This article covers the conversations between Islamic philosophy and Jewish philosophy, and mutual influence on each other in response to questions and challenges brought into wide circulation through Aristotelianism, Neo-platonism, and the Kalam, focusing especially on the period from 800–1400 CE. Freedom versus Fatalism and the Kalam A century after the Qur'an was written, numerous religious schisms arose in Islam. Skeptics sought to investigate the doctrines of the Qur'an, which until then had been accepted as divine revelation. The first independent protest was that of the Qadar ("Destiny"), whose partisans affirmed the freedom of the will, in contrast with the Jabarites (jabar, force, constraint), who maintained the traditional belief in fatalism. In the second century of the Hijrah, a schism arose in the theological schools of Basra, over which Hasan al-Basri presided. A pupil, Wasil ibn Ata, who was expelled from the school because his answers were contrary to tradition, proclaimed himself leader of a new school, and systematized all the radical opinions of preceding sects, particularly those of the Kadarites. This new school or sect was called Mutazilites (from 'tazala, to separate oneself, to dissent). The sect had three principal dogmas: (1) God is an absolute unity, and no attribute can be ascribed to Him. (2) Man is a free agent. Because of these two principles the Mutazilites designate themselves the "AsḦab al-'Adl w'al TauḦid" (The Partisans of Justice and Unity). (3) All knowledge necessary for the salvation of man emanates from his reason; he could acquire knowledge before as well as after Revelation, by the sole light of reason—a fact which, therefore, makes knowledge obligatory upon all men and women, at all times, and in all places. The Mutazilites, compelled to defend their principles against the orthodox Islamic faith, looked for support to the doctrines of philosophy, and thus founded a rational theology, which they designated " 'Ilm-al-Kalam"; and those professing it were called Motekallamin. This appellation, originally designating the Mutazilites, soon became the common name for all seeking philosophical demonstration in confirmation of religious principles. The first Motekallamin had to combat both the orthodox and the infidel parties, between whom they occupied the middle ground; but the efforts of subsequent generations were entirely concentrated against the philosophers. The later Motekallamin formed a school known as Ash'arism, which regarded itself as the champion of orthodoxy, and references by the later philosophers to "Motekallamin" (theologians) should usually be taken