Here, one again encounters terminological confusion: for the Sufis influenced by Neoplatonism, a "higher" part of Nafs is equated to the Aql or intellect (called Nafs-I-Natiqa) or "rational soul" and is the central active agent in spiritual battle: Ruh or spirit, notwithstanding its name, is rather passive in this stage. In short, cleansing of the Qalb or heart is a necessary spiritual discipline for travellers on the Sufi path. The term for this process is Tazkiah-I-Qalb and the aim is the erasure of everything that stands in the way of purifying God's love or Ishq. [citation needed]