The History of Ilm-ul Usul
Ayatullah Muhammad Baqir al-Sadr
'Ilmul Usul developed in the lap of 'Ilmul Fiqh just as the latter developed in the lap of 'Ilmul Hadith (the science of traditions) as a result of the various stages through which 'Ilmush Shari'ah passed.
By 'Ilmush Shari'ah we mean the science that endeavors to come to know the laws which Islam has brought from Allah the Most High. The beginning of this science in Islam is represented by the campaign of a large number of narrators to preserve and collect the traditions (al-Ahādith) that appear in the laws of the Shari'ah. Thus in the first stage 'Ilmush Shari'ah was at the level of 'Ilmul Hadith. At that time the basic task seems to have been confined to collecting the traditions and preserving their texts. However as for the method of understanding the laws embodied in those texts and traditions, it was not so important at that stage, because it then consisted of nothing more than the simple method by which people understood the words of each other in their everyday conversation. Gradually the method of understanding the laws of the Shari'ah from the texts became more and more complex, until the derivation of laws from their legal sources became abstruse demanding profound and comprehensive knowledge. Increasing and exhaustive efforts were made to acquire that profundity which the understanding of the laws of the Shari'ah from the texts and their derivation from their sources demanded. Thus the seedlings of academic legal thought developed and 'Ilmul Fiqh was born. Then 'Ilmul Shari'ah ascended from the level of 'Ilmul Hadith (science of traditions) to that of deduction and of Istidlāl (setting out proofs and reasoned arguments) which is abstruse.
During that growth and development of 'Ilmul fiqh and of legal thinking and the embarkation of the scholars of the Shari'ah upon carrying out the process of deduction and understanding the laws of the Shari'ah with the degree of profundity and depth demanded by the situation, the common threads (the common elements) of the process of deduction began to appear and to reveal themselves. This was how the birth of 'Ilmul Usul took place and how the legal thinking of the outlook of 'Ilmul Usul was adopted.
Hence we can say that the science of the principles of jurisprudence was born in the lap of 'Ilmul Fiqh. Thus, while previously' those carrying out the tasks of Fiqh were using the common elements in the process of deduction without completely grasping their nature and limitation and the significance of their role in it -the entrance of the trend of 'Ilmul Usul onto the stage of the thinking of 'Ilmul Fiqh, they began to pay attention to these common elements and to study their limitations.
We do not doubt that the seeds of the thinking of 'Ilmul Usul were to be found with the jurists among the companions of the Imams since the days of the Sadiqain (Imam Muhammad Baqir and Imam Ja'far Sadiq) at the level of their legal thinking. Historical testimony to that is contained (among other things) in the books of Ahādith (traditions) about the questions concerning some of the common elements in the process of deduction posed by a number of narrators to Imam Sadiq and other Imams and the answers received from them. Those questions reveal the existence of the seeds of the thinking of 'Ilmul Usul among them and their tendency to establish general laws and to delineate the common elements. This view is strengthened by the fact that some pf the companions of the Imams like Hisham bin Hakam wrote booklets on some of the problems of 'Ilmul Usul. Hisham wrote a book on 'Terms'.
However, in spite of that, the concept of common elements and the significance of their role in the process of deduction were not sufficient clear and propound in the beginning. The elucidation of these characteristics and their increase in comprehensiveness took place gradually during the expansion of the tasks of 'Ilmul Fiqh and the development of the processes of deduction. But the study of these common elements did not become a separate study, independent of the researches of 'Ilmul Fiqh, until a long time had elapsed after the birth of the first seeds of the thinking of 'Ilmul Usul. Thus the study of 'Ilmul Usul remained for a long time mixed with the researches of 'Ilmul Fiqh and not independent of it. The thinking of 'Ilmul Usul in the meanwhile intensified its role with, increasing clarity until it reached the degree which enabled it to become independent of 'Ilmul Fiqh.
