Among the debates conducted in Islamic intellectual circles in the early ʿAbbāsid period, one of the most significant was the debate about the nature of value. To simplify the situation a little, we may say that two main theories opposed each other. One was that of the Muʿtazilites, that values such as justice and goodness have a real existence, independent of anyone's will, even God's: this view is classed as ‘objectivism’. The other theory was that of Ashʿarī and his like, that all values are determined by the will of God, who decides what shall be just and so forth: this will be called ‘theistic subjectivism’. Following a struggle between the two doctrines, that of Ashʿarī finally prevailed in most learned circles of classical Sunnite Islam, a result which had far-reaching consequences in law and other spheres of Islamic civilization. As far as the writer is aware, no one has yet examined as a separate problem the reasons why the Ashʿarite theory of value prevailed.

The primary philosophical question about value can be stated broadly thus: What is the common element in all that is called ‘good’, ‘right’, etc.? This question includes the more specific ones of ethics: What constitutes a right action? and, How do we know the right action?