In Chapter 18, Jordan dwells extensively on topics of war and violence, specifically meditating on the feeling of fear. In a scene describing the emotions one experiences during battle, Jordan uses personification to better characterize the automated, desperate actions of a soldier:
In all that, in the fear that dries your mouth and your throat, in the smashed plaster dust and the sudden panic of a wall falling, collapsing in the flash and roar of a shell burst, clearing the gun,
dragging those away who had been serving it, lying face downward and covered with rubble, your head behind the shield working on a stoppage, getting the broken case out, straightening the belt again, you now lying straight behind the shield, the gun searching the roadside again; you did the thing there was to do and knew that you were right.
Jordan chooses to personify the guns in this story, according them more agency in a wartime scenario than the soldiers themselves. Through the use of this device, Hemingway demonstrates the fact that guns often seem to control the soldiers in war, rather than vice versa. This instance of figurative language helps characterize soldiers' cognitive dissonance: the emotional disconnect one must have from one's own actions, in order to kill another person in cold blood.
In Chapter 43, Jordan and Maria see their love tested on the battlefield, engaged in a conflict that might see them both killed before the day's end. Despite this, and despite all of the chaos of the battlefield, Jordan still feels drawn to Maria—and she to him. Hemingway expresses this relationship through the use of personification:
He had never thought that you could know that there was a woman if there was battle; nor that any part of you could know it, or respond to it; nor that if there was a woman that she should have breasts small, round and tight against you through a shirt; nor that they, the breasts, could know about the two of them in battle. But it was true and he thought, good. That's good.
Maria's breasts "know," or have intellectual awareness of her and Jordan's relationship. Jordan expresses surprise that he still feels the same pull of attraction to Maria during the battle, having assumed that desire and warfare could not exist in the same space or mindset. This signifies both their unity as a couple and Jordan's increasing contentment with himself (i.e., allowing multiple parts of himself to coexist, and being happy with those parts).