Classical Muslim and modern historians of Islam have generally recognized the Imām al-Ḥaramayn Abu l-Maʿālī al-Juwaynī (a.d. 1028–85) as an important transitional theologian between the older Ash'arite kalām and the via moderna of Ghazālī and his successors. The Arabic texts of his main surviving works have been published, as well as translations of some into western languages. Careful attention has been given to him in modern studies of kalām such as those of L. Gardet, G. Anawati and M. Allard, although no one has yet written an exclusive monograph of book size on him, as he deserves. This article is devoted to one aspect of his ethical thought, which has escaped treatment until now.

The aspect to be dealt with here is the fundamental question of the nature of value in its application to action. In classical Islam the main issue was whether value terms such as ‘good’, ‘evil’, ‘obligatory’ are definable only by relation to the commands and prohibitions of God, or whether they have objective meanings of their own, which can be applied even to God's actions. This question was much discussed, sometimes as one of the later topics of theology, after the unity and other attributes of God, and sometimes as a foundation for jurisprudence, since the nature of these concepts is basic for understanding how the jurist must describe the sources of Islamic law and how he must construct his theory of legal knowledge.