Kitab al-Tadhkirah bi Usul al-Fiqh

The science of Usul al-fiqh constitutes the code of juristic deduction. It consists of a method for deriving practical rules from reliable sources. The formulation of the rules of jurisprudence amounts to laying down a code for the practice of fiqh. Without such a code, the practice of fiqh lacks a well-defined framework and is prone to error, confusion, and incursion of foreign elements, as a result of which the rules deduced would lack credibility. Moreover, without such a code, subjective opinion and personal understanding and taste of the legist affects the results obtained to an inordinate extent and juristic opinion becomes subject to divergence and chaos.

  is true that the growing sophistication and maturity of usul al-fiqh isconducive to the soundness of juristic opinions; but that which has a critical relevance for the results of juristic effort is the creation of this discipline. Without doubt, the real roots and sources of usul al-fiqh are implicit in the formulations of the Imams, may peace be upon them, which are referred to as usul mutlaqat, but the first work on usul amongst the Shi'ah (so far as we know) was written by al-Shaykh al-Mufid. It is a small book but rich in content, entitled al-Tadhkirah bi usul al-fiqh, which is probably an abridgement made by al-Shaykh Abu al-Fadl al-Karajaki (d. 44911057), al-Mufid's pupil, of the master's work, which was itself a short work.

  its briefness, this work has considerable importance because, firstly, it is the first work on Shi'ite usul al-fiqh. In the introduction to his`Uddat al-'usul, al-Shaykh al-Tusi says: "We do not know of anyone from amongst our companions having written anything on this subject (fihadha al-ma'na) except that which our teacher Abu `Abd Allah-may God's mercy be upon him-has mentioned in his short work (al-mukhtasar) on usul al-fiqh. 

 , many topics are dealt with in it in a concise manner and especially in the chapter relating to semantics?' (mabahith al-'alfaz) there are several section headings covering important topics. Thirdly, the opinions of al-Mufid on some of the topics discussed in it are very similar to those of much later scholars of usul. For instance, his statement concerning khass and 'amm (general and particular) resembles very much what latter-day scholars close to our own age mean by al-'iradat al-jiddiyyah and al-'iradat al-'isti'maliyyah. In this context al-Mufid says (p. 37):

 , though the book was meant to be a short one,  the topics which are of greater relevance and need for the deduction of juristic rules have been given priority in the book, and other topics of theoretical interest (such as those related to the nature of knowledge and language, which the Shaykh al-Ta'ifah-may God's mercy be upon him-has discussed in detail at the beginning of the `Uddat al-'usul) have not been dealt by him. In view of this it is very interesting that in spite of the book's conciseness, some topics which are of frequent use and reference in legal inference have not been neglected but discussed in an appropriate manner. Some of these topics are: the applicability of the concepts of `umum anditlaq only to verbal Sunnah (al-sunnat al-qawliyyah), not to behavioural Sunnah (al-sunnat al-fi'liyyah);  that a command (amr) subsequent to a prohibition does not signify anything more than permissibility (ibdhah);[  that when an exception is made subsequent to several commands, in the absence of an indication the exception applies to all those instances.

  that which has been said it becomes clear that al-Shaykh al-Mufid, through his book on usul al-fiqh prepared the necessary ground for the development of a scientific model for juristic inference. For him `ilm al-'usul is not a collection of quasi-theological notions, but, as mentioned expressly by his pupil in 'Uddat al-'usul, it is "the basis on which the laws of the Shari'ah are based. The knowledge of the Shari'ah does not become perfect without making this basis strong, and one who fails to acquire a firm knowledge of jurisprudence is only a narrator." That is, such a person is an imitator, not a true scholar.