A society exists because people are so made that they want to return to each other, are so made they like what they see.
We draw two conclusions.
First, society is based on everyone doing what they want: to return, go back to each other.
Second, on the principle of expressing what we can't see in the words of what we can see, we say that everyone "owes a debt" to oneself to make a similar return to oneself.
This raises the question why or how anyone could leave oneself, and have a need to make a return.
The answer is something happens in society that leads people to return only to some people rather than all. Some kinds of people are respected, returned to, are considered possible friends, others not. And then sometimes we allow ourselves to respect and return to ourselves, sometimes not.
The threat of violence, and consequent fear, enters into everyday social life, then enters also into how individuals think about themselves, enters into what they owe themselves. They begin to think they owe themselves safety where before they thought they owed themselves love. Owing oneself safety demands doing things that make loving and understanding impossible. Safety demands love be replaced by threats, understanding replaced by repetition of words.
Every meeting between two people begins with the possibility of love and understanding, which either is realized or diverted to violence and words without meaning.
We look back on the beginnings of society to remind ourselves what we owe ourselves to return to, what is our debt to ourselves. The language of debt then originates in this social problem of forgetting ourselves.
We are each other's creditors and debtors, both at the same time.
As creditors, we make a demand of every stranger: remind me what I owe to myself! As debtors, paying our debt is simply to remember who we are.
What is debt? We owe ourselves love and understanding, we owe others love and understanding.