What is Hemingway's philosophy in this book? thank you!

Hemingway believed that no matter what comes of our efforts, our nobility comes from the way we perform (with honor and dignity) rather than whether we win (achieve whatever it is we set out to do).  Both Santiage and the fish lose in this book; the fish is caught and loses its life only to be devoured by sharks before it is brought to land; Santiago lands the fish after exhausting efforts on his part, only to lose his catch before brining it to shore.  Were all their efforts wasted because of the "sharks" in this world?  No.  Since the results are always uncertain, the only thing that counts, in Heminway's philosophy, is that we struggle nobily, without complaining, that we follow the rules of the "fight."  Since we cannot control the outcome, we can only  be judged by the effort.