I have a ten-dollar bill.
You may have the ten-dollar bill right now.
Or, you may have it one year from now.
Do you choose to take the $10 now, or in one year?
Is there some additional sum I can offer to give you that will induce you to take the $10 a year from now? E.g., an additional dollar?
This is the one and only reason there is interest.
All the stuff about “productive loans” and “non-productive loans” is irrelevant. So is anything to do with the Reformation, or Catholicism, or the Bible, or gold, or silver, or feudalism, or capitalism, or class struggle, or Jews.
Yes, that is the motivation for the lender. We are not discussing whether the lender is motivated by usury, -- often he is, -- but the morality of it. Then the distinctions explained in the article become very relevant, and indeed this is universal morality common to all serious religions.