Fushujisho(不守自性)means that Shinnyo(真如)loses its essence. Zuien(随縁), consequently, means that Shinnyo presents itself as the creation of purity and dirt. The first one, who used this concept was Hozo, a master of chinese Kegon master. He did it for ranking the other schools and doctrines, to which he attributed lesser values under the Kegon school. Kuhai, however, the first patriarch of Japanese shingon school, gave to this concept an interpretation for summerizing the Kegon philosophy in his works. I think, that his heterodox use of this concept is based on the alterd interpretation, as it is found in Shaku-makaen-ron(釈摩訶衍論), on which he set much value. Hozo always used this concept contrastively as a pair together with the concept of Shinnyo, which he described as presenting itself, while retaining its essence (Zuien-Fushitujisho随縁不失自性). The author of Shaku-makaen-ron, however, emphasized only Fushujisho-zuien. His motivation was, probably, to claim that Kegon's truth must be confirmed by religious practice. His intention was not a denial of the Kegon school, but a supplement or a perfection of it. Kuukai had probably understood the intention of the Shaku-makaen-ron's author. He, however, adopted only the framework of religious practice for founding his own system, the new shingon school. He therefore also descriminated the Kegon school by explaining that it reduces itself to the concept of Fushujisho-zuien.
