In one respect Milton Friedman is still a keynesian - not on monetary theory, but on methodology. Keynes, very much against his own intensions, decided the victory of what's called macroeconomics. And it still dominates economic theory. Milton Friedman is one of the apostols of macroeconomics. (...) His theory is based on supposed regularities between statistic magnitudes. He's convinced and to believed that he historically demonstrated that there's a simple relation between the total quantity of money and the price level. (...) Nobody knows what "total quantity of money" is. Money has so many different meanings. (...) It's now fifty years that I once said in affect, that one of the greatest misfortunes that could happen in the field of economics is if people ever seized to believe in the quantity theory of money... except that should ever come to be taken literally.

Friedrich Hayek