The present study examines the concepts of istiṣlāḥ, munāsaba and maqāṣid aš-šarʿ in the thought of Abū Ḥāmid al-Ġazzālī (d. 1111 C.E.). Ġazzālī’s treatise on legal hermeneutics, the Kitāb al-Mustaṣfā, is the earliest extant source containing a systematic discussion of those concepts. In Ġazzālī’s hermeneutical system, the three concepts are closely interrelated: He uses them as a conceptual frame to discuss the role and scope of human value judgments in determining God’s legal command. Ġazzālī claims that, in principle, it is legitimate for Man to draw on human notions of good and evil in order to interpret God’s legal revelation. However, Ġazzālī also establishes the epistemological limits of human value judgments. He discusses various hermeneutical operations that involve such value judgments and carefully distinguishes between legitimate operations and others that – in Ġazzālī’s opinion – are methodologically unsound as they result in a mere projection of human value judgments onto God’s legal command.