Politically, it was as the ideological wellspring behind the self-styled 'Islamic Revolution' of 1979 that Shi'ism first came to world attention, garnering for itself a reputation as an alien, militant and anti-Western force responsible - directly or indirectly - for the lion's share of the unrest in the Muslim world ever since. Its geo-strategic significance is considerable: given that most of the world's 150 million Shi'ites live in areas with the world's largest deposits of oil, the importance of Shi'ism as a cultural and religious force far outweighs the number of its adherents. And from a purely religious point of view, the influence of Shi'ite law, theology and cultic practice on the development of Islam in general, and on several key Muslim civilisations in particular, is inestimable. Nevertheless, Shi'ism remains a largely unknown entity outside its natural constituencies, with few scholarly works devoted in their entirety to its history, beliefs and practices. 'Critical Concepts: Shi'ism' seeks to redress this imbalance. The four volumes of this set bring together some of the most significant modern and pre-modern contributions to the study of Shi'ism, giving readers access to material that has hitherto been scattered and often difficult to locate. While the lion's share of the material stems from the past fifty years, classic studies from earlier periods have been included, thus providing insight into the developmental dynamics of the field. Drawn from a wide range of journals, research monographs, occasional papers and edited volumes, the articles that comprise this collection reflect the increasingly interdisciplinary nature of Shi'ite studies as it stands today. An introductory essay at the beginning of the first volume draws together the thematic strands and places each article in its broader context.