Final answer:
The enforceability of a promise to pay a debt past the statute of limitations varies; while the debt is not wiped clean, the legal remedy is barred. However, a new promise by the debtor may revive the debt's enforceability if it constitutes a valid contract.
Step-by-step explanation:
The enforceability of a promise to pay a debt after the statute of limitations has expired can depend on the jurisdiction and specific circumstances. Generally, a statute of limitations sets a time limit for creditors to initiate legal proceedings to collect a debt, after which the debtor's obligation is not extinguished, but the creditor's legal remedy is barred. Nevertheless, if the debtor acknowledges the debt and makes a new promise to pay, this may constitute a new agreement, which can be enforceable, provided that it meets all the criteria of a valid contract, including consideration, a meeting of the minds, capacity, and legality. This restoration of legal enforceability occurs because the debtor’s new promise can be seen as waiving the statute of limitations defense. However, legal advice should be sought in such cases, as laws can vary widely.