Two key grafs: Debt--who owes what to whom, or to what, and how that debt gets paid--is a subject much larger than money. It has to do with our basic sense of

Two key grafs: Debt--who owes what to whom, or to what, and how that debt gets paid--is a subject much larger than money. It has to do with our basic sense of fairness, a sense that is embedded in all of our exchanges with our fellow human beings. We are social creatures who must interact for mutual benefit, and--the negative version--who harbor grudges when we feel we’ve been treated unfairly. Without a sense of fairness and also a level of trust, without a system of reciprocal altruism and tit-for-tat--one good turn deserves another, and so does one bad turn--no one would ever lend anything, as there would be no expectation of being paid back. And people would lie, cheat and steal with abandon, as there would be no punishments for such behavior.