brothers
Usually something like that is symptomatic of a deeper problem, specfically that I don't know the character well enough to be writing about him or her. This time the character finally clicked (just yesterday) because I realized that the key relationship in his life was not so much his father, but his brother. Does anybody remember Paul Savard, the doctor who worked with Hannah at the Almshouse in Manhattan? This is his half brother. That's all I'm going to tell you about him at this point, beyond the fact that his formal first name is Jean-Batiste.
The key to this person is his relationship to his father and brother, and the key to that I found encapsulated in the story of Damon and Pythias -- who weren't brothers, but close friends (this summary from Bartleby):
In a Greek legend, two friends who were enormously loyal to each other. When the tyrannical ruler of their city condemned Pythias to death, Pythias pleaded for time to go home and put his affairs in order. Damon agreed to stay and die in place of Pythias if Pythias did not return by the time of the execution. Pythias was delayed, and Damon prepared to be executed. Pythias arrived just in time to save Damon. The ruler was so impressed by their friendship that he let them both live. Damon and Pythias symbolize devotion between friends.This struck me, when I came across it, as a more complex and interesting version of the Prodigal Son, and it patterns exactly to what had been cooking in the back of my brain about the Savard family (father, and two sons). I have generally stayed away from examining the relationship between brothers, because it is such a challenge for me to understand that particular kind of connection. This time, it can't be avoided and thus my reluctance or fear was getting in the way. Not that words will flow like water now that I've figured out what's going on, but they will move.