The Muslim academic Jonathan Brown gives the following thought provoking answer.
This question strikes at the root of the incongruity between modern law and how many view the Shari'a. Although it seems obvious and, indeed, essential to many today, the notion that a legal system should function as a routinized and efficiently ordered machine stripped of cultural fictions and traditions is fairly new. It is a product of legal reforms envisioned by modernists like the English philosopher and jurist Jeremy Bentham (d. 1832).
Prior to the comprehensive legal reforms in American and British law from the mid nineteenth century to the mid twentieth, having laws on the books that were not intended to be applied was normal. In fact, it's still a feature of law today in the US. How many times do we see signs warning us that littering will be punished by a maximum fine of $1000? How many of us know anyone who has been fined $1000 for littering? How many college students are allowed to drink under the age of 21?
To quote the conservative legal scholar Robert George and also Paul of Tarsus, law is our teacher. It is not just a means of resolving disputes or maintaining order. It is a statement by authoritative voices within a society of how that society should be.
