor Melfi does
The ending has generated much debate, but I think there is a simple way to read it.
Christopher Moltisanti expresses the same existential anxiety when he asks 'Where's my arc?'' I think the final scene answers this question. There is no arc, no one has an arc, life just flows along, and it doesn't really matter what happens at the diner scene. At some point the story has to end, and whenever it does end, it will be incomplete. Moltisanti was chasing an illusion in the form of an arc that eventually distanced him from people that loved him, and led to him losing everything.
While the show did not develop this theme with Paulie, earlier on in the show he had expressed some stoic acceptance with his station in life, his slow career progress, his lack of a family, his general character that is made for ridicule. I don't think it is a coincidence that Paulie, with all his so called failings, is the one that survives along with Tony in the end, effectively becoming underboss. Without any overt action on his part, obstacles in his life seem to melt away, and things generally work out for him, even if they do so a bit late. He is even reluctant to take on more responsibility at the end of the show, and the last we see him, he is happily sunning himself. He is also one of the two characters who seemed to be impacted by Sun Tzu's Art of War, though the show played the references for comedy.
Does Paulie do all this intentionally? No, I don't think so. But he also acts without acting, doesn't weigh himself down by ambitions in the same way that others do, leading them to destruction. He feels whatever he needs to feel and then moves on. His stupid attempts to sow discord and participate in the game quickly begin to appear dangerous and he is smart or intuitive or blessed enough to course correct. Tony knows he is the one who told John about the Ginny joke, but even Tony doesn't consider it important enough to kill him for it.