and giving less is forbidden injustice. Repaying evil in kind is permissible justice; exceeding it is forbidden, while exacting less is a recommended act of kindness. Thus, injustice belongs to the wrongdoer, justice to the one who takes a middle course, and recommended kindness to the one foremost in good deeds.

The community comprises three categories: one who wrongs himself, one who takes a middle course, and one who is foremost in good deeds. Jurists often find it difficult to determine precisely what constitutes fair compensation, in both kind and amount, and disagree over this in many cases. This is because it varies according to places, times, circumstances, the consideration given, what is received in return, and the parties to the exchange.

We therefore say: “Fair compensation” is the equivalent of the consideration customarily stipulated, known as the price and the customary rate. The consideration stipulated in contracts is of two kinds: one that people habitually use and recognize, which is the familiar, customary compensation; and another that is exceptional, arising from intense desire, an intention to cause harm, or other factors.

Fair compensation is also called the “fair price” and the “equivalent,” because it corresponds to the equivalent of the item itself and is then assessed at the price of its like. Its basis is therefore people’s choice, will, and desire.

For this reason, many scholars have said: “Fair value is what a thing is worth in the estimation of those who desire it.” The qualification “under customary circumstances” must be added. Its basis, then, is people’s will and desire. Reason establishes that a thing is to be treated like its equivalent. This belongs to the justice, analogical reasoning, comparison, and drawing of parallels that Allah has made innate in His servants.