The medical scenario may be laughable but, transferred to the context many schools and classrooms today, quite ... (in)conceivable?
This is an extract from a classic and wonderfully dangerous book titled 'Teaching As A Subversive Activity' by Neil Postman and Charles Weingartner, written in 1971 (!!!).
If you haven't read it (ever or recently) I warmly recommend it.
The presentation, like any good teaching, is meant to be a conversation starter and generator of important questions.
Expanded at http://tomazlasic.net/2011/02/inconceivable/