Iran, it is true, has a proven capacity to surprise.
It has a proven capacity to absorb large numbers of migrants.
But the hospital has a proven capacity for unpleasant surprises, not all having to do with suddenly ballooning deficits.
And then there is Ms Royal; the losing candidate from 2007 may have faded from view for now, but she has a proven capacity for headline-grabbing disruption.
"Taken globally, the younger generation of the jihadist community is becoming more supportive of Isis, largely out of fealty to its slick and proven capacity for attaining rapid results through brutality".
" 'Smile, Nola, Smile!' calls on New Yorkers to remember their proven capacity for achievement, the better to prepare for the hard work, the bitter choices, the probably unequal sacrifices that lie ahead".
I doubt that this is what the banks are actually setting out to achieve for they have a proven capacity to do anything, however underhand, to increase their profits.
That we should be flexible in our views, given our proven capacity for mistakes, such as the time in 1989 that we praised Thomas Gulotta, then the Nassau County executive, for his "firm grasp of budget issues".
A country plagued by crowded prisons and turnstile justice can do much worse than invest in a program that uses the proven capacity of good literature to reform criminal offenders.
But if you have a proven capacity for, say, successfully leading teams and a job that primarily involves working on your own, then it's worth considering whether you are making the most of what you have to offer.
