In his papers entitled the Notes on Leadership and Administration the author has described very well the difference between Prophethood and Imamat. The first is guidance and the second is leadership. As a religious guide or Prophet is a sort of Divinely appointed guide, the same case is with a leader or an Imam. The Holy Prophet and some other Prophets have been both the guides and the leaders. But the end of Divine guidance does not mean the end of Divine leadership also.
The same notes say that Imamat and Prophethood are two different assignments and two different states. They are often separable. Many Prophets only conveyed revelations. They were not the Imams. Similarly the Imams of the Prophet's House have not been the Prophets. Anyhow, Ibrahim and Muhammad were the Prophets and the Imams both (Peace be upon them). The Qur'an says: "I am going to Make you Imam for the people." (Surah al Baqarah 2:124 )
Our contention that Prophethood is guidance and Imamat is leadership has been derived from the Quran, which says: "The Messenger has only to convey the message of Allah." (Surah al Maidah 5:99)
But we know that the duty of an Imam is to supervise, to lead and to take care of those who accept his leadership.
According to the Shi'ah belief, as Prophethood is conferred by Allah, Imamat is also granted by Him. In this respect there is no difference between Prophethood and Imamat. The distinguished Prophets have been guides as well as leaders. The end of Prophethood means the end of Divine guidance in the sense of showing the way and delivering the message, but Divine leadership or Imamat shall never come to an end.
Difference Between Guidance and Leadership
According to one definition the leader is he who makes it easy for his followers to achieve the required goal. The guide on the other hand not only shows the way, but also often provides the means of traversing it and reaching the goal.
As a matter of fact a person may hold simultaneously both the assignments of a guide and a leader, or may hold only one of them. As we have already said, Prophethood is a sort of guidance and Imamat is a sort of leadership. It is possible that one person may be both a guide and a leader. It is also possible that someone may be only a guide and not a leader like all our genuine preachers. (Those whose preaching is not proper are out of question.) They themselves stand aside and show the pitfalls to others. Their responsibility ends there. In contrast, it is also possible that someone may be a leader, not a guide. That happens when the way is known and the goal has already been determined. In this case a leader is required to awaken the dormant forces, to mobilize them and to push them forward. Similarly it is also possible that one person may be a leader and a guide both.
Imamat of the Holy Imams and the Tradition of Thaqalayn
The tradition (Hadith) of Thaqalayn is an authentic tradition reported by numerous authorities both the Shi'ah and the Sunnis. According to it the Holy Prophet is reported to have said: "I leave among you two heavy trusts: the Book of Allah and my chosen descendants." 
This tradition has been usually used as a prelude to the narration of the misfortunes of the Holy Prophet's Chosen descendants. The preachers say: "This was the Holy Prophet's direction, but no sooner than he died. . . ." This description gives the impression that the members of the Holy Prophet's House were crushed and made totally ineffective. Though it is true that their services were not utilized as they should have been, yet it must be admitted that their presence was extraordinarily effective in the preservation of Islamic heritage. Of course the then government as well as Islamic politics deviated from their original course and the members of the Prophet's House could render no service in that field, but they so protected and kept alive the spiritual heritage of Islam and the Holy Prophet, that it remained safe even after the gradual decline and extinction of the Islamic caliphate.
Islam is a code of life which covers all affairs temporal and spiritual. It is not like the school of a moral teacher or a philosopher which can deliver to society nothing more than a few books and a few pupils. Islam besides being a moral and cultural school and a social and political system, is a new code of life and a new way of thinking. It practically brings new arrangements into existence. Islam preserves the spirit in the matter, the invisible in the visible, the life Hereafter in this world and finally the kernel in the husk and the husk in the kernel.
The deviation of the government from its original course rendered the institution of caliphate into mere husk. Outward formalities were kept intact, but the spirit of piety, truthfulness, justice, sincerity, love, equality and patronage of science and knowledge did not exist, especially during the Umayyad period when true knowledge was despised and discouraged. The only thing which was encouraged was poetry, pre-Islamic customs and boasting of one's ancestry. The result was that politics was separated from religiousness. In other words those who represented spiritual heritage of Islam were not allowed to take part in political affairs and those who held political power were alien to the spirit of Islam, and carried out only its outward formalities such as congregational prayers and the appointment of the officials to perform Islamic duties. They were caliphs and the commanders of the faithful only in name. At last even this duality disappeared and the outward formalities were also gone. Even the form of government officially became pre-Islamic. Spirituality and religiousness were totally separated from politics. From here it can be understood that the biggest blow which was dealt to Islam began from the day that religion and politics were separated from each other. Though during the days of Abu Bakr and Umar religion and politics still to a certain extent went together, the seeds of their separation were sown during that period. The things so developed that Umar made repeated mistakes and Imam Ali corrected them. Fortunately Imam Ali was his regular adviser. The separation of religion and politics being the greatest threat, the well-wishers of Islam wanted to keep them together. The relation between these two is that of spirit and body. The body and spirit and the husk and kernel should remain united. The husk is required to protect the kernel from which it draws its strength. Islam gives importance to politics, government, political laws and jihad only for the purpose of protecting and preserving its spiritual heritage, that is monotheism, supremacy of spiritual and moral values, social justice, equality and regard for human sentiments. If this husk is separated from its kernel, the latter will be damaged and the former will become of no use.
