The number of traditions in al-Kafi is 15...

The number of traditions in al-Kafi is 15,181;[^8] according to another reckoning 15,176.[^9] If the traditions reported in different sections are counted, the number is over 1,000 more. Of the basic traditions, 5,072 are considered sound (sahih) by scholars, i.e.

first category; 144 are regarded as good (hasan), second category; 178 are held to be trustworthy (muwaththaq), third category; 302 are adjudged to be strong (qawi), fourth category; and 9,484 are considered weak (da'if), fifth category.[^10] The fact that a tradition is considered weak does not mean that it is not true.

What it means is that the scholars of tradition have found some weakness in the tradition, usually one of the persons in the isnad, which suggests the possibility that the tradition might not go back to the Imam as claimed.

The science developed by Islamic scholars of tradition in order to examine the isnads and subject matter of traditions is a very specialised study; it involves, in particular, `ilm al-rijal, the study of the backgrounds of individual traditionists who have handed on the tradition. The usul of al-Kafi are divided into eight kutub or chapters and most of the kutub are divided into abwab or sections. The eight kutub are. Kitab al-'aql wa-'l'jahl, "The Chapter of Reason and Ignorance".

This chapter presents the theological distinction between reason and ignorance. Kitab fadl al-'ilm, "The Chapter of the Excellence of Knowledge". In this chapter knowledge ('ilm) is dealt with on the basis of its basic early Islamic meaning of the traditional knowledge of Islam, i.e. knowledge of religion that has been passed on and inherited.

In the course of this chapter, sections deal with the methods of approaching Islamic traditional knowledge; the methods of judging the truth of the subject matter of traditions, a description of traditions from the Imams and arguments against the use of personal opinion (ra'y) and analogy (qiyas). 3. Kitab al-tawhid, "The Chapter of Unity". This, as its name suggests, deals with the theology of God. Kitab al-hujja, "The Chapter of the Proof".

This deals with the need for man and the world to have "a proof". That "proof" is the Imams, and before them it was the prophets. It also includes an historical section on the Imams. Kitab al-Iman wa-'l-kufr, "The Chapter of Faith and Unbelief". This is a comprehensive survey of the elements of faith (iman) and unbelief (kufr).