“As an example, my father (a fundamentalist Baptist Minister) hates sleeping under a duvet, preferring a sheet and blankets. My mother prefers a duvet and so sometimes my father has to comply with her wishes. But he’s spent the past 20 years on a crusade – he asks just about every man he meets whether they like duvets. Despite any evidence to the contrary he’s utterly committed to his thesis that all men hate duvets and are only tricked into sleeping under them by their wives as part of an evil female conspiracy. This is a small and rather silly example, but it shows how he thinks – if it turns out that duvet-liking and duvet-hating are equally valid forms of experience (and even that he’s in the minority in hating them), then he feels personally threatened. So he can’t accept that those who like duvets don’t want to impose their preference on him.”