This is the second of three volumes reprinting the collected papers on Islamic subjects by Richard M. Frank, Professor Emeritus at the Catholic University of America. It brings together Franks’s articles on early kalam, the Mu`tazilites, and the development of the thought of al-Ash`ari. The studies in this collection are of particular importance for the study of kalam, in that they represent an original attempt to make philosophical sense and understand the theoretical underpinnings of the foundational theological tradition in early Islam, the Mu`tazilite school of Basra. They focus, among others, on Abu l-Hudhayl al-`Allaf, al-Jubba`i, and al-Ash`ari, and include a critical edition and translation of the latter’s al-Hathth `ala l-bahth.