Although they have prepared the machine gun, the group does not have to shoot the Fascist cavalry who pass them by undetected. Agustin, who is sweating profusely, wants to attack but Jordan holds him back. Later, Agustin explains that holding back from killing a man is the hardest thing in the world to resist and Jordan then reflects that the Spanish as a people still maintain the old pagan bloodlust just underneath the surface: "Killing is something one must do, but ours are different from theirs" (287). Anselmo isn't like this, however, and Jordan thinks: "He is a Christian, he thinks, something very rare in Catholic countries" (287).
The desire to kill is even stronger than the sexual urge for some, Hemingway maintains. Agustin compares the intense feeling he experienced while resisting the impulse to kill the cavalry to a corralled mare waiting for the stallion. And, Hemingway posits, it is this primeval urge that keeps the Republican Cause in motion. The Spanish are the people who instigated the Inquisition, after all, and that thirst for blood hasn't dissipated over time. It has merely changed form. Thus, man can adopt religious doctrine or political outrage to quench his innate hunger and desire for carnage.