I'm reminded of the origins of Islamic banking from both the Muslim and kufar angles.
Primary advocates of Islamic banking, Islamic finance, etc. are the Muslim elites of the Gulf, Egypt, Pakistan, who have access to wealth through the capitalist system. Saleh Abdullah Kamel of Saudia is a billionaire with assets in Egypt and the Gulf, and wanted to incorporate various aspects of Islam into his dealings. If I recall, he founded a purely capitalist bank in Egypt decades ago, but he wanted to incorporate Islam into financing.
Kufar became interested in "Islamic financing" because they saw that Muslims in general avoided the capitalist financing system, leaving 100s of billions of dollars of personal wealth untapped.
So who did the kufar and "Muslims" invent Islamic financing and Islamic capitalism?
By certain Usul ul Fiqh adoptions, setting the principle foundation.
One such adoption : that transactions are permissible unless text otherwise renders them impermissible.
More later :insha: