<P> Alhazen was a Muslim, however, it is not certain to which school of Islam, he belonged . As a Sunni, he may have been either a follower of the Ash'ari school, or a follower of the Mu'tazili school . Sabra (1978) even suggested he might have been an adherent of Shia Islam . </P> <P> Alhazen wrote a work on Islamic theology in which he discussed prophethood and developed a system of philosophical criteria to discern its false claimants in his time . He also wrote a treatise entitled Finding the Direction of Qibla by Calculation in which he discussed finding the Qibla, where prayers (salat) are directed towards, mathematically . </P> <P> There are occasional references to theology or religious sentiment in his technical works, e.g. in Doubts Concerning Ptolemy: </P> <P> Truth is sought for its own sake...Finding the truth is difficult, and the road to it is rough . For the truths are plunged in obscurity...God, however, has not preserved the scientist from error and has not safeguarded science from shortcomings and faults . If this had been the case, scientists would not have disagreed upon any point of science...</P>

The duty of the man who investigates the writings of scientists