In my view, this is a situation where technology changed our understanding of morality.
When Aquinas was alive, there was nothing remotely similar to modern banking. Money was lent at punitive rates of interest (20% or more/year), with very little regulation concerning what rights creditors had if debtors couldn't pay. As an example, look at mortgages today; in many states, these are non-recourse, meaning the law limits the borrower's liability to the mortgaged property (the house), and nothing more. People aren't sold into slavery, there are no debtors prisons, and we have a sophisticated system of personal bankruptcy that lets people start over.
In short, if you can't pay a loan, you aren't getting your kneecaps broken or getting sold into slavery. In my view, that's a game-changer.
This doesn't change the fact that lending with interest is inherently evil and parasitic, even in modern times. It is completely prohibited in Islam, and Jews don't lend each other with interest.
When Aquinas was alive, there was nothing remotely similar to modern banking. Money was lent at punitive rates of interest (20% or more/year), with very little regulation concerning what rights creditors had if debtors couldn't pay. As an example, look at mortgages today; in many states, these are non-recourse, meaning the law limits the borrower's liability to the mortgaged property (the house), and nothing more. People aren't sold into slavery, there are no debtors prisons, and we have a sophisticated system of personal bankruptcy that lets people start over.
In short, if you can't pay a loan, you aren't getting your kneecaps broken or getting sold into slavery. In my view, that's a game-changer.