Meaning of Hadith & Traditions
In works on Islam, the word "hadith" usually refers to the sayings or "traditions" which have been transmitted from the Prophet. Muslims hold these to be the most important source of Islamic teachings after the Qur"an. Numerous works have been written in Western languages on the role of thehadith literature in Islam and a number of important translations have been made. But almost all Western studies have been limited to the point of view of Sunni Islam and based on Sunni sources and collections. Practically no one has paid any serious attention to the different nature of thehadith literature in Shi"ism and the different sources from which thehadiths are derived.
The fundamental distinction to be made between Shi"ite and Sunnihadiths is that in Shi"ism the traditions are not limited to those of the Prophet, but include those of the Imams as well. As important and basic as this point is, it has not been understood even in such standard reference works as the newEncyclopedia of Islam. There, the author of the article "Hadith" is aware that there is some difference between Shi"ism and Sunnism on the question of whichhadiths are included, but he thinks that it lies in the fact that the Shi"ite collections accept "only traditions traced through "Ali"s family." But this is incorrect, since numerous traditions are also transmitted through other sources. What the author fails to mention is that thehadith literature as understood by Shi"ites is not limited to the sayings of the Prophet, but includes those of the Imams as well.
In short, collections ofhadiths in Sunni Islam, such as those of al-Bukhari and Muslim, contain only sayings transmitted from and about the Prophet. But the Shi"ite collections, such as that ofal-Kulayni, also contain sayings transmitted from and about the twelve Imams. Naturally the Shi"ites make a distinction among thehadiths, so that those transmitted from the Prophet are of greater authority, but nevertheless all traditions are listed together according to subject matter, not according to author.
Despite the vast amount of scholarship carried out by Western orientalists since the nineteenth century and the analyses and translations made of various Islamic sources, very little attention has been paid thus far to the collection of religious sayings, sermons, prayers, proverbs and didactic expositions which comprises the corpus ofHadith as understood by Twelve Imam Shi"ite Muslims. It is of course true that much of the substance of the Shi"itehadith collection resembles the Sunni collection, 
and to the extent that the latter has been studied the former has also been dealt with in an indirect manner. But in as much as Shi"itehadiths possess a form, style and "perfume" of their own, no indirect treatment of their substance and content can replace the direct translation and analysis of this collection itself.
It is in fact rather amazing that despite the extreme importance of Shi"itehadith for the development of Shi"ite law and theology as well as many fields of the "intellectual sciences" (al-"ulum al-"aqliyyah), not to speak of its role in piety and the spiritual life, the sayings of the Imams of Shi"ism have not been rendered into English until now. Nor have they been studied as a whole and as a distinct body of religious writings of an inspired nature within the general context of Islam itself. The Shi"itehadith literature includes all the sayings of the Prophet of Islam accepted by Shi"ites as well as the traditions of the twelve Imams from "Ali ibn Abi talib to the Mahdi. This collection is thus considered to be, after the Holy Quran, the most important body of religious texts for Shi"ites. As in Sunni Islam, so in this case: theHadith forms along with the Revealed Book the basis of all the religious sciences, including of course theShari"ah as well as religious life in both its intellectual and devotional aspects. No aspect of the life and history of the Shi"ite community would be comprehensible without a consideration of this body of inspired writings. In Sunni Islam,Hadith is limited to the sayings of the Blessed Prophet. In fact to use the term "hadith" in Sunnism is to refer to his sayings and not to anyone else"s. In the case of Shi"ism, however, although a clear distinction is made between propheticHadith (al-hadith al-nabawi) and the sayings of the Imams (al-hadith al-walawi), the two are included in a single collection. This means that from a certain point of view the apostolic age of Islam is seen by Shi"ism to stretch way beyond the relatively short period usually associated with apostles in various religions.
The reason for this perspective lies of course in the Shi"ite conception of the Imam. 
The term imam as used in a technical sense in Shi"ism differs from the general usage of the term in Arabic, where it means "leader", or in Sunni political theory where it means the caliph himself. As used technically in Shi"ism the term refers to the person who contains within himself the "Muhammadan Light" (al-nur al-mahammadi) which was handed down through Fatimah, the daughter of the Blessed Prophet, and "Ali, the first Imam, to the others, terminating with the Hidden Imam who is to appear again one day as the Mahdi. 
As a result of the presence of this light, the Imam is considered to be "sinless" (ma"sum) and to possess perfect knowledge of the esoteric as well as the exoteric order.
The Imams are like a chain of light issuing forth from the "Sun of Prophecy" as an extension of the propheticHadith, just as the light of their being is seen as a continuation of the prophetic light. In Shi"ite eyes, the temporal separation of the Imams from the Blessed Prophet does not at all affect their essential and inner bond with him or the continuity of the "prophetic light" which is the source of his as well as their inspired knowledge.
