How do you compare two things with no common qualities? His conclusion: it can only be done by comparing both to a third thing with no qualities at all. For this reason, he explains, God created dinars and dirhams, coins made out of gold and silver, two metals that are otherwise no good for anything:
Important note! Al-Ghazali's interpretation of why metals-backed currencies were desired is not because the metals themselves had some intrinsic value, but that their value was actually from their lack of intrinsic value - instead, based on the underlying value of the goods, services and debt (credit) being transacted with them.
