What themes are suggested by the following extract from Ernest Hemingway's The Old Man and the Sea?
The shark swung over and the old man saw his eye was not alive and then he swung over once again, wrapping himself in two loops of the rope. The old man knew that he was dead but the shark would not accept it. Then, on his back, with his tail lashing and his jaws clicking, the shark plowed over the water as a speedboat does.