He was a Confucian scholar with the pen name Ungok active between the late Goryeo dynasty and early Joseon dynasty. He was the son of Won Yun-jeok who served as Jong (official) at the Jongbusi (Royal Family Management Office). He further is the ancestor of the Wonju Won family line. He passed Jinsasi (the basic civil service examination), but he did not try Gwageo (higher civil service examination) as he saw that political circles were disrupted towards the end of the Goryeo dynasty. Hewas even ashamed of having passed the Jinsasi examination, and went into hiding at Chiak Mountain to be engaged in farming and support his parents.
He further was associated with then great Confucians. Lee Saek, Lee Sung-in and Giljae, and concentrated on academic studies. Won Cheon-seok once taught King Taejong while he was still a Prince. When King Taejong ascended to the throne, he called him to serve an office - in vain.
The King then personally visited Won Cheon-seok, who avoided meeting him. Afterwards, he was forced to enter the Palace upon the special instruction of King Taejong who was then retired, but he again turned down his request to support him. He has handed down one piece of Sijo (poem) reminiscent of the Goryeo dynasty. He wrote and handed down to his descendants five history books on the times spanning the end of the Goryeo dynasty and the start of the Jeseon dynasty. However, since much of these contents contradicted state affairs, his great grandchildren are said to have burned them. As Won Cheon-seok (Ungok) was highly revered for his fidelity to principles, Confucian scholars in the Wonju district established a private school named Chilbong in memory of him, paid tribute to him and held a memorial service for him.