In this monograph, Hassan Ansari and Amin Ehteshami provide a synoptic examination of epistemological discussions concerning the authority of scriptural sources (akhbār) in Shiʿi jurisprudence during the third to sixth centuries AH. Seeking Certitude: Scriptural Authority in Early Shiʿi Jurisprudence provides the first book-length study of this under-examined topic of the Shiʿi intellectual tradition. Through close readings of primary texts, the authors trace and evaluate the views of the period’s most prominent thinkers such as al-Kulaynī, Ibn Junayd al-Iskāfī, Ibn Bābawayh, al-Mufīd, al-Ṭūsī, Ibn Zuhra al-Ḥalabī, and Ibn Idrīs al-Ḥillī. The subjects discussed include the developments of Shiʿi legal theory during the third/ninth to sixth/twelfth centuries; various ways of conceptualising what constitutes a ‘scriptural’ source; justifications offered for including the reports attributed to the Prophet and the Imams as the second most authoritative source of law after the Qurʾan; frameworks elaborated for evaluating the authenticity of scriptural sources; epistemological discussions regarding the reliability of historical reports in general and scriptural reports in particular; solutions proposed for resolving disagreeing and contradictory reports; and the legitimacy of using a scriptural report of uncertain origins as evidence for determining a legal ruling as binding. This book will be of interest to students and scholars in Islamic law and legal theory, theology, scriptural hermeneutics, medieval intellectual history, and Islamic studies.