The bold action which the Imams took was the protection of the spiritual heritage of Islam. They separated from Islam the institution of caliphate as it existed. The first Imam who took this action was Imam Husayn (AS). His uprising made it clear that Islam meant piety, recognition of Allah and self-sacrifice for His cause, not the values introduced by the Umayyad Caliphate.
Now let us see what the spiritual heritage of Islam means and how the Holy Imams have protected it. The Holy Quran says: "The Prophet reads out to them Allah's verses, purifies them and teaches them the Book and wisdom" (Surah Jumu'ah 62:2 )
It also says: "So that the people may establish justice." (Surah al Hadid 57:25 )
Again it says: "We have sent you as a witness, a bringer of good tidings, a warner and one who calls to Allah with His permission." (Surah al-Ahzab 33: 45)
The Imams first of all urged people to do what is good and abstain from that which is evil. The most extreme example of this sort of action is Imam Husayn's uprising. Secondly the Imams paid attention to disseminating knowledge. An example of this action is Imam Ja'far Sadiq's school, which produced such eminent scholars as Hisham, Zurarah and Jabir ibn Hayyan.
The same purpose was served by the Nahjul Balaghah, the Sahifah Sajjadiyah and the disputations of all Imams, especially those of Imam Riza. Above all the Imams showed practical piety, asceticism, selflessness and benevolence. They passed their nights in worshipping Allah and helped the poor and the weak. They possessed the noble Islamic qualities of forgiveness, beneficence and humility. Their very sight reminded the people of the moral and spiritual qualities preached by Islam and the Holy Prophet. Imam Musa Kazim observed vigils in close vicinity to Harun's palace. Imam Riza, when he was still the heir apparent, declared: "Allah of all the people is the same, their father is the same and their mother is the same. None is superior to others except by virtue of piety." He took meals with the barber and the door-keeper and mixed freely with them.
The spiritual philosophy of Islam is the preservation of its moral and spiritual heritage and the retention of its kernel in contradistinction of its husk. The separation of spirituality from politics amounts to the separation of the kernel from its husk.
Imamat and Hadith of Thaqalayn
(i) The substance of this tradition is mutawatir, which means that it has been reported by numerous irreproachable authorities. Its wording may vary, but according to most of the reports it is as under: "I am leaving among you two heavy trusts: The Book of Allah and my chosen descendants. So long as you adhere to them, you will never go astray. They will not be separated from each other till they come to me at the fountain."
Once in an article published in an issue of the magazine, Risalatul Islam, the organ of the Dar ut-Taqrib Baynal Mazahibul Islamiya this tradition appeared thus: "I am leaving among you two heavy trusts: the Book of Allah and my Sunnah." Immediately, at the instance of the late Ayatullah Burujardi, a scholar of Qum, named Shaykh Qiwamuddin Wishnawahi wrote a treatise entitled Hadithuth Thaqalayn and sent it to the Darut-Taqrib which published it as a separate treatise.
In that treatise the sources of this tradition have been traced in the books of traditions, the commentaries of the Quran, biographies, historical books and dictionaries, in which this tradition has been mentioned for different reasons. For example it is mentioned in the commentaries of the Quran in connection with the verse: "We will dispose of you O you Thaqalayan." and in connection with the verses of 'I'tisam' (3:103), 'Mawaddat' (42:23) and 'Tathir' (33:33). In dictionaries it is mentioned in connection with the root-word, thaqal etc.
(ii) In the Holy Quran the word, thaqalayn has been used to signify the men and the jinn. Let us see what it signifies in this tradition.
In connection with the tradition there are a few points worth mentioning. The first point is: Why have the Chosen descendants of the Holy Prophet been called thaqal?
The second point is: Why has the Quran been called the major thaqal and the chosen descendants of the Holy Prophet the minor thaqal? Some reports have these words: "One of them (the thaqals) is greater than the other."
The Holy Prophet was asked as to what he meant by the thaqalayn. He said: "The Book of Allah, the one end of which is in Allah's hand and the other end of which is in your hand, and my descendants who are the minor thaqal".
According to a certain report, he added: "They are the two ropes which will not break off till the Day of Resurrection."
(iii) The third important point in this connection is that the Holy Prophet has said that these two will not be separated. He did not mean to say that they will not part company with each other or that they will not be displeased with each other or that they will not quarrel. What is meant is that adherence to one of them is inseparable from adherence to the other. They cannot be separated by saying that the Quran is enough for us as Umar said in the early days of Islam or by saying that what has been reported to us from the Prophet's House is enough for us as the Akhbarists say. Incidentally some of the Shi'ah scholars are of this opinion.
(iv) The fourth point is that the Holy Prophet has guaranteed that those who really adhere to these two thaqa1s would never go astray and would not feel miserable.
The decline and deviation of the Muslims began when they tried to thrust a wedge between these two thaqals.
