Or, as a representative of the Federal Reserve (one Ben Bernanke) pithily expressed it on the occasion of Friedman's 90th birthday in 2002:Regarding the Great Depression. You're right, we did it. We're very sorry.
So much for the theory of it being a result of the "fundamental contradictions of capitalism". The Great Depression wasn't caused by an uncontrolled economy. It was caused by the one-two punch of slamming down protectionist tariffs, and by trying to use the central bank to "plan" and "control" the economy. Which is very foreboding, given the recent election of a lot of pols in the US who are all for protectionist-ism and economic planning. "It failed miserably before, let's TRY IT AGAIN!"
Goodbye, Professor Friedman. You will be missed.