This is a discussion of the theory of intent in Islamic law. In an extended example, I focus on the doctrinal views of Zaydī school jurists from Yemen, but I also indicate that the issues and the analytic distinctions characterize the Sunnī schools as well. As in western law, ascertaining intent is fundamental to applied Islamic legal analyses in sharī'a courts, in matters ranging from contracts to criminal cases. My discussion here, however, is limited to the doctrinal theory of such intent-based legal analyses, about which the Muslim jurists, including the Yemeni jurists of my extended example, hold divergent opinions. Following the Yemeni jurists in their analyses, I consider the relation of intent and manifest expression, including words and writings, across the different domains of bilateral and unilateral acts.