Science Fiction is a base class

Over at Velcro City Tourist Board, Paul says that Science fiction is a floating point variable, not a binary.

I prefer to think of Science fiction as a base class and a book is a multi-inheritance capable derived class. ;-)

Or even: IScienceFiction, IFantasy, ICyberpunk. Although not sure what the base IScienceFiction interface would have as method. ContainsSpeculation() maybe?