The document summarizes Keynes' reformulation of the quantity theory of money, which brought about a transition from a monetary theory of prices to a monetary theory of output. According to Keynes, an increase in the money supply indirectly affects prices through its impact on interest rates, investment, effective demand, employment and output. As long as there is slack resources (redundancy), prices remain stable despite increases in output and money supply, as productivity and effective demand rise proportionately. Only at full employment will further money supply increases directly lead to price increases in the same proportion. The document supports this with two diagrams.