With the feeling of I-ness the innate power of the Absolute, so to speak, pulled itself together; in other words concentrated on one point. Thus the all-pervading radiance formed its center, the Center which is the divine Spirit or the Nur, in Sufi terms called Arwah. This central light then divided existence into two forms, light and darkness. In point of fact, there is no such thing as darkness, there has never been darkness; it is only less light compared with more light. This light and darkness formed an Akasha or Asman, an accommodation, a mold; and the phenomenon of light and shadow working through this mold furthered the manifestation into a great many accommodations, Asmans or Akashas, one within the other. Every step manifestation has taken has resulted in a variety of forms made by the different substances which are produced during the process of spirit turning into matter. The working of this process has been according to the law of vibration, which is the secret of motion; and it is the plane of the definite forms of nature which is called Asman in Sufi terminology.