Hemingway entered serious fiction by way of the short story. It was a natural way to begin. His esthetic aims called for a rigorous self-discipline in the presentation of episodes drawn, though always made over, from life. Because he believed, firmly as his own Abruzzian priest, that “you cannot know about it unless you have it,” a number of the stories were based on personal experience, though here again invention of a symbolic kind nearly always entered into the act of composition.
The early discipline in the short story, and it was rarely anything but the hardest kind of discipline, taught Hemingway his craft. He learned how to get the most from the least, how to prune language and avoid waste motion, how to multiply intensities, and how to tell nothing but the truth in a way that always allowed for telling more than the truth.
From the short story he learned wonderfully precise lessons in the use of dialogue for the purposes of exposition. Even the simpler stories showed this power. In the struggle with his materials he learned to keep the poker face of the true artist. Or, if you changed the image to another game, he learned the art of relaying important hints to his partner the reader without revealing all at once the full content of his holdings.
From the short story he gained a skill in the economical transfer of impressions – without special rhetoric or apparent trickery. His deepest trust was placed in the cumulative effect of ostensibly simple, carefully selective statement, with occasional reiteration of key phrases for thematic emphasis.
Like James, he has been rightly called an architect rather than a manipulator, and he himself has said that prose is architecture rather than interior decoration – an esthetic fact which the short story taught him.
Carlos Baker, Hemingway, The Writer as Artist
(Paragraph breaks added to enhance online readability.)