Didactic in the Diction

On page 74 when O'Brien and Sanders are talking about the situation of the men "hearing" things in the mountains, Tim asks Mitchell what the moral of the story is. After a moment of hesitation, Mitchell responds by saying the moral is to "hear the quiet" and "that quiet is your moral." I am not going to lie, I struggled quite a bit with this one, after all how could "quiet" be a moral. However, after I read farther down in the diction , O'Brien goes on to say basically say one cannot extract the literal meaning of the word at the surface without digging down to find the deeper meaning. Here, I think the two men are just as confused as I am when trying to wrap their heads around the moral of the story. Quietness is something that does not face a soldier often in war; however, when it does, (like the men of the anecdote) men have to adapt their mindset and perhaps if they don't they will "hear" the many battle cries of war.