Peter Evans-Greenwood makes some interesting points in response to my post on Three Wishes, but I don't agree with his interpretation of fairy tale logic as incomplete and inconsistent. As I see it, fairy tales follow a rigorous logic that produces an inevitable outcome. (From Freud to Lacan and Matte Blanco, psychoanalysts have explored the strange but inevitable logic of dreams and the unconscious.)
It is this logic that makes fairy tales so powerful, not merely as entertainment but as rich sources of metaphor. See Magic Fairy Tales as Source for Interface Metaphors
Magic follows strict rules. J.K. Rowling put a great deal of effort into creating an internally consistent magical world for Harry Potter and his friends to inhabit; although some minor logical anomalies do appear, these are trivial compared to the main elements of magic upon which the plot relies. And within the context of the Rapunzel story, climbing hair is consistent and makes perfect sense.
Now here's the relevance of this for consultants working with organizations. When we look at families or organizations from the outside we may say "that behaviour doesn't make sense", but for the people inside the family or organization the behaviour seems perfectly logical or inevitable or both.
In order to intervene usefully into such situations, the therapist or consultant needs to be in touch both with the external logic (this doesn't make sense) and with the internal logic (this is inevitable, this is how we do things).
(I read somewhere that in post-war Britain, American management consultants had some advantage over British management consultants. At that time, one of the biggest perceived issues was something called "Industrial Relations" - in other words, conflict and distrust between management and labour. Whereas British consultants were constrained by their perceived background, American consultants were outside the British class system, could pretend to know nothing about the role of the trade union in British politics, and could ask dumb but necessary questions.)
Dysfunctional organizations may sometimes be logically incomplete or inconsistent. But more often they are obsessively complete and consistent. (J.K. Rowling paints a disturbingly plausible satire of government in the Ministry of Magic - see Harry Potter and the Half-Crazed Bureaucracy). We can learn a lot from the structure of magic.