Analyses the introduction of Yeshuʿah ben Yehudah’s Risāla fī ’l-Jawāb ʿan masāʾil mushkila fī ’l-tarkīb, its key concept (al-muwāḍaʿa al-sharʿiyya), and its relation to Muʿtazilī uṣūl al-fiqh.