This metaphysical conception is the reason that Shi"ites incorporate traditions stretching over two centuries into a single whole with those of the Blessed Prophet himself. It also distingiushes the Shi"ite conception ofHadith from that held in Sunnism. Otherwise, the actual content ofHadith in Sunni and Shi"ite collections is very close. After all, both kinds concern the same spiritual reality. Of course the chain of transmission accepted by the two schools is not the same. But despite this difference in the authorities who have handed down the prophetic sayings, the actualhadiths recorded by Sunni and Shi"ite sources have overwhelming similarities. The major difference is the Shi"ites" consideration of the extension of an aspect of the being of the Blessed Prophet in the Imams and therefore their addition of the sayings of the Imams to the strictly "prophetic"Hadith.
The sayings of the Imams are in many ways not only a continuation but also a kind of commentary and elucidation of the propheticHadith, often with the aim of bringing out the esoteric teachings of Islam. Many of these hadiths deal, like those of the Blessed Prophet, with the practical aspects of life and theShari"ah. Others deal with pure metaphysics, as do certain prophetichadiths, especially the "sacredhadiths" (hadithqudsi). Still other sayings of the Imams deal with the devotional aspects of life and contain some of the most famous prayers which have been recited over the ages by both Sunnis and Shi"ites. Finally some of the sayings deal with the various esoteric sciences. They thus cover a vast spectrum ranging from the "mundane" problems of daily life to the question of the meaning of truth itself. Because of their innate nature and also the fact that like Sufism they issue from the esoteric dimension of Islam, they have intermingled over the ages with certain types of Sufi writings. 
They have also been considered as sources of Islamic esotericism by the Sufis, because the Imams of Shi"ism are seen in the Sufi perspective as the spiritual poles of their age. They appear in the spiritual chain (silsilah) of various Sufi orders, even those which have spread almost exclusively among Sunnis. 
Because of the nature of their contents, these sayings have influenced nearly every branch of Shi"ite learning as well as the daily life of the community. Shi"ite jurisprudence (fiqh) bases itself directly upon this corpus in addition to the Holy Quran. Shi"ite theology (kalam) would be incomprehensible without knowledge of these sayings. Shi"ite Quranic commentaries draw heavily upon them. Even sciences of nature such as natural history or alchemy were developed with reference to them. And finally these sayings have surfaced as sources for meditation of the most sublime metaphysical themes over the centuries, and some of the most elaborate metaphysical and philosophical schools of Islam have issued to a large extent from them. Later Islamic philosophy as associated with the name of Sadr al-Din Shirazi, would in fact be inconceivable without recourse to the Shi"itehadith collection. 
One of Sadr al-Din"s greatest metaphysical works is his unfinished commentary upon a portion of the most important of the four basic Shi"ite collections of Hadith, theal-Kafi of al-Kulayni. 
Within the collection of Shi"itehadiths are certain works which need to be mentioned separately. There is first of all the celebratedNahj al-balaghah (The Path of Eloquence) of "Ali ibn Abi talib assembled and systematized by the fourth/tenth century Shi"ite scholar Sayyid Sharif al-Radi. Considering the enormous importance of this work in Shi"ite Islam as well as for all lovers of the Arabic language, it is remarkable how little attention has been paid to it in European languages. 
After all, many of the leading writers of Arabic such as Taha Husayn and Kurd "Ali claim in their autobiographies to have perfected their style of writing Arabic through the study of theNahj al-balaghah, while generation after generation of Shi"ite thinkers have meditated and commented upon its meaning. Moreover, the shorter prayers and proverbs of this work have spread very widely among the populace and have entered both the classical and folk literature of not only Arabic but also Persian, and through the influence of Persian, several other languages of the Islamic peoples, such as Urdu.
TheNahj al-balaghah contains, besides spiritual advice, moral maxims and political directives, several remarkable discourses on metaphysics, especially concerning the question of Unity (al tawhid). It possesses both its own method of exposition and a very distinct technical vocabulary which distinguish it from the various Islamic schools which have dealt with metaphysics.
Western scholars refused for a long time to accept the authenticity of the authorship of this work and attributed it to Sayyid Sharif al-Radi, although the style of al-Radi"s own works is very different from that of theNahj al-balaghah. In any case as far as the traditional Shi"ite perspective is concerned, the position of theNahj al-balaghah and its authorship can best be explained by repeating a conversation which took place some eighteen or nineteen years ago between "Allamah Tabatabai, the celebrated contemporary Shi"ite scholar who is responsible for the selection of the present anthology, and Henry Corbin, the foremost Western student of Shi"ism. Corbin, who himself was as far removed from "historicism" as possible, once said to "Allamah Tabataba"i during the regular discussions they had together in Tehran (in which the present writer usually acted as translator), "Western scholars claim that "Ali is not the author of theNahj al-balaghah. What is your view and whom do you consider to be the author of this work ?" "Allamah Tabataba"i raised his head and answered in his usual gentle and calm manner, "For us whoever wrote theNahjal-balaghah is "Ali, even if he lived a century ago."