It seems that up to the time 'Ilmul Usul reached the level which qualified it for independence, it continued to waver between 'Ilmul Fiqh and 'Ilmul Usulud Din (science of theology). Thus sometimes these researches were mixed with the researches of Usulud Din and Kalām (scholastic theology) as Sayyid Murtaza has indicated in his book on 'Ilmul Usul called al-Zari'ah in which he says, "I have tome across one who has devoted a book to Usulul Fiqh and its Styles and overstepped and exceeded its bounds extensively, and even though he was right in the detailed presentation of its meaning, principles and forms, yet he strayed away from Usulul Fiqh and its methods and overstepped and exceeded its bounds extensively. Thus, he discussed the limits of knowledge and speculation; how the theory of knowledge was formulated; the necessity of effect from cause, etc. which are exclusively the method of discussions belonging solely to Usulud Din and not Usulul Fiqh".
Now we find that the independence of 'Ilmul Usul as the distinct science of the common elements in the process of deduction to derive the laws of the Shari'ah, and its separation from all other religious sciences from Fiqh to Kalām was not accomplished until after the concept of the common elements in the process of deduction and the necessity of formulating a general system for them had become clearer. This was the reason which helped in distinguishing between the nature of the studies of 'Ilmul Usul and the studies of 'Ilmul Fiqh and Kalām, and led consequently to the setting up of a separate science called 'Ilmul Usulil Fiqh or 'Ilmul Usul.
In spite of the fact that 'Ilmul Usul was able to gain complete independence from 'Ilmul Kalām (the science of theology, there remained in it some conceptual residue, the history of which goes back to the time when the two sciences ('Ilmul Usul and 'Ilmul Kalām) were mixed. This residue continued to be a source of anguish. In that residue was the concept that the narrations termed Akhbār Āhād (single reports) cannot be used as proofs in 'Ilmul Usul, as every proof about it has to be definite and decisive. The source of this concept is 'Ilmul Kalam, because in this science the scholars had laid down that Usulud Din (the basic principles of Islam) require definite and decisive proofs. Thus we cannot prove the Attributes of Allah or the life Hereafter with Akhbār Āhād. The mixture of 'Ilmul Usulud Din and 'Ilmul Usul fiqh and their sharing the word Usul led to the generalization of that concept to apply to 'Ilmul Usul al-Fiqh also. Thus we see that the books on 'Ilmul Usul (i.e. 'Ilmul Usulil Fiqh) up to the time of Muhaqqiq Hilli in the seventh century A.H. continued to criticize proving of the validity of the common elements in the process of deduction with Akhbār Āhād as a departure from the above concept.
We find in the book al-Zari'ah concerning the mingling of Usulul Fiqh and Usulud Din some relatively abstruse and limited conceptions of the common elements in the process of deduction. The author wrote, "You must know that the discussions of Usulu'l Fiqh are in reality discussions about the proofs of Fiqh. In view of what we have described, it is not necessary that the proofs, the methods of arriving at the laws and the existing branches of Fiqh in the books of the jurists, be of the nature of Usul (principles), because the discussions on Usulul Fiqh are discussions on the nature of the proofs by which these Usul establish laws, but not in a detailed manner. The proofs of the jurists are of the same pattern. But their discussions on the sum total are different from those in detail".
This quotation taken from one of the earliest sources of 'Ilmul Usul in the Shari'ah heritage clearly includes the concept of the common elements in the process of deduction, calling them "The proofs of Fiqh (Adillatul Fiqh) in general". It distinguishes between the studies of 'Ilmul Usul and 'Ilmul Fiqh on the basis of the distinction between the proofs of the sum total and the proofs of the details, i.e. between the common elements and the particular elements in our terminology. This means that the concepts of common elements had developed to a great degree by that time. The same concepts found afterwards in the writings of Shaykh Tusi, Ibn Zuhrah, Muhaqqiq Hilli and others. They all knew 'Ilmul Usul as "the science of the proofs of Fiqh in general". Thus they endeavored to express by this the concept of common elements.
In Kitab al-Iddah, Shaykh Tusi says, "Usulul Fiqh" are the proofs of Fiqh. Thus when we discuss these proofs, we discuss in general the obligations, recommendations, permissibility, etc. from different categories. It is not necessary that these proofs should lead to the branches of Fiqh, as the former are proofs on the delineation of the problems and the discussions about the sum total is different from the discussion in detail".
