For Hemingway, God did not exist, and the universe is indifferent. The resulting world is hostile and muddled, and without God and faith, moral values are also meaningless. War is an example of this.
Hemingway's theory of omission is widely referred to as the "iceberg principle." By omitting certain parts of a story, he actually strengthens that story. The writer must be conscious of these omissions and be writing true enough in order for the reader to sense the omitted parts. When the reader senses the omitted parts, a greater perception and understanding for the story can be achieved.
Symbolism
Hemingway disliked discussions regarding the symbolism in his works. The "iceberg principle," however, by its very nature, invites symbolic interpretations and Hemingway acknowledged this in his own subtle way.
No good writer ever prepared his symbols ahead of time and wrote his book about them, but out of a good book which is true to life symbols may arise and be profitably explored if not over-emphasized.
