The Keynesian Revolution is one of the most remarkable episodes in the entire history of economic thought; certainly never before and perhaps never since has the economics profession been won over so rapidly and so massively to a new economic theory.
If liberalism's core doctrine is that, given institutional adherence to the rights of life, liberty, and property, civil society can be counted on by and large to run itself, and if the showcase example in liberalism's brief is the undirected market economy's capacity to function satisfactorily, then the "Keynesian Revolution" signaled the abandonment of liberalism.
The sum and substance of the "Keynesian Revolution" was the thesis that there can be an unemployment equilibrium on the free market. As we have seen, the only sense in which this is true was known years before Keynes: that widespread union maintenance of excessively high wage rates will cause unemployment.