Öz
The evidential value of khabar al-wāhid was one of the important issues in Islamic legal theory. It has been intensely discussed among theologians (Muʿtazila), fiqh scholars and hadith scholars since the 2nd/8th century. Many scholars from these schools joined in the discussion in their works that either deny or defend the evidential value of khabar al-wāhid. Abū Alī al-Jubbāī (d. 303/916), the leading name of the Basra Muʿtazila school, was one of those who put forward a different view on the subject criticizing the opinions and evidence presented before him; probably in his nonextant work named Kitābu’l-akhbār. Jubbāī firstly criticized the evidence produced about the evidential value of khabar al-wāhid, which means the report of a single person. As a result of our comparisons, we found that the evidence which al-Jubbāī criticized is the same evidence used by Shaybānī (d. 189/805), Shāfi‘ī (ö. 204/820), Īsā b. Abān (d. 221/836) and Bukhārī (d. 256/870) before him about the authority of khabar al-wāhid. Secondly, al-Jubbāī argued that khabar al-wāhid which does not reach the level of tawātur should be transmitted at least from two transmitters in order to be evidence and tried to justify this with various arguments. In this study, we elaborated on his views concerning the subject and revealed how they were understood in the tradition of legal theory. al-Jassās (d. 370/981) who lived two generations after al-Jubbāī, reported these criticisms in al-Fusūl, and tried to respond to them. He probably knew al-Jubbāī’s Kitābu’l-akhbār and used it. However, al-Jassās did not explicitly mention the name of the person; he only criticized and conveyed his views and evidences and referred to him as "some people of knowledge". As a result, we reached the conclusion that the one whom al-Jassās refers to here is al-Jubbāī.