Neoplatonism strongly influenced the development of Sufism. Neoplatonism, as developed by Plotinus conceives God to be the source and goal of everything. Islam qua institution is closed to all critical and philosophical thought, but Sufism enjoys a more liberal and critical approach. It is probable that the translations of Plotinus have provided the necessary philosophical ground for Sufism. An examination of both Sufism and Neoplatonism reveals close similarities with regard to the nature of God, the soul, the body, concepts such as goodness, evil and beauty, death and life, and creation.
Islamic thought was influenced by Greek philosophy, especially the ideas of Aristotle and Plato. Sufism is a sect of Islam which has rather a different way of thought. "Sufi" is applied to Muslim mystics who, as a means of achieving union with Allah, adopted ascetic practices including wearing a garment made of coarse wool called "sf". The term "sufism" comes from "sf" meaning the person, who wears "sf". But in the course of time, sufi has come to designate all Muslim believers in mystic union.
In the roots of sufi philosophy there are influences other than neoplatonist philosophy. Ascetic practices within the sufi philosophy are associated with Buddhism. The notion of purification (cleaning one' s soul from all evil things and trying to reach Nirvana and to become immortal in Nirvana) plays an important role in Buddhism. The same idea shows itself in the belief of "vuslat" (communion with God) in Sufi philosophy.
Sufism was also influenced by Orpheus and related beliefs, and consequently by Pythagoras and his teachings, because Pythagoras was closely interested in Orpheus beliefs. Orpheus was a poet who lived in Anatolia in the 6th and 7th centuries BC. He was believed to have divine characteristics such as being able to influence wild animals with his music. He believed that the human soul can reach the highest level only by refining itself from all passions and worldly possessions. Soul travels from body to body in order to purify itself from its sins, disabilities, and guilts, and only after passing all these levels can it reach to its highest level, to its exalted spot. Pythagoras adopted Orpheus beliefs about soul, and integrated it with his own ideas. Later, the Neopythagoreans regarded Pythagoras as the source of divinely revealed knowledge. They accepted as truth whatever appealed to them in the writings of Plato, Aristotle, and the Stoics