but if the money of account … stands side by side (in some fixed ratio)with a commodity money (such as gold bars), then not only are there the undue perturbances of the exchange process from international movements of capital and from financial crises and crashes, but the whole economy comes to be regulated, not by the social good, not by the exigencies of the economy itself, but by the money invented to serve the objective process and the social good. [CWL 21, 104-105]

The laws of the economic process are prior to and determine the laws of the issuance and use of money. Once again,

… when we say that the idea of money as a system of public bookkeeping has to be worked out and applied, we mean above all the necessity of a money whose laws (of issuance from the Redistributive Function and of circular flows within the two real circuits connected by crossovers) coincide with the laws of the economic process, so that instead of conflict between real possibility (productive possibility) and financial possibility (ruled once upon a time by a fickle quantity of gold and a fixed exchange rate for a certain quantity of gold) we shall have harmony, and instead of bookkeepers (of the fixed gold-to-money ratio) exercising a dominant role they will fill a duly subordinate position. [CWL 21, 105]

The economic process has differences and correlations ruling the existence and use of money.

These differences and correlations (in the productive process) have now to be projected into their monetary correlates to set up classes of payments. [CWL 15, 39]