Then the chain of mujtahid faqihs started since then...

Then the chain of mujtahid faqihs started since then, and it has continued till our present time uninterruptedly. During each period, one or more marji` rises to distinction among the nation whom the Shi`as follow in their actions. This is done in accordance with the scholarly books of instruction ( risalas ) which each marji` derives from the Book of Allah and the Sunnah without expressing any personal views except in reference to issues related to modern times.

Such views are relevant to modern scientific and technological progress such as heart or organ transplantation operations, artificial insemination, banking transactions, etc. One particular mujtahid may be distinguished with prominence over all the rest through the degree of his knowledge. Shi`as refer to such a mujtahid as al-marji` al-a`la , the supreme religious authority, or the head of the sect or of al-hawza al-`ilmiyya , the university-type circle of top scholars.

This wins him the regard and respect of all other authorities. Across the centuries, Shi`as follow their contemporary faqih who undergoes whateverever problems other people undergo and is concerned about whatever concerns them, so they ask him and he provides them with the answers. Thus have the Shi`as in all ages maintained the two basic sources of Islamic Shari`a : the Book of Allah and the Sunnah, in addition to the texts transmitted by the Twelve Imams from the pure Progeny of the Prophet.

Hence, their scholars feel no need at all to resort to analogy, or to express a personal viewpoint, because Shi`as have taken pains to record and safeguard the Prophet's Sunnah since the time of Ali ibn Abu Talib and will continue to do so till the Day of Judgment. The Imams from his offspring have been inheriting the same: son from father, and so on, treasuring such texts as people treasure their gold and silver.

We have already quoted the statement of the Martyr Ayatullah Muhammad Baqir al-Sadr which he records in his own risala indicating that he does not rely except on the Holy Qur'an and Sunnah. Mentioning Martyr al-Sadr is only an example; all Shi`a authorities without any exception do the same.