Now we have reached the fourth question which is: Supposing that the hypothesis of the Expected Leader and all that it comprehends of prolonged life, early leadership and a silent absence, is possible, that would not be enough proof for his existence, thus, how can we indeed believe in the existence of al-Mahdi?
Would some narratives related in books on the Great Messenger (peace and blessing of Allah be upon him and his progeny) be enough for perfect conviction in the existence of the Twelfth Imam, in spite of what this supposition bears of peculiarity and deviation from the norms? Or rather, how can we prove that al-Mahdi had a true historical existence and that he is not only an assumption, for which psychological circumstances have been combined to confirm his existence in many people's minds?
The answer is: That the idea of al- Mahdi, as the Expected Leader, who will change the world for the best, has been already mentioned in several of the narratives (ahadith) related from the Great Messenger in general, and the Imams of Ahlul Bayt in particular. Moreover, it has been reconfirmed, with a degree beyond doubt, in many texts.
I could count up to four hundred narratives of the Prophet (peace be upon him and his progeny) which reached us through our brothers, the Sunnis, (e.g., the book al-Mahdi written by my uncle as-Sayyid Sadru'd-Din as-Sadr, may Allah bless his noble soul), as well as a great number of reports about al- Imam al- Mahdi through both the Shi'ites and the Sunnis - nearly more than six thousand narratives, (e.g., the book entitled Muntakhab al-athar fi al-Imam aththani 'ashar [Selection of traditions concerning the Twelfth Imam] by ash-Shaykh Lutfu'llah as-Safi), which is very high statistical number, not found in many of the self-evident Islamic issues.
As regards the materialization of this idea in the Twelfth Imam (peace be upon him) we do possess enough justifications to be convinced that he is the one They can be summed up into two groups of evidence - the first Islamic, and the other scientific.
By the Islamic evidence we confirm the existence of the Expected Leader.
By the scientific evidence, we can prove that al-Mahdi is not just a myth or a supposition but a reality which has been confirmed by historical experience The Islamic evidence appears in the hundreds of narratives related from Allah's Messenger (peace and blessing of Allah be upon him and his progeny) and the Imams of Ahlul Bayt (peace be upon them), which prove that al- Mahdi will be appointed as Imam, that he is from the descendants of the Prophet and Fatimah and the ninth descendants from al-Husayn, that the caliphs (Prophet's successors) are twelve.
All of these narratives limited that universal idea by personifying it in al-Mahdi, the Twelfth Imam of Ahlul Bayt. Moreover they reached a great number and diffusion, although the Imams took a great precaution and care, fearing their exposure on a general level, in order to protect the righteous descendants against assassination or an unpredicted assault on his life.
However, the numerical abundance of these narratives is not the only reason for their validity, for in addition to this, there are certain virtues and coherences to be taken into account for proving their validity.
The Prophet's narratives (ahadith) about the fact that the Imams, caliphs, or amirs - depending on the style of the narrative in its different ways are twelve Some writers counted up to more than two hundred and seventy narratives taken from the most well-known books of Sunni and Shi'ah traditions such as al-Bukhari, al-Muslim, at-Tirmidhi, Abu Dawud and the collection of Ahmad ibn Hanbal and the Rectification of the Judge on the Two Sahihs (al- Hakim, Mustadrak 'ala s-sahihayn).
We should bear in mind here that al-Bukhari who had compiled these narratives, was a contemporary to both al-Imam al-Hadi and al-Imam al-'Askari which means quite a lot, since it proves that the narratives were recorded from the Prophet (peace and blessing of Allah be upon him and his progeny) before that the realization of their contents and the idea of the Twelfth Imam had materialized.
This means, therefore, that there is no room left for doubt, that the recording of the narratives was not influenced by the fact of the Twelfth Imam, or that it might have been a reflection of it, because the false narratives (ahadith) that are related from the Prophet ( peace and blessing of Allah be upon him and his progeny) are either a reflection or a justification for a fact occurring later in time.
Now, they did not precede in their appearance and recording in the books, that fact which they came to reflect, therefore, as long as we possess the material evidence, which is that the mentioned narrative had already preceded the historical sequence of the twelve Imams, and that it had been recorded in the books of ahadith (books of traditions) before that the event took place, we can be sure that this narrative is not a reflection of an event but an expression to a truth from Allah, uttered by the one who did not speak out of fancy (the Holy Prophet) when he said: "Surely the caliphs after me are twelve".
