But for those in the business of assessing terror suspects the cost of a bad choice could be monumental; and those costs are usually paid by people who have no part in judging who is to be trusted and who is not.
NEVER judge a book by its cover is a pretty good rubric, especially if you live on a desert island with a dozen washed-up volumes — you’ve got the time to leaf through each one and decide on its merits.
But whether we’re talking books or people, in real life we need to make quick judgments, and anyway, we can afford the odd mistake.
Last summer, three little girls paid a price for someone else’s failure to discriminate between the merely dotty and the truly dangerous.
The attempt to lay blame at the door of online suppliers of knives is a distraction; every kitchen in Britain could have supplied the murder weapons.