Here the terms "the sum-total" and "the details" are used to denote the common and the particular elements, respectively.
From the above we come to the conclusion that the emergence of 'Ilmul Usul and the intellectual awakening to the common elements in the process of deduction depended on both the development of this process of deduction to a degree of abstruseness and extensiveness and the flourishing and increase in complexity of the thinking of 'Ilmul Fiqh. Thus it was no coincidence that the emergence of 'Ilmul Usul historically followed the appearance of 'Ilmul Fiqh and 'Ilmul Hadith. And that 'Ilmul Usul should develop in the lap of 'Ilmul Fiqh after legal thinking had grown and developed to the extent which permitted the observation of the common elements and their study through the methods of academic research, is again no coincidence. Hence, it was but natural that the concept of common elements should develop gradually and become more abstruse, with the passage of time, until it gained its distinct form and correct limits and was separated from the studies of both 'Ilmul Fiqh and 'Ilmul Usulid Din.
THE HISTORICAL NECESSITY FOR 'ILMUL USUL
The delay in the emergence of 'Ilmul Usul historically, after the appearance of 'Ilmul Fiqh and 'Ilmul Hadith, was not due only to the correlation between the outlook of 'Ilmul Usul and the relatively prior levels of legal thinking. There is also another reason that is of great significance in this regard. It is that 'Ilmul Usul was not found in the capacity of a kind of intellectual luxury, but was the expression of the dire need for the process of deduction for which 'Ilmul Usul was required to supply the indispensable common elements. This means that the need for 'Ilmul Usul originated from the need of the process of deduction for the common elements which are studied and delineated in this science. This need of the process of deduction for the common elements in reality is not an absolute necessity but arose as a historical need.
In other words it was a necessity which was found and which became more severe after jurisprudence had become far removed from the period of the promulgation of the texts, This need was not found to that degree in the jurisprudence contemporaneous with the period of the promulgation of those texts.
To understand this concept clearly, suppose that you were living in the time of the Holy Prophet, in close proximity to him and used to hear the laws directly from him and to understand the texts given out by him owing to their clarity of language and your direct approach to contexts and their expressions. Hence, in such a case would you have been in need, in order to understand the laws of the Shari'ah, for taking recourse to a common element of 'Ilmul Usul like the validity of al-Khabar as a proof, bearing in mind that you either heard the texts directly from the Holy Prophet or they were transmitted to you by persons whom you knew directly and in whose truthfulness you had the least doubt? Or would you have been taken recourse to a common element of 'Ilmul Usul like the validity of al-Zuhur al-'Urfi as a proof, when you were directly and clearly perceiving (with the aid of your sense of hearing) the meaning of the texts issued by the Prophet, whose meaning was not at all doubtful most of the times owing to your knowledge of all the circumstances and contexts of those texts? Or would you have required contemplation to formulate laws to explain abstract (muhmal) statements issued by the Prophet when you were in a position to ask him and seek clarification from him instead of harbouring doubts on those laws? This means that as man was nearer to the period of the promulgation of Islamic law and more conversant with the texts, the less was the necessity for his own judgment regarding general laws and common elements. At that time the formulation of the laws of the Shari'ah would have been completed in a simple manner without jurists having to face numerous gaps and to contemplate filling them through the methodology of the elements of 'Ilmul Usul. However as the jurists became far removed from the age in which the texts were issued, and were forced to rely on history on the historians, on the narrators and the Muhaddithin (traditionalists) in the matter of the transmission of the texts, they faced many gaps and missing links, forcing them to contemplate formulating laws. We may ask; "Was the transmitted text in reality given: by the Prophet or the Imam or did the narrator lie, or did he make a mistake in transmitting it? What did the infallible one mean by this text? Did he indeed intend the meaning I understand from the text when l read it, or did it contain some other meaning according to the circumstances and contexts in which it was issued and of which we are not aware? What does a jurist do when he is unable to find a text on a specific problem? " In this way man becomes in need of the elements of the validity of al-Khabar, or al-Zuhurul-'Urfi; etc. as proofs, from among the laws of 'Ilmul Usul.
