Zhu Xi (; ; October 18, 1130 – April 23, 1200), also known by his courtesy name Yuanhui (or Zhonghui), and self-titled Hui'an, was a Chinese calligrapher, historian, philosopher, politician, and writer of the Song dynasty. He was a Confucian scholar and influential Neo-Confucian in China. His contributions to Chinese philosophy including his editing of and commentaries to the Four Books, which later formed the curriculum of the civil service exam in Imperial China from 1313 to 1905; and his emphasis on the process of the "investigation of things" () and meditation as a method for self cultivation.