Perennial philosophy is an essential part of all religions and is universal. The followers of this School of thought believe that this knowledge is accessible to the witnessed intellect and since it is Available in all traditions and religions, the access to it is only possible through the means whose Roots are related to the eternal source.The Moslem followers of perennial philosophy consider this tradition as the same first Tradition in which there has never been any changes.The pure methaphysic is hidden in perennial philosophy and from the view point of perennial philosophy, it is the same knowledge which purifies.As Dr. Nasr states, this is the same mysticism which exists in the heart of perennial philosophy.