The debt of a company is the amount of money it owes either to banks, or to bond holders, or to note holders, or commercial paper holders; these are fixed incomes.

公司的债务是指一笔借来的钱,不管债权人是银行还是股东,或债券所有人,或者商业票据所有人,这些都是固定收益

耶鲁公开课 - 金融市场课程节选

That's how paper money got started, as bearer notes, because if you had gold with the goldsmith you could spend the note, at least within the town that you live in where the goldsmith was known and had a reputation.

纸币就以不记名票据的形式出现了,如果你的金子存在金匠那里,你可以直接支出这些票据,至少在你所居住的城镇可以这样做,因为金匠在本地有着并众所周知的信誉

耶鲁公开课 - 金融市场课程节选