The Islamic finance industry has often battled with the question: How Islamic is Islamic banking?
The question's pertinence was raised in March last year, when Sheikh Muhammad Taqi Usmani, of the Accounting and Auditing Organization for Islamic Finance Institutions (AAOIFI), a Bahrain-based regulatory institution that sets standards for the global industry, said that 85% of Sukuk, or Islamic bonds, were un-Islamic.
Usmani is the granddaddy of modern-day Islamic finance, so having him make this statement is synonymous with Adam Smith saying that free-markets are inefficient.
Because Sukuk underpin the modern-day Islamic financial system, one of its pre-eminent proponents arguing that the epicentre of the system was flawed sent shockwaves through the industry.
It also gave ammunition to the many critics who see Islamic finance as an industry more driven by cultural identity than practical problem solving: as a hodgepodge of incoherent, incomplete, impractical and irrelevant ideas.
The products that modern-day Islamic bankers have created are very similar to conventional products.
So similar, in fact, that to an outside observer they could be considered the same.
Islamic banks now offer Islamic mortgages, Islamic car loans, Islamic credit cards, Islamic time deposit and guaranteed return accounts, Islamic insurance and some even offer Islamic managed and hedge funds.
This point is conceded by Samir Alamad, Sharia, or Islamic law, compliance and product development manager of the Islamic Bank of Britain.
"The industry does not want to alienate its products," he says.
"They have to be recognisable, produce the same outcome as conventional products, but remain within the guidelines of Sharia."
The core of Islamic economics is a prohibition on interest.
This immediately creates a problem for Islamic banks, as conventional banks charge borrowers an interest rate through which they can reward their depositors and make some profit for being the broker.
With interest ruled out it is harder to make money.
The modern Islamic banker has found a way around this prohibition, however.
As in many Islamic products, the bank enters a partnership with its depositors and invests his money in a Sharia compliant business.
The profit from this investment is then shared between the depositor and the bank after a set time.
In many cases this "profit rate" is competitive with the conventional banking system's interest rate for savers.
Alternatively, an Islamic banker might enter into a lease agreement for a car or a house with an individual.
The bank would buy a vehicle outright and then lease it back to the person who wanted it, over a time period that would ensure that the capital was repaid and the bank made a profit.
Alternatively the bank would enter into a partnership with a person wanting to buy a house. The bank would buy 70% of the house, the individual 30%.
The bank then rents its share of the house back to the individual until the house is fully paid for.
The bank makes a profit on the rent, which would be higher than equivalent rents in the area, but on an annualised percentage basis, would look very much like a conventional mortgage interest rate.
To the casual observer, a spade is a spade.
Whether the product is dressed up in Arabic terminology, such as Mudarabah, or Ijarah, if it looks and feels like a mortgage, it is a mortgage and to say anything else is semantics.
The potential wealth locked up in oil-rich Gulf states encouraged the conventional banks to enter Islamic finance.
HSBC established the Amanah Islamic Finance brand in 1998 and Deutsche Bank, Citi, UBS and Barclays quickly joined the fray, all offering interest-free products for wealthy Arabs.
However, this new generation of Islamic bankers had cut their teeth in the City and Wall Street, and were used to creating sophisticated financial products.
They often bumped heads with the Sharia scholars who authorised their products as Sharia compliant.
However, these bankers had a way of dealing with this, as one investment banker based in Dubai, working for a major Western financial organisation explains:
"We create the same type of products that we do for the conventional markets. We then phone up a Sharia scholar for a Fatwa [seal of approval, confirming the product is Shari'ah compliant].
"If he doesn't give it to us, we phone up another scholar, offer him a sum of money for his services and ask him for a Fatwa. We do this until we get Sharia compliance. Then we are free to distribute the product as Islamic."
This "Fatwa shopping", which was carried out by some institutions, brings us back to the Sharia scholars.
Even these scholars do not agree all the time, which means that in some cases a product is deemed Sharia compliant in one market and not in another.
This is especially the case with Malaysian products, which are often deemed not Sharia complaint in the more austere Gulf.
"Often no rulings exist for modern day problems, such as use of narcotics," Alamad explains.
"In Islam intoxication by wine is forbidden, but at the time of the Prophet Mohammed there was no crack cocaine."
Modern scholars had to interpret the rules on intoxication, and the consensus was that crack should also be forbidden to Muslims, as it is a dangerous intoxicant.
"This is how we make rulings, whether in finance or societal," Alamad says. "The consensus rules, which usually will become mandatory for all Muslims to follow, but there are some opinions and sometimes scholars are not in the consensus."
Banking is banking
This makes it more important to be in the consensus, and so getting a favourable ruling from a leading Sharia scholar is important for a product manager.
That is why the top scholars can earn so much money - often six-figure sums for each ruling.
The most creative scholars are the ones in the most demand, says Tarek El Diwany, analyst at London-based Islamic financial consultancy Zest Advisory.
"To date, most Islamic financiers have been looking at examples of financing in Islamic history and figuring out how to apply them to today's financial products."
But banking is banking.
It is the taking of a deposit and then using it to finance a purchase or business.
The lender pays the depositor compensation for the opportunity cost of his money, and the person borrowing the money "rents" it off the bank.
The same symbiotic relationship occurs whether it is conventional banking, ethical banking, Islamic banking or Presbyterian banking.
As Majid Dawood, chief executive of Yasaar, a UK-based Islamic finance consultancy says: "Everything that is not forbidden in the Holy Qur'an is OK.
"Yes, the industry has to evolve, but it is only 40 years old and its competing with a conventional finance system that is over 800 years old."