It’s so frustrating sometime to see those so-called Keynesians (i.e. neoclassical rendering) talking about shifting equilibrium via mathematical toys like IS-LM and such when Keynes the man himself in his mature years basically was against any idea of real equilibrium in the economy.
It’s sad that most of economics students don’t read Keynes in his own words, from The General Theory to Essays on Persuasions/Biographies to really have a feeling of what Keynes really think. They just rely on neoclassical geeks like Samuelson and his gang that basically wrote the tradition of American economics text-books. That is why Keynes said “I’m not Keynesians”