This paper considers what lessons there might be for our contemporary 'monetary consensus' in Keynes's and Friedman's respective policy principles. I focus first on the expectations issue. For both Keynes and Friedman, monetary policy aims at the stabilisation of expectations; and in both cases, major issues arise for knowledge and uncertainty, although each conceives this in a different manner. Next I deal with the core of monetary policy principles: while Keynes's approach is at odds with our modern strategy of inflation-targeting, Friedman would warn us that, even in this case, interest-rate manipulation might not be the appropriate approach. The analysis concludes with the issue of interest rate determination-the issue of intertemporal coordination and financial stability. Policy principles are always rooted in theoretical investigation: Keynes's approach is based upon an analysis of intertemporal coordination failures, whereas Friedman's policy schemes require that financial markets be made perfectly competitive.
