“Many everyday concepts have fuzzy boundaries, and the mind distinguishes between a fuzzy boundary and no boundary at all… ‘Adult’ and ‘child’ are fuzzy categories, which is why we could raise the drinking age to 21 or lower the voting age to 18. But that did not put us on a slippery slope in which we eventually raised the drinking age to 50 or lowered the voting age to 5.”
(quoted in Moral Clarity by Susan Neiman)
