Although I understand the author's intention, this isn't a very good explication of the points he's trying to make.
As an example, he doesn't really seem to understand the “change” in the Church's view of usury.
Usury is still a sin. And at one time, charging interest on loans was generally usurious.
The issues of interest/usury revolve around the social and economic development of society, changing the nature of money, and the development of capitalism. In a pre-capitalist society, charging interest is almost intrinsically usurious. In a capitalist society, it isn't. Those who lived before the development of capitalism might not have even been able to imagine non-usurious charging of interest on money.