This is what we mean by saying that the necessity for 'Ilmul Usul was historical, and connected with the extent of the distance in time of the process of deduction from the age of the promulgation of the Shari'ah and its separation from the circumstances and contexts of the texts of the Shari'ah. It is this separation in time that brings about the gaps and missing links in the process of deduction. It is these gaps that brought about the urgent necessity for 'Ilmul Usul and its laws.
In order to fill up those gaps the need for 'Ilmul Usul was perceived by the first pioneers of this science. Sayyid Jalil Hamza ibn 'Ali ibn Zuhrah Husayn Halabi (d. 585 A.H.) wrote in the first chapter of his book al-Ghunyah: "Since the discussions on the branches of jurisprudence are based on the Usulul Fiqh, it is essential to begin with those Usul and then follow the branches of Fiqh. Any discussion on the branches, of Fiqh, without mastery of the Usul will not be fruitful. However some detractors had objected to it, saying, 'If, concerning the laws of the Shari'ah, you know only a statement of an infallible one, what is the need for 'Ilmul Usul? Your discussions on it seem meaningless and useless".
In this text Ibn Zuhrah connects the need for 'Ilmul Usul with the gaps in the process of deduction by referring to the necessity of the Imamiyah school of thought following the statements of the infallible Imam only. This is because as long as they continue following such statements they have no need for 'Ilmul Usul. This is due to the fact that if the derivation of a law is based directly on the statement of the infallible Imam, then it is a simple task, containing no gaps, which demand contemplation to formulate laws and elements of 'Ilmul Usul to fill them.
In a text of Muhaqqiq Sayyid Muhsin A'raji (d" 1227 A.H.) in his book on Fiqh 'Wasa'ilush Shi'ah", we find a complete awareness of the concept of the historical necessity for 'Ilmul Usul. He spoke about the differences that arose owing to the distance in time from the age of the promulgation of the texts and its being far removed, from it as regards circumstances and contexts. Summing this up, he wrote, "What comparison is there between one favored with nearness in time and one afflicted by being far removed from it, so that they can be termed equals in, riches and poverty? No, there is a world of difference between them. Owing to the length of the period of' separation, the severity of hardships, and the universality of tribulations; what has occurred would have led to a return to the period of Jahiliyah (Age of ignorance), had it not been for Allah and the blessings of His pious servants.
Languages have been corrupted, terminologies and usages changed, the contextual circumstances have disappeared, lies have increased, hypocrisy has spread and contradictions between proofs have become serious so much so that one is almost not able to find a law which is universally agreed upon, owing to the allegations of differences in it. At the same time there is also no one to whom questions may be addressed. Suffice it to say that there is a distinction between the two groups -the contextual circumstances and what is perceived in speaking in detail and in brief. This is different from him who comes across only different narrations and contradictory traditions and needs to apply them to the Qur'an and the known Sunnah: For such an individual preparation, readiness and training in that field are necessary so that he may not make mistakes, because he has to select from the conflicting views".
In the light of this we come to know that the subsequent emergence of 'Ilmul Usul historically was not only the consequence of its correlation with the development of legal thinking and the growth of deduction, it was also the consequence of the nature of the necessity for 'Ilmul Usul. This necessity was historical and was found and developed in direct proportion to the distance in time from the period of the promulgation of the texts.
WORKS ON 'ILMUL USUL
In the light of the preceding, which confirms that the need for 'Ilmul Usul was historical, we are able to explain the separation in time between the heyday of 'Ilmul Usul in the sphere of Sunni legal thinking and its heyday in the sphere of our Imami legal thinking. History indicates that this branch of knowledge relatively thrived and flourished in the sphere of Sunni Jurisprudence before it did so in our Imami Jurisprudence. It is said that 'Ilmul Usul in Sunni theology entered the phase of literary works in the closing stages of the second century (A.H.) when works in that field were written by al-Shāfi'i (d. 189 A.H.) and Muhammad ibn Hasan al-Shaybani (d. 189 A.H.), while we don't find any extensive work on that subject in Shi'ah theology until just after the short occultation i.e.
at the beginning of the fourth century (A.H.). However some essays on various topics of 'Ilmul Usul by companions of the Imams do exist.
