Consider the example of whether a big terror attack indicates that there has been an increase in the average rate or harm of terror attacks. You could easily say “You can’t possibly claim that big terror attack yesterday is no evidence; and if it is evidence it is surely in the direction of the ave rate/harm having increased.” Technically correct, but then every other day without such a big attack is also evidence for a slow decrease in the rate/harm of attacks. Even if the rate/harm didn’t change, every once in a while you should expect a big attack. This in the sense in which I’d say that finding one more big tool isn’t much evidence that big tools will matter more in the future. Sure the day when you find such a tool is itself weak evidence in that direction. But the whole recent history of that day and all the days before it may be an evidential wash.
Consider the example of whether a big terror attack indicates that there has been an increase in the average rate or harm of terror attacks. You could easily say “You can’t possibly claim that big terror attack yesterday is no evidence; and if it is evidence it is surely in the direction of the ave rate/harm having increased.” Technically correct, but then every other day without such a big attack is also evidence for a slow decrease in the rate/harm of attacks. Even if the rate/harm didn’t change, every once in a while you should expect a big attack. This in the sense in which I’d say that finding one more big tool isn’t much evidence that big tools will matter more in the future. Sure the day when you find such a tool is itself weak evidence in that direction. But the whole recent history of that day and all the days before it may be an evidential wash.