What did Keynes say?

Caplan wants to apply the Krugman Turing test.
Keynes proclaimed that the private markets overcompensate for shocks, and that government is a bit more stable. Or, alternatively, government can be made more stable than private markets.

Government, in our case, has been running up the debt since 1980, yet ten year yields have steadily dropped. Our legislature seems to be learning another lesson, the more government borrows the less stimulus it gets.

Where did Keynes make his error? He used a math that the economy doesn't. Keynes assumed that markets were infinitely divisible and support intermediate solutions. I don't have to go far to find out Keynes was a dunce. I have looked at the street outside my house for ten years, it is still the same width, and the cars upon it still take one whole lane. No infinitely divisible autos around here.

Which brings up to the Krugman anti-Keynes diagnosis, Stranded in Suburbia, in which Krugmen points out exactly the problem, we do not have intermediate solutions without new technology.