[wesleyd]

My mental model of historical/religious objections to usury (which in this context refers to _any_ interest at all), is it's the lack of shared downside that they hate. Presumably because without ways to escape the debt, interest turns into slavery [0]. Investment - in which the supplier of capital participates in the downside - has pretty much always been fine?

(Taleb's "Skin in the game" talks about this a lot. _Great_ book.)

The lack of shared downside is pretty much universally objectionable - nobody likes anybody getting something for nothing - and different societies deal with it differently. Some societies just flat out banned lending for interest. Most societies today allow lending, but have get-out clauses, like bankruptcy, to prevent de facto slavery. The US has particularly generous (to the debtor) bankruptcy laws, AIUI.

Aside: Europeans are often horrified at the US's putative bankruptcy system for surprise medical bills, because they imagine bankruptcy is like it is in their country - where you lose everything, including even your home, you have basically no way of starting over, you can't be e.g. a company director for potentially years, and you carry a stigma for life, and even your kids might carry the stigma. Yes, the US's medical bankruptcy thing is pretty horrible, but bankruptcy in the US isn't anywhere _near_ as terrible as it is in e.g. Ireland. You likely won't lose your house; you're not going to starve; you can totally start over, there needn't be _any_ shame involved. Most debts will be just ... written off, some will be "restructured". It's very pragmatic, AIUI. (ICBW about all this, and I've no doubt there are horror stories, but I suspect they are very much the exception. Counterpoints welcome!)

Still, most states in the US ban "usury" - "too much" interest.

[0] Even societies that tolerated slavery didn't want it for "people like them".