Key themes present in the works of Ernest Hemingway include existentialism, disillusionment, and the exploration of human experiences. His writing often reflects themes of courtship and the impact of war on individuals, as seen in novels like "A Farewell to Arms" and "The Sun Also Rises." Hemingway's characteristic prose style, known for its brevity and simplicity, conveys deep emotional and psychological struggles. The recurring motif of the “Hemingway code hero” embodies resilience and the search for meaning in a chaotic world, further solidifying his influence on modern literature.