Because no imaginable society can continue to exist without...

Because no imaginable society can continue to exist without a series of rules and norms that all or the majority of the people follow, respect, and sanctify. For instance, if in a transaction between two people neither the buyer nor seller is bound by the effects and conditions of the transaction, no sane person would be found performing such a deal.

Equally, there are innumerable other issues with which social humankind organizes its livelihood and regarding these, all or a majority of the society must acknowledge a set of rules and regulations, and sanction their validity. Thus, no society may continue its existence without a series of norms, rules, traditions, and regulations.

Accordingly, having only a series of norms and regulations can never be enough for the continuance of a society because as it has been shown no two humans are similar in their existential constitution—hence, in their intellect, volition, and methods. Therefore, even though human individuals may be united in their general thoughts, they are unquestionably at variance in details and would surely not make the same choices.

As a result of this certain dissimilitude, at the first step each person tends to rush in a different direction bringing about the collapse of common laws and norms.

In addition, as far as the history of human life shows and observation of various human societies with varying methods of government confirms, survival of every society requires an individual or an office whose intellect and volition governs and controls the intellects and volitions of the citizenry and guards and supports the governmental system that has been implemented in the society. These conditions are manifest in all societies without exception.

Humankind, with its God-given make-up [fitrah], is not ignorant of them and does not remain inactive. Willing or unwilling, the people of each society elect an individual or office to oversee them and administrate their affairs. They ask their chosen—just as a guardian that is the custodian of an orphan, the head of the family, and responsible for managing the affairs of the young family members—to rule over the people as a king or president.

We name this office, according to which an individual or office becomes in charge of the affairs of others and manages their lives, like a real individual, trusteeship [wilāyat]. It has almost the same meaning that we understand from the words leadership and guardianship.