Which architect is credited with the phrase "form follows function"?

The phrase "form follows function" is widely attributed to Louis Sullivan, an influential American architect. This concept emphasizes that the shape and design of a building should primarily be based upon its intended purpose or function. Sullivan believed that architectural design should be driven by the practical needs of the user rather than purely aesthetic considerations.

This principle became foundational in modernist architecture, as it suggests that aesthetics should emerge naturally from utility. Sullivan's approach influenced many architects and movements in the 20th century, including the work of Frank Lloyd Wright, who was his protégé and later established his own distinct architectural philosophy.

Understanding this context sheds light on why the correct attribution is with Louis Sullivan, as his doctrine laid the groundwork for modern architectural practices where simplicity and functionality are prioritized in design.