So, the event of the twelve Imams was fulfilled, starting with al-Imam 'Ali and ending in al-Mahdi, this way being the only rational interpretation to that noble narrative of the Prophet.
As far as the scientific evidence is concerned, it is formed out an experience, lived by a community of people, lasting nearly seventy years, which we call the period of the minor occultation (ghaybah as-sughra) To elucidate this point, we will pave the way by giving a brief description
This minor occultation marks the first phase in the Imamate of the Expected Leader (peace be upon him) From the time that had been predestined, from the time he assumed the role, he remained hidden from the outside world, distant from all the events that were taking place although being at the same time proximate to them in his mind and heart
We should bear in mind that had this occultation occurred suddenly, the result would have been a great shock among the popular masses, who believed in the Imamate since they were used to contacting their Imam in every period, to consulting him for solutions to their various problems.
Thus, had he suddenly vanished, his supporters would have felt cut off from spiritual and intellectual leadership Such an event would have created an enormous gap which would have thoroughly shaken the whole structure and undermined its unity. Therefore, it proved necessary that the way should be paved to this occultation, so that these bases might get used to it and gradually adapt themselves to the new situation
So the plan was this minor occultation, during which al- Imam al-Mahdi vanished from the universal scene, while keeping in touch with his popular bases and supporters through his delegates or representatives and the most reliable among his companions, who acted as a link between the Imam and those who believed in his line.
The position of representative of the Imam was held in those times, by four personalities, whom the popular bases agreed as to their fear of Allah, piety and integrity. They were:
1) 'Uthman ibn Sa'id al-'Amri;
2) Muhammad ibn 'Uthman ibn Sa'id al-'Amri;
3) Abu'l-Qasim al-Husayn ibn Ruh; and
4) Abu'l-Hasan 'Ali ibn Muhammad as-Samuri.
These four individuals assumed the role of representative of the Imam (al-Mahdi) according to the above classification. So whenever one of them died, the other succeeded him, after being designated by al- Imam al-Mahdi (peace be upon him).
The representative of the Imam used to get in touch with the Shi'ahs and submit their questions and problems to the Imam and return to them with his answers. Sometimes orally and very often in a written form. So these masses who lacked the vision of their Imam, found some comfort and consolation in these indirect communications.
Moreover they could notice that the signatures and the letters were all written in the same way, during the time of the four representatives that lasted nearly seventy years The last representative, as-Samuri, declared that the period of the minor occultation, which was characterized by the designated delegates, was over; that the period of the major occultation, in which there would be no designated individuals to mediate between the Imam and the Shi'ites, had began.
This transition meant that the minor occultation had already accomplished its mission and achieved its goal, since it immunized the Shi'ites against the great shock and the feeling of the profound gap caused by the Imam's occultation. In that way, it enabled them to adapt themselves to the situation and gradually prepared them to accept the idea of general representation on behalf of the Imam. By this token the latter changed from a representation by a designated individual to a more general line manifested in the just mujtahid (a legalist who arrives at an independent judgement), who has a keen insight into the religious and worldly issues of the Muslims, in view of the transition from the minor to the major occultation
Now you can have an idea about the situation, in the light of what has been discussed up to now, so you can clearly realize that al- Mahdi is a reality that a community of people has lived and which has been expressed for seventy years, by the representatives and the mediators of the Imam, whom no one could suspect of cheating nor of playing on words
For can you imagine - by your Lord - that a lie could survive for nearly seventy years, which four individuals would successively assume and agree upon and continue to interact with others on its basis as if it were a reality that they lived; that nothing would escape their control, which would cause a doubt in people's minds; that there would be no particular relation between the four through which they could gain the trust of everyone and their belief in the truth of the matter, which they pretend to live and feel?
An old proverb said, "The rope of lies is short". also logic in life confirms the fact that it is impossible that a lie could survive in this way and for all time through these relations and still wins everyone's confidence.
Thus, the phenomenon of the minor occultation can be considered as a scientific experiment which has confirmed the factual objectivity of the Imam's existence, his birth, life and occultation, on account of which he has been hidden from the world and has not revealed himself to anyone ever since.