Stumbling and Mumbling here makes an interesting point to which I've responded on his post. But one issue he doesn't reflect upon is cluster theory- why is it that at particular points in time say in Florence in the 14th Century you get amazing amounts of creativity whereas at other periods of time you don't. One economic explanation has been to argue that bringing clusters of people together so that they can discuss things with others with similar interests means that people become more creative. There is some truth in this. However there have been attempts to create clusters which haven't worked which indicates that there are variables in this, like the morale of the workforce (something that important work is being done in Cambridge upon)- so the search is still on for what exactly it is that provokes creativity.