We have come to know that the development in the thinking of 'Ilmul Usul was the result of the need for principles in the sphere of deduction, and that this need was historical. This need increased and became more severe as the distance in time from the age of the promulgation of the texts increased. Therefore it was only natural that this separation in time be found earlier in Sunni theology and that Sunni thinking on 'Ilmul Usul should grow and expand before Shi'ah thinking, because Sunni theology claims that the age of the promulgation of texts ended with the death of the Holy Prophet. Thus when Sunni legal thinking crossed the second century, it had become separated from the age of the promulgation of texts by a long period of time which had engendered gaps and missing links in the process of deduction. Thus there was the pressing need for the formulation of general laws of 'Ilmul Usul to cover up the gaps and missing links. As regards the Imamis, however, they were at the time still living in the age of the promulgation of texts of the Shari'ah. This was due to the presence of the Imam as an extension of the stay of the Holy Prophet. Thus the difficulties faced by the 1mami jurists in making deduction were very few; hence, the field did not permit severe necessity for formulating 'Ilmul Usul.
Thus, we find that for the Imamis, the age of the promulgation of texts ended with the beginning of the occultation or with the end of the minor occultation more specifically, their thinking on 'Ilmul Usul only then emerged and they began to study the common elements in the process of deduction. A number of distinguished pioneers from among our jurists established themselves as the leaders in this field, such as Hasan ibn Ali ibn Abi Aqil and Muhammad ibn Ahmad ibn Junayd Askāfi in the fourth century (A.H.).
'Ilmul Usul then quickly entered the stage of literary works. Shaykh Muhammad ibn Muhammad ibn, No'mān known as Shaykh Mufid (d. 413 A.H.) wrote a treatise on 'Ilmul Usul in which he continued the line of thinking followed by lbn Abi Aqil and Ibn Junayd, his predecessors. He criticized both of them for a number of their views. After him came his pupil Sayyid Murtaza (d. 436 A.H.) and he developed this line of thinking on 'Ilmul Usul. On this subject he produced a relatively comprehensive work, which he called al-Zari'ah. In its preface Sayyid Murtaza mentioned that this work was unique in this sphere owing to the trends of 'Ilmul Usul in it, which fully distinguished the Imamis from others. However Sayyid Murtaza was not the only one among the pupil of Shaykh Mufid to have developed this new science and done work in this branch. A number of other students of Shaykh Mufid also wrote on 'Ilmul Usul. Among them was Salār ibn Abdul Aziz Daylami (d. 436 A.H.) who wrote "al-Taqrib fi Usulil Fiqh".
Also among them was the jurist and Mujaddid Shaykh Muhammad ibn Hasan Tusi (d. 460 A.H.) who was recognized as the leader of the jurists after his two predecessors, Shaykh Mufid and Sayyid Murtaza. He wrote a book on Ilmu'l Usul called "al-Iddah fil Usul". Through his efforts 'Ilmul Usul entered a new phase of intellectual maturity, just as with him jurisprudence also entered a higher level of expansion and extension.
In addition to research and studies in 'Ilmul Usul that age also witnessed an extensive effort to collect the traditions transmitted from the Imams of the Holy Prophet's progeny and to assimilate smaller collections of traditions into large and comprehensive ones. And before that age had come to an end, Imami intellectual thinking was enriched by the four comprehensive sources of traditions. These are "al-Kafi" by ThiqatuI Islam Muhammad ibn Ya'qub Kulayni (d. 329 A.H.); "Man la Yahzaruhul Faqih" by Shaykh Saduq Muhammad ibn Ali ibn Husayn (d. 381 A.H.); "al-Tahzib" by Shaykh Tusi (which he wrote in the lifetime of Shaykh Mufid) and also "al-Istibsār" by Shaykh Tusi. These books are called in the terminology of the Imamis "al-Kutub al-Arba'ah (The Four Books).
