Borromini.

An altogether more tempestuous spirit and highly imaginative genius animated the architectural visions of Francesco Borromini (1599–1667), the architect of a number of churches in and around Rome in the mid-seventeenth century. Unlike the amiable Bernini, Borromini was a loner who was quick to take offense and who eventually ended his life in suicide. While his competitor Bernini reveled in interiors filled with opulent displays of gold, colored marbles, and sculpture, Borromini's designs usually called for stark white, highlighted only by touches of gilt. Into these spaces he poured strange symmetries, curving walls and entablatures, and concave pediments—in short, shapes that had never been seen before in such close juxta-position. Trained as a sculptor like Michelangelo and Bernini, he obsessed over small details in his designs, treating buildings as if they were sculptural forms. His plans almost always reveal...