The aim of scholastic theology is to preserve the purity of orthodox belief from heretical innovation: “God raised up a school of theologians and inspired them with the desire to defend orthodoxy by means of a system of proofs adapted to unveil the devices of the heretics and to foil the attacks which they made on the doctrines established by tradition” (Al-Ghazali: _Confessions_). Aristotle himself was an unbeliever using arguments he should not, but, in spite of his errors, his teaching as expounded by al-Farabi and Ibn Sina is the system of thought which comes nearest to Islam (id.). Because of its unavoidable difficulties and the grave errors contained in Aristotle and his Arabic commentators men are not to be encouraged to read philosophy (id.). There are three different worlds or planes of existence (i.) the _`alam al-mulk_ is that in which existence is apparent to the senses, the world made known by perception, and this is in a state of constant change; (ii.) the _`alam al-malakut_, the changeless and eternal world of reality established by God’s decree, of which the world of perception is but the reflexion; (iii.) and the _`alam al-jarabut_ or intermediate state, which properly belongs to the world of reality, but seems to be in the plane of perception. In this intermediate state is the human soul, which belongs to the plane of reality, though apparently projected into the perceptible plane to which it does not belong, and then returns to reality. The pen, tablet, etc., mentioned in the Qur´an are not mere allegories; they belong to the world of reality, and so are something other than what we see in this world of perception. These three worlds or planes are not separate in time or space, they are rather to be considered as modes of existence.