THE DEVELOPMENT OF THE KNOWLEDGE OF THEORY AND OF ITS APPLICATION BY SHAYKH TUSI
Shaykh Tusi's work on 'Ilmul Usul was not merely as a continuation of the same line of thinking, but it may be considered as a new advancement altogether like a separate part of the extensive development of the whole of legal and intellectual thinking. This pioneering jurist was successfully able to accomplish it. The book 'al-lddah' was an expression of this development on the subject of 'Ilmul Usul, whereas the book "al-Mabsut fil Fiqh" was an expression of the great development in the studies of 'Ilmul fiqh at the level of application, in a manner parallel to the development in 'Ilmul Usul at the level of theory.
As regards the qualitative distinctions between the tendencies in the sphere of knowledge resulting from this new development and the preceding tendencies, we can consider Shaykh Tusi as the separating boundary between the two periods in the history of knowledge -the preparatory era and the era of maturity in knowledge. This pioneering scholar brought the preparatory era to close, and initiated that age of knowledge in which 'Ilmul Fiqh and 'Ilmul Usul became sciences with their own specific intellectual outlooks, their own art, and their own abstruseness.
In this connection perhaps the best pf all possible methods to elucidate the tremendous development which knowledge underwent at the hands of Shaykh Tusi would be to examine two statements written by him- one in the Introduction to his book "al-Iddah" and the other in the Introduction to his book 'al-Mabsut'.
He wrote in the introduction of al-Iddah: " You (may Allah grant you support) have asked for a brief statement on 'Ilmul Fiqh encompassing briefly and concisely all chapters in, accordance with the views of our school of thought and our principles. Whoever has written on this subject has done so along the lines dictated by his own principles (Usul) But none of our companions known to have written on this subjects except Shaykh Abu Abdillah in "al-Mukhtasar", his book on Usulul Fiqh.
However he did not write with complete accuracy because certain irregularities have been transmitted from him and they necessitate rectification and revision. Sayyid Murtaza in most of his discourses had pointed out those irregularities. However, he has not written anything on this subject to which recourse may be taken or which can act as a central pillar to be relied on. Thus you may say, "It is essential to attach the greatest importance to this branch of knowledge because the whole of the Shari'ah is based on it and the knowledge of any aspect thereof is not complete without mastering the principles (of Usul Fiqh). And whoever does not master the principles of Usulul Fiqh can be a storyteller and a layman but not a scholar".
This text of Shaykh Tusi reflects the extent of the importance of the development of Usulu'l Fiqh which he carried out in his book "al-Iddah" and his important role in this field and the importance of what he has derived through research on the formulation of the theories of Usulu'l fiqh within the general religious framework of the Imami school of thought.
This text also re-affirms that Shaykh Mufid was in the forefront of the field of writings on 'Ilmul Usul in the sphere of Imami theology. 1t also shows that Shaykh Tusi wrote "al-Iddah" or at least began writing it during the lifetime of Sayyid Murtaza, as he has prayed in it for the latter's long life. Perhaps, he did not at that time know of the existence of Sayyid Murtaza's book "al-Zari'ah " as he negated the existence of any book on 'Ilmul Usul by the latter. This means that Shaykh Tusi began his book before Sayyid Murtaza wrote "al-Zhari'ah" or that "al-Zhari'ah" had already been written but had not been known or publicized, so that Sayyid Murtaza 's contemporary (Shaykh Tusi) did not know of it when he began writing "al-Iddah".
In his great work on jurisprudence, "al-Mubsut." Shaykh Tusi wrote, "I continue to hear a group of jurists and those associated with the study of jurisprudence who are opposing us, belittling the jurisprudence of our Imami companions and saying, regarding the paucity of branches (Furu ') of jurisprudence and of legal problems. They are the exponents of "insertion" and "competition". Verily those who deny Qiyās (analogy) and ljtihad have no means of solving many of the legal problems and of deriving the branches from the underlying principles (Usul), since the major part of these are based on the two principles of Qiyās and Ijtihad. This statement of theirs reflects ignorance regarding out school of thought and their lack of reflection on our principles. Had these critics only examined our traditions and our jurisprudence, they would have come to know that most of the legal problems mentioned by them are to be found in our traditions based on the authority of the Imams, whose statements, as regards proof, follow the course of those of the Holy Prophet, to specify, generalize, clarify or comment on them. And as for the majority of problems relating to the branches (Furu') of jurisprudence with which their books are replete, there is no branch which is hot dealt with in our principles, and is not found in our school of thought. It is not dealt with on the basis of Qiyās. We follow the principle that to act according to obligatory knowledge is obligatory.
