[Guille]

Sub,

I don't know exactly what was in dave's mind but I can assure there is a relationship to Russell's paradox, for anyone with a minimal knwoledge in set theory, at least.

The example set of dave is a set that contains all other of it's kind (in set theory this is called a class) and thus contains itself. The thing is that the set contains all the other sets in it's class that do or do not contain themselves. Therefore, weather or not it contains itself, depends on weather or not any of it's members contain the whole class including them selves. And this is itself,so yes, it does contain itself. But in contradiction, by containing itself it would be a member contained in the class and there would need a set that contains the class including the set that contains itself in that it contains the class. Therefore this one wouldnt' contain itself, it would contain the class, but not itself. And vice versa... It is a strange version of russell's: it jsut introduces the idea of a class and the set that is the class and contains itself but not the class and the set that is not the class and contains itself but not the class and the set that is the class and contains the class but not itself and the set that is not the class and contains the class but not itself. The four of them make a double russell paradox.

Anyway, there actually is a solution to russell's paradox. I read it once in a paper in a university library. Quite complex. Mathematicians introduced the idea of "type"... I don't liek this all logical objects, they are unlogical.