The treatises, which are in contact with almost every field of science, look like an encyclopedia in terms of their showing the life of thought in the period of time when they came into being and of their systematizing all avaible materials. The Treatises, which formed the first known encyclopedia in the Islamic world, present the Picture of the intellectual life in the tenth century, especially the aspect of thought. The Treatises, the first book to collect all sub-disciplines of philosophy between two covers, are also the first initiative with the aim of teaching community with the philosophic and scientific methods