Are we obligated to pay old debts and charge off debts?

This is so not food related but I wanted to find out what others think. Do you think people have an obligation to pay a charged off debt?

During a conversation with one of my sons this morning he said he got his credit reports last week and there were two charge offs from almost seven years ago. They're both due to roll off soon and other than those two he has about $3,600 in non-student loan debt. Apparently he plans to tackle the two charge offs at some point down the road but not any time soon. He agrees we might have a moral obligation to pay such a debt but isn't concerned about it.

I, on the other hand, think we definitely have a moral obligation to pay debts, even old and charged off debts. So what if the company got a tax break on the bad debt - we still owe them that money and not paying it is theft.

What do you think? Do we or do we not have an obligation to pay old/charged off debts? Input greatly appreciated!