What's meant here by " his serving as second proves very little about what he thought of the quarrel"?

Question

In "The Chief Mourner of Marne" by G. K. Chesterton, Mr. Outram was talking to Father Brown about an old duel between Mr. James Mair, whose second was Mr. Outram himself, and his cousin Maurice Mair, whose second was Hugo Romaine, saying:

Hugo Romaine was his second; the great actor, you know. Maurice was mad on acting and had taken up Romaine (who was then a rising but still a struggling man), and financed the fellow and his ventures in return for taking lessons from the professional in his own hobby of amateur acting. But Romaine was then, I suppose, practically dependent on his rich friend; though he’s richer now than any aristocrat. So his serving as second proves very little about what he thought of the quarrel. They fought in the English fashion, with only one second apiece; I wanted at least to have a surgeon, but Maurice boisterously refused it, saying the fewer people who knew, the better; and at the worst we could immediately get help.

What's meant here by this statement?

I mean what's the link between serving as second and his thoughts of the quarrel?

Does he mean that "because he was dependant on his friend, he was bound to serve as his second anyhow?"

Answer 1

It carries the implication that if Romaine had not acted as his second, even if he thought Maurice ought not to fight the duel, Maurice might have cut off the money, which he was dependent on. (This could be Maurice exploiting his dependence, or it could be Maurice regarding his acting as a second as part of their friendship, and so refusing is showing that Romaine is willing to take from his friend but not to give back.)

This stems from the context. In other contexts, that sentence might mean that he hoped to reconcile the duelists before the duel -- the traditional first step in a duel was an attempt by the seconds to get them to call it off, though it was often a hollow formality -- or to assist with any injury, and thus be willing to act as a second in a duel he thought wrong.

Answer 2

According to general Outram, Maurice Marne had been taking acting lessons with Hugo Romaine. At that time, Romaine was not yet a celebrated actor, so giving acting lessons was a very welcome source of income. The general says, "Romaine was then, I suppose, practically dependent on his rich friend." In other words, at that time, the acting lessons he gave Maurice Marne were a more important source of income than his own acting career.

A second in a duel is usually chosen among trusted friends, but the relationship between Hugo Romaine and Maurice Marne was of a completely different nature from the general's point of view (as explained above). Hence, from the general's point of view, Romaine served as Maurice's second because he depended on him financially, so it is impossible to say with certainty that he supported Maurice Marne's jealousy..