Why are Edgar Allan Poe's critical and doctrinal essays important?

Edgar Allan Poe’s critical and doctrinal essays are significant for their profound influence on literary theory, craftsmanship, and the development of the short story as a serious art form.12

As a critic, Poe emphasized the importance of structure, meter, and correctness of language. His most enduring contribution to literary theory is the concept of "unity of effect," which he argued should be the primary design of a short story. He posited that every word in a composition should contribute to a single, pre-established design, demanding artistic diligence and seriousness from the writer.12

Beyond his technical influence, Poe’s nonfictional prose—including his writings on poetics, cosmology, and dreams—exerted an immense impact on European literature. His essays served as a master model for French poets such as Charles Baudelaire and Stéphane Mallarmé, and provided the foundational principles for French Symbolism and the theory of pure poetry. Ultimately, these essays are valued for their "dazzling intuitions," which many scholars now consider as central to his legacy as his fiction and poetry.31