 Why, despite the existence of seemingly obvious counter-examples, might someone be led to think that constitutional norms must be written rules, as opposed to more informal conventions or social rules? One possible  reason[10]  is that unwritten rules and conventions are sometimes less precise and therefore more open to interpretation, gradual change, and ultimately avoidance, than written ones. If this were true, then one might question whether an unwritten rule could, at least as a practical matter, serve adequately to limit government power. But there is no reason to accept this line of argument. Long standing social rules and conventions are often clear and precise, as well as more rigid and entrenched than written ones, if only because their elimination, alteration or re-interpretation typically requires widespread changes in traditional attitudes, beliefs and behaviour. And these can be very difficult to bring about.