ابن سينا و فدك محدودالجهات

Avecenna and the MOHADED AL-JAHAT sphere

The Ptolematic system based its world view on the existence of eight spheres which in turn determined astronomical and physical calculations. The first Islamic philosophers (Farahi and Avecenna) added another sphere which they named MOHADED AL-JAHAT. The arguments of Islamic philosophers rest solely on the latter sphere and the other eight spheres are not discussed. Despite the invalidity of the Ptolematic system following Copernicus theories, nothing was done to reduce the credibility of this ninth sphere hecuse it was never really an integral part of that sysytem as its arguments rested on philosophical evidence and not physical ones. The issue which this article seeks to address is why Islamic Philosophers felt a need to add this sphere and why they became devoted to it. In Islamic Philosophy, this sphere. has two main roles. First, it determines the two principle directions, or in other words, up and down these directions are used to determine the natural position and movement of all objects. Second, this sphere gurantees absolute time and time results from the movment of this sphere. In this article, we analyse the reasons that these philosophers developed this theory and how new theories have affected the MOHADED AL-JAHAT. We show how we can still suhstatiate their views and why and how with new scientific theories, especially in Relitivity, their arguments are no longer credible.