"Acquiring this knowledge is facilitated because it is based on the underlying principle (al-Asl) and on meeting one's obligations etc. In addition, most of the branches of jurisprudence have their origin in the texts transmitted from our companions. However their number has multiplied at the hands of the jurists because of their approach to handle the legal problems, some based on others and their inter-relationships and abstruseness so much so that many of the clear problems have become abstruse owing to this kind of handling even if the problems themselves are familiar and clear.
"For a long time I had a keen desire to write a book covering that field. My desire was aroused but different circumstances interrupted me and other preoccupations kept me busy. Also the lack of desire on the part of this group for such a book and their lack of concern for it, was a setback for my intention. They had written down the traditions and their writings consisted of exact definite words, so much so that if a problem was presented in different words or put forward in a manner other than the usual, they became astonished and were unable to understand it".
"Previously I had written the book "al-Nihayah" in which I had discussed all that was reported by our companions in their writings and all the problems they had dealt with together with their differences thereon. These I arranged in the order of the problems of Fiqh and I collected their views and arranged the books in the given order for reasons explained there. Hence, I did not undertake the branches of the problems nor writing the conclusions of different chapters nor arranging the problems, nor commenting on them, nor reconciling to their differing views. Instead I present all or most of them in the form of quotations, so that they may not have an aversion to that. At the end I wrote brief sentences of conclusion on Ibadāt (acts of devotional worship) in which I preferred brevity and conciseness. I also wrote concluding sentences on the chapters related to Ibadāt (prayers)".
In "an-Nihayah" I promised to write a book especially on the branches of jurisprudence, which, taken, in conjunction with the former, would be complete and sufficient for all intents and purposes. Then I realized that would be incomplete, and to understand it would be difficult for the reader because a branch is understood only when viewed in conjunction with its underlying principle. Thus, I thought it only just that I should write a book encompassing all the works on jurisprudence written so far numbering about thirty and I that I should mention each of them, to the extent that its summarization is possible. These are the works dealing solely with Fiqh and not with invocations or etiquette. I also felt that I should assign chapters, divide the legal problems, reconcile the differing views and treat the matter as exhaustively as possible also that I should deal with most of the branches of jurisprudence mentioned by our opponents, and state the view of our school of thought dictated by our basic principles, after mentioning the underlying principle of every problem.
This book, if Allah grants me the Grace to complete it, will be a work unmatched both among the works of our companions as well as among those of our opponents. This is because I have not come to know so far of any single work by any jurist, which deals with .the underlying principles as well as with the branches of jurisprudence exhaustively according to our school of thought. On the contrary their books, in spite of being numerous, do not encompass the underlying principles as well as the branches of jurisprudence in a single work. As for our companions they have no work on this topic worthy of reference; they give only summaries".
The above quotation expresses the historical circumstances that occurred in the initial stages of the development of legal thinking, through which science of Islamic law expanded and developed in the Imami school of thought until it resulted in the likes of Shaykh Tusi, one of the illustrious scholars who expanded and extended it to a greater and deeper level.
From the above quotation it seems that the legal studies and research that preceded Shaykh Tusi (which he came across and felt anguished thereby) were confined mainly to the review of the traditions and texts. To this, Shaykh Tusi refers as the underlying principles (Usul) of the problems. This review of the data was restricted to the self-same forms that appeared in the original sources of those traditions. Naturally legal research and studies when confined to the underlying principles of the problems, given in a direct manner in the texts, and to the transmitted forms, will be very narrow and restricted with no scope for originality and extension.
