The subprime crisis is Alan Greenspan's fault, or so we are increasingly told: he offered bankers too much monetary candy and should have put them on a monetary diet instead. Is this criticism justified? And what does it imply for the future behaviour of central banks?

Few now have as much confidence in the self-restraint of the financial children as Mr Greenspan was wont to. No less certainly, Mr Greenspan's reputation is sinking. Once hailed as a maestro, he is condemned by many as profligate. The truth is more complex. He was never the genius he was held to be. Nor is he the dunce some now allege. He was merely fallible. As such, he made good and bad calls.