The marlin is the giant, 18-foot fish that battles with Santiago
in the middle of the ocean for three days and three nights. Although Santiago hooks the marlin on his first afternoon at sea, the marlin refuses to come to the surface and instead pulls Santiago farther and farther from land. Santiago admires the marlin's beauty and endurance, and considers it a "noble" adversary, telling the fish repeatedly that though he loves it, he must kill it. Ultimately, the marlin is presented as Santiago's worthy opponent. Struggling against such an opponent brings out the best in an individual—courage, endurance, and love. At the same time, because Santiago comes to see the marlin as an alter-ego—he identifies the marlin as male and imagines the fish is old—the marlin comes to represent Santiago himself as well. In other words, Santiago's struggle with the marlin is in fact a struggle with himself. It is not a struggle of strength but rather of endurance, and a refusal to accept defeat. Santiago's struggle with the marlin is a struggle to face and overcome his own weaknesses as much as it is a struggle to subdue the great fish. In the process, by refusing to give in to the fish or the weakness of his mind and body, Santiago transcends those weaknesses.