Two fundamental principles of modern legal theory of money are nominalism and currency. Both refer to the object passing as money, and its use in payment of debts. Under the former, this object circulates and is tendered in the value of prescribed abstract units of account, as defined by law from time to time, regardless of its own intrinsic value, or even the obligation to redeem it at something of that intrinsic value. Under the latter, this object passes from hand to hand in circulation free from adverse claims of prior owners. A third principle, existing side by side with the two enumerated above, is the issue of the object under the authority of a state and its acceptance by the public at large.