Chinese philosopher who greatly influenced the development of the idealist school of Neo-Confucianism (see Confucianism). Shao Yong's mathematical ideas also influenced the 18th-century European philosopher Gottfried Wilhelm Leibniz in the development of a binary arithmetical system—i.e., one based on only two digits.

Originally a Daoist, Shao refused all offers of government office, preferring to while away the hours in a humble hermitage outside Luoyang, conversing with friends and engaging in mystical speculation. He became interested in Confucianism through his study of the great Confucian Classic and work of divination, the Yijing (“Classic of Changes”). Through the Yijing, Shao developed his theories that numbers are the basis of all existence. To him, the spirit that underlies all things could be comprehended if one understood the division of the different elements into numbers. But unlike most previous Chinese numerologists, who usually preferred the numbers two or five, Shao believed the key to the world hinged on the number four; thus the universe is divided into four sections (Sun, Moon, stars, and zodiac), the body into four sense organs (eye, ear, nose, and mouth), and the Earth into four substances (fire, water, earth, and stone). In a similar way, all ideas have four manifestations, all actions four choices, and so forth.

Although this complicated system was outside the basic concerns of Confucianism and exercised only a peripheral influence on the development of Chinese thought, what was important was the basic theory behind the system; there is an underlying unity to existence, which can be grasped by the superior man who understands its basic principles. The idea that the underlying principle behind the unity of the universe exists in the human mind as much as in the universe was the basis of the idealist school of Neo-Confucianism. Moreover, Shao brought into Confucianism the Buddhist idea that history consists of series of repeating cycles. These cycles, known to Buddhists as kalpas, were called yuan by Shao and reduced from an astronomical length to a comprehensible duration of 129,600 years. Shao's theory was later accepted by all branches of Neo-Confucianism and made part of the official state ideology by the 12th-century Song scholar Zhu Xi.