First: The indication of actions: This method is based on the principle of causality, and its foundation is the attribution of actions to their doer. For it has been established in the minds of the intelligent that an action must have a doer, as God Almighty has pointed out in His saying: "Is there any doubt about God, the Creator of the heavens and the earth?" (Abraham / 88). The creation of the heavens and the earth is an action that the intellect observes to know with certainty that there is a doer behind it, which is God Almighty.

Second: Analogy: Al-Mahdi paid great attention to rational analogy as a method of knowledge, and his analysis was critical. He explained the conditions of a correct analogy that leads to truth, and criticized the types of invalid analogies that do not lead to truth, and explained their weaknesses and invalidity.

Correct Analogy: Al-Mahdi defined analogy as "the equality of two things in a ruling" (32). It is not hidden what weakness is in this definition. Analogy is a mental process in which a comparison is made between two matters, and it ends with the equality of the ruling between them, and it is not merely the fact that the two matters are equal in the ruling. The observation of the commonality upon which the equality is based is a fundamental element that Al-Mahdi neglected in his definition.

A correct analogy has a specific scope, and if it exceeds it, it becomes invalid. This scope is determined by the relationship of the analog to the analogized. Analogy between things is not valid with an absolute relationship between them, but rather it is valid only within the scope of the relationship of similarity and the relationship of difference with the presence of resemblance. "Analogy is difficult between two things, but it is possible between two similar things and between two different things if there is a resemblance between them." (33) This is in consideration of the analogy that Al-Mahdi meant, not in consideration of analogy in absolute terms. (34) This analogy that he adopted is taken from the analogy in Usul, which is the establishment of a similar ruling for a known matter in another known matter due to their sharing the cause of the ruling according to the establisher (Abd al-Nabi al-Ahmad Nakri, Dustur al-Ulama: 107). It is closer to the logicians to the representation that Ibn Sina defined as attempting to rule on something with a ruling that exists in its similar. (35) It is closer to the analogy that he defined as a statement composed of statements, if the premises included in it are accepted, then another statement necessarily follows from it by itself. (See: Al-Isharat wa al-Tanbihat: 1/207, Risala fi anna al-Shari'a la tuthbat bi al-'aql: Ibn Tumart, 1/3)