The second notable work in the Shi"ite collection ofHadith is the al-Sahifat al-sajjadiyyah (The Scroll of al-Sajjad of the fourth Imam Zayn al-"Abidin), also called al-Sajjad. A witness to the tragedy of Karbala-which must have left an indelible impression upon his soul-the fourth Imam poured forth his inner life in a symphony of beautiful prayers which have caused theSahifah to be called the "Psalms of the Family of the Holy Prophet". These prayers form a part of the daily religious life of not only Shi"ites but also Sunnis, who find them in many of the prayer manuals most popular in the Sunni world. 
Also notable in the Shi"ite collection ofHadith are the sayings of the fifth, sixth and seventh Imams, from whom the largest number of traditions have been recorded. These Imams lived at the end of the Umayyad and beginning of the Abbasid dynasties when, as a result of the changes in the caliphate, central authority had weakened and the Imams were able to speak more openly and also train more students. The number of students, both Shi"ite and Sunni, trained by the sixth Imam Ja"far al-Sadiq has been estimated at four thousand. He left behind a vast body of sayings which range from the field of law to the esoteric sciences.
The sayings of the Holy Prophet and the Imams have been of course a constant source of meditation and discussion by Shi"ite men of learning throughout the ages. But it is especially in the later period of Shi"ite history beginning with Sayyid Haydar Amuli, leading to the great masters of the Safavid period such as Mir Damad and Mulla Sadra and continuing to the present day that these sayings have served as a distinct source for metaphysics and philosophy as well as the juridical and Quranic sciences. The commentaries of Mulla Sadra, Qadi Sa"id al-Qummi and many others on these collections of Shi"iteHadith are among the great masterpieces of Islamic thought. 
Later Islamic philosophy and theosophy in fact could not be understood without them. 
Seyyed Hossein Nasr
There are six canonical collections in Sunni Islam which have been accepted by the whole community since they were first compiled in the second and the third Islamic centuries. These collections, referred to al-Sihah al-sittah, theSix Correct Collections, are associated with the names of great scholars ofHadith such as Bukhari, Muslim, etc. Of these, the most famous is that of Bukhari, which has been translated into English (Sahih al-Bukhari:Arabic-English, by Muhammad Muhsin Khan, Islamic University, Madina; second revised edition, Ankara, 1976). The vast concordance ofHadith by Wensinck, Mensing et al. (Leiden, 1936-69) is based on these six collections. 
See "Allamah Tabatabai,Shi"ite Islam, London-Albany, 1975, pp. 173ff. 
As far as the continuity of the chain is concerned the Isma"ili conception is of course different, since for the Isma"ilis the chain of Imams continues un-interrupted to this day. 
On the relation between Shi"ism and Sufism See S. H. Nasr,Sufi Essays, London, 1972, pp. 104-20 
A most interesting example of such interpenetration is to be seen in part of the famous prayer of the third Shi"ite Imam Husayn, also found in Shadhili prayers manuals. See W. Chittick, "A Shadhili Presence on Shi"ite Islam",Sophia Perennis, vol. I, 1975, pp. 97-100 
On this corpus as a source for the doctrines of Sadr al Din Shirazi see S. H. Nasr,Sadr al Din Shirazi and His Transcendent Theosophy, London-Boulder, 1978, chapter 4. 
This monumental work was translated into French by H. Corbin, who taught it for many years in Paris, but it has never been published. See Corbin,En Islam iranien, Paris, 1971. 
This work has been translated several times in part or wholly in the Indo-Pakistani sub-continent and in Iran, but none of these translations is completely adequate. A new translation as been prepared by S. H. Jafri which is supposed to be published soon and which, we hope, will fulfill the very difficult condition of doing justice to both the meaning and the literary beauty of the text. 
Some of these prayers have been translated by C. Padwick in herMuslim Devotions, London, 1961 
See H. Corbin,En islam iranien.
 Not only Mulla Sadra, but also his students were deeply influenced by this collection. One of Mulla Sadra"s most famous students, Mulla Muhsin Fayd Kashani, who was at once theologian, gnostic and philosopher, was also an outstanding authority on Shi"iteHadith. Hisal-Wafi is one of the most studied works onhadiths of the Shi"ite Imams and their lines of transmission.