In The Old Man and the Sea, there are noticeably several symbols, such as the fish (especially), his dreams of lions, the cross, and Joe DiMaggio. Out of all these, excluding the fish, which would plays the most important role/why?
(From my perspective, I think DiMaggio would be the most important symbol in this particular story. Although DiMaggio never appears in the novel, he plays a significant role nonetheless. Santiago worships him as a model of strength and commitment, and his thoughts turn toward DiMaggio whenever he needs to reassure himself of his own strength.)
Certainly, a strong argument can be made for the symbolism of Joe DiMaggio as Santiago exhibits the endurance of pain as well as did the famous baseball player who suffered from bone spurs in his feet. Likewise, arguments can be made for the other symbols because Santiago, the consummate code hero, exhibits all of the characteristic necessary for Hemingway's man; but, unlike other protagonists, he has already attained all of these requisite attributes. For, he is
a man who lives correctly, following the ideals of honor, courage, and endurance in a world that is sometimes chaotic, often stressful, and always painful.
Perhaps, then, the only remaining ideal Santiago has that he yet strives for is symbolized in the dream of the lions. This is the symbol of his imagination, that part of man which keeps him alive, that part of man which enables him to endure. In the Great Gatsby, for example, narrator Nick Carraway expresses this ideal by looking to the West:
Gatsby believed in ...the orgastic future that year by year recedes before us. It eluded us then, but that's no matter--tomorrow we will run faster, stretch out our arms farther...And one fine morning---
At the end of Hemingway's novel, old Santiago is debilitated and impoverished. Although his physical situation is dire, he is not destroyed spiritually because he restores his mental resilience while he sleeps on his face as he did when a boy and dreams of the lions, his "orgastic future" for which he will yet strive. Hopefully, "one fine morning" will come for Santiago. It is this dream of the lions, the exercise of his imagination, which gives Santiago the will to endure and persevere.