The Necessity of Imamate and the Qualifications of an Imam

From the Shi'ah point of view, the institution of Imamate is necessary, according to reason. It is lutf (grace) of Allah which brings the creature towards obedience and keeps him away from disobedience, without compelling the creature in any way.

Imamate is a lutf, because as we know when men have a chief (ra'is) and guide (murshid) whom they obey, who avenges the oppressed of their oppressor and restrains the oppressor, then they draw nearer to righteousness and depart from corruption.

And because it is a lutf, it is incumbent on Allah to appoint an Imam to guide and lead the ummah after the Prophet.
[al-'Allamah al-Hilli: al-Babu 'l-hadi 'ashar, Eng. tr W.M. Miller, pp. 50, 62-4.]

Superiority

The Shi'ahs believe that, like the Prophet, an Imam should excel the ummah in all virtues, such as knowledge, bravery, piety and charity, and should possess complete knowledge of the Divine Law. If he does not, and this high post is entrusted to a less perfect person when a more perfect one is available, the inferior will have been given preference over the superior, which is wrong in reason and against Divine Justice. Therefore, no inferior person may receive Imamate from Allah when there exists a person superior to him.
[Ibid. p.69]

Infallibility

The second qualification is 'ismah (infallibility). If the Imam is not infallible (ma'sum) he would be liable to err and also deceive others.
[Ibid. p.69]

1. Firstly, in such a case, no implicit confidence may be placed in what he says and dictates to us.
2. Secondly, an Imam is the ruler and head of the ummah and the ummah should follow him unreservedly in every matter. Now, if he commits a sin the people would be bound to follow him in that sin as well. The untenability of such a position is self-evident; for obedience in sin is evil, unlawful and forbidden. Moreover, it would mean that he should be obeyed and disobeyed at one and the same time; that is, obedience to him would be obligatory yet forbidden, which is manifestly absurd.
3. Thirdly, if it would be possible for an Imam to commit sin it would be the duty of other people to prevent him from doing so (because it is obligatory on every Muslim to forbid other people from unlawful acts). In such a case, the Imam will be held in contempt; his prestige will come to-an end and instead of being the leader of the ummah he will become their follower, and his Imamate will be of no use.
4. Fourthly, the Imam is the defender of the Divine Law and this work cannot be entrusted to fallible hands nor can any such person maintain it properly. For this very reason, infallibility has been admitted to be an indispensable condition to prophethood; and the considerations which make it essential in the case of a prophet make it so in the case of an Imam and caliph as well.

Appointment by Allah

But, as in the case of the prophets, the above-mentioned qualifications alone are not enough to automatically make one an Imam. Imamate is not an acquired job; it is a 'designation' bestowed by Allah.

It is for this reason that the Shi'ah Ithna 'Asharis (The Twelvers) believe that only Allah can appoint a successor to the Prophet; that the ummah has no choice in this matter-its only duty is to follow such a divinely-appointed Imam or caliph.

The Sunnis, on the other hand, believe that it is the duty of the ummah to appoint a caliph.

Verses of the Holy Quran

The following verses of the Qur'an confirm the views held by the Shi'ahs:

And thy Lord creates what He wills and chooses; they have no right to choose; glory be to Allah, and exalted be He above what they associate! (Holy Quran 28:68).

This clearly shows that man has no right to make any selection; it lies entirely in the hands of Allah.

Before creating Adam (as), Allah informed the angels:

... "Verily I am going to make a caliph in the earth ". . . ( Holy Quran 2: 30).

And when the angels demurred politely at the scheme, their protest was brushed aside by a curt reply: "Surely I know what you know not" (ibid.). If the ma'sum (infallible) angels were given no say in the appointment of a caliph, how can fallible humans expect to take the whole authority of such an appointment in their own hands?

Allah Himself appointed Prophet Dawud (as) as caliph on the earth-

"O Dawud ! Verily; We have made thee (Our) caliph on the earth ..." (Holy Quran 38:26)

In every case Allah attributes the appointment of the caliph or the Imam exclusively to Himself.

Likewise, the call went to Prophet Ibrahim (as):

(Allah) said: "Surely I am going to make you an Imam for men." (Ibrahim) said: "And of my offspring?" He said: "My covenant will not include the unjust. " (Holy Quran 2 : 124)

This verse leads us to the correct answers of many important questions concerning Imamate.

a. Allah said: "Surely I am going to make you an Imam for men. " This shows that Imamate is a divinely-appointed status; it is beyond the jurisdiction of the ummah.

b. "My covenant will not include the unjust." This clearly says that a non-ma'sum cannot be an Imam.