[The Imamate According to the Zaydīs]

Answer, and with Allah is success: If the question and objection is coming from the Imāmiyyah, then the answer to them is:
The evidences that the ummah has narrated and agreed upon the soundness of, such as the ḥadīth of the Two Weighty Things (ḥadīth ath-thaqalayn), indicate that the People of the House (Ahl al-Bayt) are the successors of the Prophet (May Allah bless him and his family and grant them peace) and those who stand in his place, and so on. The Imāmiyyah claimed explicit textual designation (naṣṣ) of the Imamate for twelve imams, named individually, whose last is Muḥammad ibn al-Ḥasan al-ʿAskarī (Peace be upon him), who — according to their claim — was born and went into concealment in the middle of the third century. Then they did not bring, for their claim, any conclusive proof; rather, they rely upon narrations which they alone relate, without others.
So we rejected their claim and we, the Zaydīs, held fast instead to the evidences whose soundness the entire ummah has agreed upon, and we paid no heed to the statement of the Imāmiyyah, because of its lack of proof and evidence.
- At that point, nothing remains but that we profess the Imamate of the People of the House (Ahl al-Bayt) until the Day of Resurrection. What is meant by “the Imamate of the People of the House” is the Imamate of their scholars. Whoever their scholars appoint as imām, bear witness to his Imamate, and declare obedience to him, then he is the imām whose obedience Allah has made obligatory.
- It was obligatory upon the believers to gather under his banner and to worship Allah by professing loyalty to him and his Imamate. To this conclusion the evidences that the various sects have agreed upon in their soundness have led us, and we saw no alternative but to submit to them and stop at them.
- It is not hidden that the Zaydīs do not profess the Imamate of an imām from the People of the House (Peace be upon them) unless he fills the place which the Prophet (May Allah bless him and his family and grant them peace) used to fill, in the domain of authority, of abundant knowledge, humility, justice, fairness, asceticism, scrupulousness, perfection of intellect, soundness of opinion, good governance, gentleness, discernment, generosity, and courage. If the imām is such, and the scholars of the People of the House bear witness to that about him and appoint him as imām, then he is (indeed) the imām.
- Indeed, if the imām gathers in himself the qualities we have mentioned and calls the people to give him allegiance, then he is the imām, and it is not a condition that the scholars of the People of the House appoint him.
- Our saying earlier that the People of the House bear witness to his Imamate and appoint him as imām is only for the sake of enabling people to come to know his Imamate. The generality of Muslims only infer the Imamate of an imām from the testimony of the scholars, their legal opinions, and the like.
- If some of the scholars give allegiance (bayʿah) to a man for the Imamate, and other scholars give allegiance to another man for the Imamate, and then each of them insists on his own Imamate and disputes and hostilities arise between them, etc.; then it is obligatory upon the believer to withhold judgment until the true Imam becomes clear to him.
- If the Imam does not become clear to him, then he must withhold judgment, and it is not permissible for him to invalidate the Imamate of either of them without proof.
- And the fighting of the two Imams is not evidence for the invalidity of both of their Imamate, and that is because:
it is assumed that each one of them possesses the qualities of Imamate in the most complete manner, since the scholars of the Zaydiyyah do not appoint to the Imamate except one who is such. And if each one of them is so, then the true Imam among them is the one whose pledge of allegiance preceded the pledge of the other, while the other Imam is mistaken in disputing his companion.
- Moreover, dispute and fighting between the two Imams only occurs when each of them believes that he is more complete than the other, more encompassing of the qualities of Imamate, sounder in opinion, more perfect in intellect, more abundant in knowledge, and more insightful in managing the affairs of authority, etc.
In any case, the one whose pledge preceded is the Imam, and the other is mistaken yet excused, because he sees himself as the most complete and the most encompassing of the qualities of Imamate.
- In all cases, the reality is that the call of the two Imams is one, their school is one, and the principles of their beliefs and their branches are one. They do not differ in their doctrines, nor do they call to anything other than what those before them from the Imams called to.
- The disagreement between the two Imams is only regarding which of them is more entitled to stand at the head of that call, and that does not harm the Imamate of either of them; the one who opposes is mistaken yet excused.
- This is with the rarity of fighting between the Imams of the Zaydiyyah. What occurred of that was between al-Ḥusayn ibn al-Qāsim al-ʿAyyānī and al-Zaydī. As for others besides them from the Imams of the Zaydiyyah, fighting did not occur between them, even if disagreement occurred over who deserved the Imamate.
As for Imam Aḥmad ibn al-Ḥusayn, the (Ṣāḥib Dhībīn), the fighting was between him and one who was not an Imam.
As for what is mentioned in the history of the Imams of the Zaydiyyah regarding fighting, it is between two who are not Imams, or between an Imam and one who is not an Imam. And if we were to examine carefully and investigate thoroughly what occurred between al-Zaydī and al-Ḥusayn ibn al-Qāsim, we would know that one of them was an Imam and the other was not an Imam.
From here, we can say that no fighting ever occurred between two Imams from among the Imams of the Zaydiyyah at all.

Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.3