What's the good of mentioning "If he could help it" here?

Question

In "The Chief Mourner of Marne" by G. K. Chesterton, Mr. Mallow is searching for Father Brown to consult him about very serious problem, and finds him at a friend's house.

He entered somewhat abruptly to find Father Brown sitting on the floor with a serious expression, and attempting to pin the somewhat florid hat belonging to a wax doll on to the head of a teddy bear.

Mallow felt a faint sense of incongruity; but he was far too full of his problem to put off the conversation if he could help it. He was staggering from a sort of setback in a subconscious process that had been going on for some time.

I found that can help it mean can avoid or stop himself from doing it, but the author already said that he was so full of his problem that he can't put off the conversation, so what's the good of mentioning If he could help it?

Answer 1

'If one can help it' is an expression akin to 'if it is in one's power'. In the passage, He was concerned about his problem and, if he could help it (if it were in his power), he wanted to avoid a postponment of the meeting, even thought Father Brown appeared too busy or preoccupied at that time.

Answer 2

I suppose the meaning of the paragraph would not be much different if the sentence was simply, "Mallow felt a faint sense of incongruity; but he was far too full of his problem to put off the conversation."

But often a writer will say something in two different ways, or explicitly state something that one could infer from the context, just to be clear or for emphasis.

Like suppose I said, "Bob is lazy and refuses to get a job". If I just said, "Bob refuses to get a job", you would probably conclude that he is lazy, so one could argue that saying he is lazy is redundant. But it is fair to say it anyway for emphasis. And it might prevent ambiguity -- someone might think that there is some reason why Bob refuses to get a job other than laziness. Like, who knows, maybe he feels he must stay home to take care of his sick grandmother or whatever.

Same thing here. You might guess that Mallow is so anxious to get to this conversation that OF COURSE he can't help it. Chesterton probably added that for emphasis.