Moojan Momen: An introduction to shī i Islam: the history and doctrines of Tweler Shī ism. xxii, 397 pp., 40 Plates. New Haven and London: Yale University Press, 1985. £18.50.Said Amir Arjomand: The Shadow of God and the Hidden Imam: religion, Political order, and social change in Shī ite Iran the beginning to 1890. (Publications of the Center for Middle Eastern Studies [Chicago], No. 17. ) xii, 356 pp. Chicago and London: University of chicago Press, 1984. £24.80.