In what instances would you say probability is not a high enough standard? An obvious example I think of is a murder trial where sentencing an accused to death, or life without parole based on probability isn't a high enough test. That said, I don't doubt it happens.. What if ground crew of an airline said the jet on which your child will be flying "probably" has enough fuel to make it from LA to Tokyo? Would you allow your child to board the plane? What are some other examples?