In the scales of the development of knowledge, transforming legal thinking from its narrow limited scope dealing with the underlying principles of problems to a wider scope, in which the jurist deals with the branches of Fiqh, with details, with the comparison between laws and with the application of general laws, and also examines the laws of different occurrences and hypotheses in the light of the given data in the texts in these scales, the book "al-Mabsut" was a great and successful endeavor.
From a study of the texts of Shaykh Tusi, the eminent jurist in "al-Iddah" and in 'al-Mabsut", we are able to derive the following two facts: Firstly, 'Ilmul Usul, in the stage of knowledge, which preceded Shaykh Tusi, was proportional to the level of legal research and studies which, at that time, were confined to the underlying principles of problems and the immediate data from the texts of the Shari'ah, and it was not possible for 'Ilmul Usul to develop considerably in that period. This is because the limited need for legal research that confined itself within the limits of the immediate data in the texts of the Shari'ah did not help such a development. Thus naturally, 'Ilmul Usul had to await the expansion and development of legal thinking and its passing through those stages about which Shaykh Tusi felt annoyed and expressed his discontent, Secondly, the development of Ilmul Usul, which Shaykh Tusi presents in his book 'al-Iddah' followed a line parallel to the tremendous development which occurred in that period in the field of jurisprudence. This historical parallelism between the two developments supports the view which we have previously put forward about the interaction between the thinking on 'Ilmul Fiqh and 'Ilmul Usul, i.e., between the studies in theory and practice in the field of jurisprudence. Thus a jurist, who concerns himself with the limits of the meaning of a text and the immediate data either in the same words or in synonymous words, and, who lives at a time not far from that of the infallible ones, will not feel a great need for laws, However when he enters the stage of the branches of that text and the study of details and of putting forward new hypotheses to derive the laws, through whatsoever means, from the texts; he finds himself in great and urgent need of the common elements and the general laws. The wide horizons of legal thinking then open up before him. We must not, however, conclude from the preceding quotations from Shaykh Tusi that the transformation of legal thinking from the stage of being confined to the underlying principles (Usul) of the problems and its Stagnation on the forms of the traditions to the stage of branches and of application of laws, took place suddenly at his (Shaykh Tusi's) hands without any prior preparation. In fact the development that Shaykh Tusi brought about in legal thinking had its seed sown before him by his two illustrious teachers, Sayyid Murtaza and Shaykh Mufid, and before them by Ibn Abi Aqil and Ibn Junayd as we have alluded to previously. Those seeds had their own importance from the point of view of the developments of knowledge, so much so that Abu Ja'far ibn Ma'd Musawi (who came later than Shaykh Tusi) is reported to have come across the book on jurisprudence by fun Junayd called 'al-Tahzib" and to have remarked that he had not come across any book, more excellent, more eloquent, with better expression or with a more delicate meaning than that. This book deals with the branches of jurisprudence as well as the underlying principles, and shows differences in the problems and cites proofs, both according to the way of the Imamis as well as according to the way of their opponents. This testimony demonstrates the value of the seeds that grew until they bore fruit at the hands of Shaykh Tusi.
Then came Shaykh Tusi's book "al-Iddah', which represented the development of the thinking on 'Ilmul Usul as the fruit of those seeds, in compliance with the needs for extension and expansion in the legal research and studies. In this light we come to know that it is an error to say that the book "al-Iddah " severed the relationship between the development of 'Ilmul Fiqh and that of 'Ilmul Usul and established the possibility of .the development of the thinking on 'Ilmul Usul to a considerable extent without thinking on science of jurisprudence. This is because Shaykh Tusi wrote "al-Iddah" in the lifetime of Sayyid Murtaza and at that time thinking on science of jurisprudence was in its initial stages and did not develop except in the book "al-Mabsut" which the learned Shaykh Tusi in the latter part of his life the reason why making such a statement is an error is that though the book "al-Mabsut" was chronologically younger than "al-lddah", yet the former only embodied the extension and expansion of legal thinking which had begun to develop and branch out at the hands of Ibn Junayd, Sayyid Murtaza, etc,