What is the significane of Sanders' dicussion with Dobbins about a moral in connection with cutting off his thumb? What does the moral suggest? What might he mean?

The significance of Sanders explanation that the thumb had a moral behind it...... was the fact that he believed the war had no moral. He is questioned throughout the story as to what the moral was, but he only ever answered, "There it is man." Thus, the thumb is a reminder that Sanders saw the thumb as the only reason they were there. He didn't see a point to the destruction or the fighting, so I believe the thumb reminded him of the futility under which they were fighting.