My teacher says that in The Fighting Ground, Jonathan fights a battle inside of himself. What does this mean?

Although
the story only covers twenty-four hours, Jonathan is fighting an internal battle the entire
time. He struggles with issues of patriotic activism contrasted with detached security, courage
and cowardice, and loyalty and betrayal.

Jonathan has heard about the coming
war, so at the first opportunity, he decides to show his patriotism by joining the revolutionary
forces. His father had warned him to stay home and out of the conflict, but Jonathan will not
listen. His desire to serveand to experience adventurewins that particular battle.

Once he gets into a fighting unit and enters the fighting, his zeal cools considerably.
He had assumed that he was a brave person and would act courageously, even nobly, to distinguish
himself. When presented with a choice between advancing and retreating, he chooses the latter
and flees to the relative safety of the woods. Although he does not stay there long, it is long
enough to make him realize that being brave is no simple matter.

Once
involved with the patriot and Hessian forces, he struggles again to be convinced that the
Hessians are simply the evil enemy. Some individual men treat him kindly, so he in turn has
compassion for them, which leads him to try to disobey an officers order. Now he is really torn,
for he cannot determine which decision is right. By the time he returns home, his internal
battle seems to have declared a temporary truce, but he has learned that this battle will
resurface every time he goes off to fight.