Many wars ago, when the only war was a seemingly endless cold one, I worked in Military Intelligence. I’ll leave you, the reader, to fill in your own joke concerning any inherent paradox. Writing any report was like trying to identify the picture of a jigsaw puzzle with missing pieces. If I – say - had a puzzle of the Mona Lisa and I was missing the 3 or 4 pieces to make her smile, I would say that it was ‘highly probable’ that the puzzle showed the Mona Lisa. If I found the missing pieces under the table and they showed La Giaconda to have a moustache and a beard, I would say that ‘Further analysis’ reveals the puzzle to show a work by Marcel Duchamp.
Wars became hotter. I continued to write mealy-mouthed words like possible or probable. My prose was littered with may, might and could. Must be and will never appeared. Others chose a different path.
Imagine you are the leader of an armed team of Metropolitan Police Officers. ‘Intelligence’ says that there is a highly probable threat of a second terrorist incident after a failed attempt the previous day. You and your team follow a dark-skinned young man with a rucksack into one of London’s smaller tube stations. The young man looks over his shoulders and leaps the barrier. Your team does the same safe in the knowledge that they are upholders of the law and must be in the right, come what may. The man seems nervous; looking behind him and checking his watch. The team follow him onto the train.
Perhaps you believe he has noticed you and your fellow policemen. He seems unable to sit still. Suddenly he removes his rucksack and begins scrabbling to open it. You note his wild eyes. Do you fire?
Of course you do. It is highly probable the man is a terrorist.
Further analysis of the man’s possessions reveal a Brazilian passport, a wallet with no money and an expired oyster card. There is also a classified ad torn from a newspaper, offering the prospect of work at an address near to the stop that the young man never quite reached.
What is the problem? It was highly probable that the man was a terrorist.
The problem is that he wasn’t.