What was the author's purpose in the book The Old Man and the Sea?Ernest Hemingway was the author
Hemingway's purpose is to write both a realistic and allegorical novella that mirrors his own twilight in his writing career.
The novel is very realistic. Hemingway lived in Cuba and was an active fisherman himself. Hemingway was quoted in saying he wanted to write about a real fisherman:
There isn't any symbolism. The sea is the sea. The old man is the old man. The boy is a boy and the fish is a fish. The sharks are sharks, no better, no worse.
Hemingway is a bit too literal here: there's plenty of symbolism. One cannot write a novel about a man and a giant fish without symbolic and allegorical connotations (think Jonah and the whale).
His purpose, allegorically, is to write a parable in which an old man achieves greatness and yet continues to suffer with dignity--much like his own career as a writer. Hemingway wrote Old Man when he was an old man nearing his end (he committed suicide a few years after), and the novella garnered him the Nobel Prize in 1954 for:
"...his mastery of the art of narrative, most recently demonstrated in The Old Man and the Sea, and for the influence that he has exerted on contemporary style."
Just as Santiago suffers against age and the elements, so too was Hemingway suffering against mental health and a literary community that said he was washed up (pun intended).