The canon changes, as it must, with time. (To use one of your examples, 'The Art of War' didn't have an english translation until the early 20th century). The

The canon changes, as it must, with time. (To use one of your examples, 'The Art of War' didn't have an english translation until the early 20th century). There's also a class issue involved, see for example Dorothy Sayer's "Busman's Honeymoon" and in particular the references Lord Peter and the local throw at each other.