Why did Neoclassical critics reject Francesco Borromini’s architecture?

Neoclassical critics rejected the architecture of Francesco Borromini primarily because his work stood in direct opposition to the values of the Neoclassical movement, which sought to restore order, reason, and simplicity through the study of Classical antiquity.1

The rejection was driven by several key factors:

• Departure from Anthropomorphism: Neoclassical theory held that architectural proportions should be derived from the human body. Borromini, however, based his designs on complex geometric configurations, a practice that led critics to accuse him of denying the fundamental basis of good architecture.23
• Rejection of Baroque Excess: Neoclassicism emerged as a reaction against the Baroque style, which was viewed as "untruthful" due to its emphasis on illusion, applied ornament, and dynamic, undulating forms—all of which were hallmarks of Borromini’s innovative approach.21
• Non-Orthodox Interpretation of Antiquity: While Borromini studied ancient ruins, he rejected the orthodox compositional motifs of the ancient world in favor of novel, "bizarre" interpretations. Neoclassical architects, by contrast, prioritized archaeologically correct forms and a return to the simplicity of geometric volumes.241

Ultimately, as Neoclassical attitudes gained prominence in the 18th and 19th centuries, Borromini’s radical, experimental style was increasingly despised and largely forgotten until its 20th-century re-evaluation.5