Character Analysis
We don't really see much of Sorel in this book. His role in the story is to give Julien the motivation he needs to escape his peasant lifestyle. How does he do this, you ask? By being an abusive jerk.
He whomps Julien on the head whenever he catches the kid reading. But he also loves to haggle with richer folk and take them for everything they're worth. Even when Monsieur de Rênal offers him a good job for his son, Sorel betrays no signs of happiness. Instead,
[…] he listened with that air of downcast discontent, and absolutely no interest, which the shrewd inhabitants of these mountains understood only too well to drape over themselves. (1.4.3)
This kind of cheap, miserly thinking is exactly the kind of thing Julien wants to escape. That… and the beatings.
Even when his son is on death row, Sorel can't bring himself to say anything encouraging or loving. Instead, he berates his son for bringing shame to the family name (which: fair enough, but what about being a loving dad?):
The old man's reproaches began just as soon as there was no one else to hear him. (2.44.18)
The only way Julien can make him stop is to promise him a bunch of money that will be left over after he (Julien) has been executed. Since this is the only thing Sorel cares about, he's happy to take the deal and leave his son alone.
Sorel's Timeline