"I'm a sinner, I know, doubly a sinner, by Divine Law and by Stella's human love. There's no doubt of that, and tomorrow I'll go and confess to Father Pirrone." (1.68)
Fabrizio has a bit of a Don Draper thing going on, since he knows he's doing something wrong when he cheats on his wife, but he does it anyway. He also figures that he can make it all better by confessing to his priest. At the end of the day, though, there's definitely some deep dissatisfaction at play here: both with his wife and with his life.
The soul of the Prince reached toward [the stars], toward the intangible, the unattainable, which gave joy without laying claim to anything in return. (2.84)
Prince Fabrizio is an amateur astronomer who loves gazing at the stars. As a guy who has always gotten what he wants, he truly desires something that is forever beyond his reach. It makes sense then, that he would reach toward the stars, since he knows that he'll never get anywhere near them.
Who worries about dowries for the Pleiades, a political career for Sirius, matrimonial joy for Vega? (2.84)
Whether it's his dog Bendicò or the stars in the sky, Fabrizio admires anything—living or dead—that doesn't have to deal with petty human concerns. When he thinks of the constellations in the sky, for example, he knows that the star Sirius never needs to worry about who's going to marry his daughter. It's this kind of search for peace that eventually leads Fabrizio to take comfort in the moment of his death.
[Now] he knew who had been killed at Donnafugata, at a hundred other places, in the course of that night of dirty wind: a newborn babe: good faith: just the very child who should have been cared for most. (3.36)
Fabrizio wants to be hopeful for the future of Sicily, but it's hard when he realizes that the vote for joining Italy has been rigged. Every time the poor guy has hope for the future, the world has a way of letting him down.
He sat down a little among them; there instead of the name of the Queen of Heaven being taken in vain, the air was turgid with commonplaces. (6.28)
Fabrizio is bored by all the aristocrats he tends to hang out with. It's not like he wants to go in the opposite direction and hang with a bunch of roughnecks, but things can get really boring when the only people you hang out with are too polite to ever say anything interesting.
Don Fabrizio sighed. When would she decide to give him an appointment less ephemeral, far from carcasses and blood, in her own region of perennial certitude? (6.76)
Whenever he needs true spiritual fulfillment, Fabrizio looks to the stars and asks for their guidance. This isn't the same thing as asking God for help, because The Prince could go to Father Pirrone for that. This is instead a more private type of faith that Fabrizio shows when he talks directly to the constellation of Venus, who never judges him the way that a Christian god would.
Don Fabrizio had always known that sensation. For a dozen years or so he had been feeling as if the vital fluid, the faculty of existing, like itself in fact and perhaps even the will to go on living, were ebbing out of him slowly but steadily, as grains of sand cluster and then line up one by one, unhurried, unceasing, before the narrow neck of an hourglass. (7.1)
Fabrizio can feel his life slipping away from him with every day he gets older. One of the things that makes this feeling so unsatisfying is how slowly things seem to be slipping away. If it were all over and done with quickly, he could deal with it. But the fall of his social class is something that happens by inches more than all at once.
Sometimes he was surprised that the vital reservoir could still contain anything at all after all those years of loss" (7.3).
Fabrizio has always had what he wanted out of life. But on the other hand, that means he has also had a lot to lose. And lose he has. By the time he's old, he has far less than he started out with, both in terms of relatives and in terms of prestige.
And the pains, the boredom, how long had they been? Useless to try to make himself count those; all of the rest: seventy years. (7.25)
In his 73 years of life, Fabrizio figures that he has spent two or three of them actually living. The rest he's spent submerged in a life of boredom and habit, which is definitely not a recipe for personal fulfillment.
Still she could feel nothing; the inner emptiness was complete, but she did sense an unpleasant atmosphere emanating from the heap of fur. (8.55)
Concetta knows that there's something weird about Bendicò, apart from the fact that he's a stuffed dog who died decades ago. He's a reminder of a bygone age, a time when her father was still alive and her family lived in lavish palaces. Those days are long over, though, so it's no wonder she finds the dog unpleasant as a reminder of them.