The term varies in its application according to the different aspects of a single meaning. Hearing, as a path to knowledge, is the path of revelation. The term may be used for the content of revelation, which consists of truths. It may also be used for the method by which these truths are transmitted to us. And it may be used for the means by which we perceive them.

The domain of hearing is a vast one, encompassing all the truths of religion, as revelation has informed us of all these truths, either in general or in detail. However, some of these truths are accessible to our intellects, such as the existence of God, His oneness, and His perfection. Others, we can never reach except through the definition of revelation, such as the matters of the afterlife and all the rules of Sharia related to conduct. There is no path to knowing these except through religious transmission. Therefore, the term "hearing" is predominantly applied to them. Ibn Tumart said, speaking of the religious basis: "It must be established either by reason or by hearing. And establishing it by reason is false, for reason only allows for possibility and the conflict of two possibilities. Possibility and the conflict of two possibilities are doubt." Doubt cannot establish anything, for it is false. It is impossible to take truth from falsehood. So, if its establishment by reason is invalidated, only hearing remains.

Ibn Tumart did not elaborate further on the reality of hearing or in detail on how it yields knowledge. However, he did elaborate on its method of transmission, which is through continuous narration (tawatur), and on the path to its correct understanding, which is the path adopted by the scholars of Usul. We will postpone the discussion of these two matters to the views of the Usul scholars.

Conditions and Obstacles of Knowledge: The aforementioned paths do not lead to their goals in achieving sound perception unless they are accompanied by material and moral circumstances. The former are conducive to positive assistance, and the latter are due to the removal of hindering obstacles. The former have been expressed as "conditions," and the latter as "obstacles."

Ibn Tumart, Risala fi al-Salat: (73) See page (74) and what follows. 1684