How did Ralph Waldo Emerson and Horatio Greenough influence Louis Sullivan’s ideas?

The ideas of American architect Louis Sullivan were significantly shaped by the mid-19th-century writings of the sculptor Horatio Greenough and the essayist Ralph Waldo Emerson.1

These influences contributed to Sullivan’s development of an organic philosophy and aesthetics, which were deeply rooted in the Transcendentalist tradition. Specifically, Sullivan’s inquiries into the nature of architectural style—informed by these thinkers and the evolutionary concepts of Charles Darwin—led to his famous dictum, "form follows function".21

While this phrase is often cited, Sullivan did not intend for it to imply a purely mechanical or utilitarian design. Instead, he believed that architecture should evolve from and express its environment, its structural basis, and its specific function, while also serving to illuminate the human heart. Through these intellectual foundations, Sullivan became a pioneer in considering the relationship between architecture and civilization, moving away from historical eclecticism toward a more creative, organic expression.1