Subjected to scrutiny

Your article "A clear case of laxative enforcement policies" (28 August) listed many egregious student howlers, but the definition of nirvana as "beyond the very ideas of existing and not existing" didn't strike me as one of them - it seemed to me an elegant expression of a difficult idea.

If student answers are to be held up to ridicule in this way, examiners ought to take care that they don't expose themselves to worse ridicule by publicising their own incomprehension.

Iain Ross, Oxford.