The Keynesian revolution in economic policy
Before Keynes, neo-classical marginalist economists believed that capitalism was stable if left to its own devices. These economists held that a capitalist economy tended strongly toward an equilibrium at full employment of both workers and machines. Therefore, if a recession were to occur the response of the authorities should be pretty much confined to having the central bank lower the discount rate. Otherwise, the government should stay out of the way. As long as it did, the marginalists claimed, the capitalist economy would quickly move back to its only possible equilibrium position, “full employment.”
The events that followed World War I, especially the U.S.-centered Great Depression of 1929-1941, discredited this view. Under the influence of Keynes—and more importantly the Depression itself—most of the new generation of (bourgeois) economists believed that it was now the duty of the capitalist government to actively intervene whenever recession threatened.
Bourgeois economics split in two. One branch, purely theoretical, is called “microeconomics.” Microeconomics is simply the old marginalism. The branch that emerged from the Keynesian revolution is called “macroeconomics.”
Macroeconomics tries to explain the movements of the industrial cycle. More importantly, it seeks to arm the capitalist governments and “monetary authorities” with “tools” that will keep the capitalist economy from sinking again into deep depression with the resulting mass unemployment. The new stance of the bourgeois economists was that if the capitalist governments and their monetary authorities use the “tool chest” provided them by macroeconomics correctly, they should be able to maintain “near to full employment with low inflation.”
Full employment was defined by this new generation of (bourgeois) economists not the way workers would define it—everybody who desires a job can quickly find one—but rather as a level of unemployment sufficiently high to keep the wage demands of the workers and their unions in check but low enough to prevent wide-scale unrest that could lead to working-class radicalization and eventually socialist revolution.
A Critique of Crisis Theory 
I dont understand 😦 now gold isnt in circulation and banks – we dont use it as money. So how can it affect the money supply?