Indeed, legal tender notes have become the universal measure of values. If now, by our decision, it be established that their debts and obligations can be discharged only in gold coin; if, contrary to the expectations of all parties to these contracts, legal tender notes are rendered unavailable, the government has become an instrument of the grossest injustice, and debtors are loaded with an obligation it was never intended they should assume. A large percentage is added to every debt, and such must become the demand for gold to satisfy contracts, that ruinous sacrifices, general distress, and bankruptcy, may be expected. These consequences are too obvious to admit of question. And there is no well-founded distinction to be made between the constitutional validity of an act of congress declaring treasury notes a legal tender for debts contracted after its passage, and that of an act making them a legal tender for the discharge of all debts, as well those incurred before as those made after its enactment. There may be a difference in the effects produced by the acts and in the hardship of their operation; but in both cases the fundamental question, that which tests the validity of the legislation, is, Can congress constitutionally give to treasury notes the character and qualities of money? Can such notes be constituted a legitimate circulating medium having a defined legal value? If they can, then such notes must be available to fulfil all contracts (not expressed by exception) in money, without reference to the time when the contract was made."