I've been working on my PhD today. It's meant returning to a lot of philosophy which I haven't considered for a long time. The issue is 'value' and the role that Realistic Evaluation can play in identifying the value in interventions. One of the most interesting things is the way that opposing positions can be seen to be commensurable. This is something in the VSM, where one regulating mechanism can be seen to be commensurable with another despite them doing almost contradictory things.