Much of the popular literature on nafs, however, is focused on the Sufi conceptions of the term. According to the Sufi philosophies, the nafs in its unrefined state is "the ego", which they consider to be the lowest dimension of a person's inward existence — his animal and Satanic nature.[1] Nafs is an important concept in the Islamic tradition, especially within Sufism and the discipline of gnosis (irfan) in Shia Islam.