Now let us discuss why the law-giver has chosen to append something else to the revealed Book brought by him.
This question is related to the profundity and subtlety of the Quran, the law of which requires an interpreter and commentator. To illustrate this point it may be said that sometimes we import from a foreign country such simple goods as cloth, shoes or utensils. In this case we do not need any persons to come along with the goods to direct us how to use them. We can sew garments out of cloth, can use the utensils and put on the shoes. But sometimes we import a complete manufacturing plant. In that case it is necessary that some experts should come along with it to install it and operate it for a fairly long time till our own technicians are ready to operate it independently. Similarly when modern war equipment is imported, it should definitely be accompanied by technicians to teach its use.
We have heard that recently France has sold mirage aircraft to Libya, but it is said that the Libyan pilots will not be in a position to fly them at least for two years.
Hence the question of leadership in the sense of religious authority, to which the Holy Prophet has referred in this authentic tradition, is nothing but a stress on the fact that it is not enough to know Arabic in the ordinary sense to be able to interpret the Qur'an, to understand its aims and to explain its injunctions and moral rules. We know how the literal interpretation of the tradition which says that you will see your Lord on the Day of Resurrection as you see the moon when it is full, led to gross deviation and anthropomorphic conceptions.
To say that the Book of Allah is enough for us culminates in either Ash'arism or Mu'tazilaism, each of which was a heretical school of thought.
Our twelve Imams are the Qur'anic technicians. Their knowledge does not belong to the world of senses. It is Divinely inspired or at least especially acquired knowledge. Imam Ali once addressing Kumayl said: "Knowledge with real insight came to them unexpectedly. They experienced the satisfaction of conviction. They found easy what those living in luxury considered to be difficult, and they were on intimate terms with that, of which the ignorant were afraid." (See Nahjul Balagha, Saying 146)
Imam Ali says: "The chosen descendants of the Holy Prophet keep his trust and abide by his orders. They are a treasure of his knowledge, a sanctuary of his wisdom, an archive of his Books and a support of his religion. With their help he straightened his back and gained his composure. None from among his ummah (followers) can be compared to them. Those who received their favours cannot be equal to them. They are the basis of religion and the pivot of faith. To them return those who go astray and those who lag behind, join them for guidance and salvation. They are efficiently capable and fit for the status of leadership; they have been and are even now rightful heirs of the Holy Prophet who had entrusted them Imamate." (Nahjul Balagha - Sermon 2)
"Through us you were guided in the darkness and were able to set your foot on the highway. With our help you came into the light of the dawn from the darkness of the late night. Deaf be the ear that does not listen to the cry (advice) of the guide." (Nahjul Balagha - Sermon 4) (This sermon was delivered by Imam Ali after Talhah and Zubayr were killed).
"You will not be observing the covenant of the Qur'an unless you know who violated it and you will not be adhering to it unless you know who threw it away. Therefore seek this information of those who have it, for they are the life of knowledge and the death of ignorance. It is they whose judgement will tell you of their knowledge, whose silence will tell you of their speech and whose outward appearance will tell you of their inward feelings. They do not do anything that is against religion nor is their opinion divided about it. Therefore religion is their true witness and a silent speaker." (Nahjul Balagha -Sermon 147)
(The words "that they do not do anything against religion", indicate the infallibility of the Imams and the words, "their opinion is not divided" show that the Imams possess profound knowledge.)
"They are life of knowledge and death of ignorance. Their gentleness speaks of their knowledge and their silence of the wisdom of their speech. They neither oppose the truth (as they are infallible) nor have they divided opinion about it, (as their knowledge is sound and correct). They are pillars of Islam and the place where it is safe. Through them the truth was restored to its position, the falsehood was displaced and its tongue was cut off. They understand religion and take care of it. They do not merely hear it and pass it on. The transmitters of knowledge are many, but its adherents are very few." (See Nahjul Balagha - Sermon 239).
"A time will come after me when nothing will be more hidden than truth and more manifest than falsehood. At that time the Quran and the people of the Quran will be the rejected outcasts. The Qur'an and its guardians (Ahlul Bayt) which are like two companions going together in the same path, will not be accommodated by anyone. At that time they will be among the people, but no one will seek guidance from them, and they will be with the people, but not really with them." (Nahjul Balagha - Sermon 147)
 In this connection a reference may be made to Shaykh Qawam Wishnawahi's treatise appended to Risalatul Islam and to the Biharul Anwar, an account of the Prophet's life.
 Shaykh Qiwamuddin says that this tradition has been reproduced in Sahih Muslim, Vol. VII, p. 122, Sunan Tirmizi, Vol. II, p. 307, Sunan Abu Da'ud, Vol. V, pp. 182, 189; Mustadrak Hakim, Vol. III, pp. 14, 17, 26, 59, Vol. VI, pp. 366, 371, Vol. V, pp. 182, 189; Mustadrak Hakim, Vol. III, p. 109, Tabaqat of Ibn Sa'd, Vol. IV, p. 8; Usudul Ghabah, Vol. II, p.12, Vol. III, p. 147 and Ibn Abil Hadid.