Opening the Novel
Even though Hemingway does unfold his novel without a lot of description, he does open the novel with description. Hemingway writes:
In the late summer of that year we lived in a house in a village that looked across the river and the plain to the mountains. In the bed of the river there were pebbles and boulders, dry and white in the sun, and the water was clear and swiftly moving and blue in the channels. Troops went by the house and down the road and the dust they raised powdered the leaves of the trees. The trunks of the trees too were dusty and the leaves fell early that year and we saw the troops marching along the road and the dust rising and leaves, stirred by the breeze, falling and the soldiers marching and afterward the road bare and white except for the leaves. (2)
There are three things to note about this passage. First, note the simplicity of words. By avoiding lengthy descriptions and unnecessary adjectives and adverbs, Hemingway is able to put, very saliently, in our minds the image he wants us to see.
Second, note the contrast between the description in the first two sentences and the second two sentences. In the first two sentences, Hemingway describes a serene scene. One where it's filled with beauty and life. In the second two sentences, however, the troops, marching because of the war do more than just disturb the dirt road. They also brought about the death of nature in the area because the "...trunks of the trees were too dusty and the leaves fell early that year..." His description isn't just describing the scene, but it's setting the stage for the novel.
That brings me to the third point. Astute readers will note that this opening paragraph is actually an allegory for Hemingway's novel. The novel appears like it will be a love story, but then turns into something more tragic. The love between Frederic and Catherine becomes like the leaves — destroyed by the presence of the war in the background. Rather than describe the war in detail, he treats it the same way he does the troops in the opening paragraph — it's anonymous, made up of different bodies and places strung together, yet powerful enough to lay beauty crossing its path to death.