With no notes — the eloquence, clarity, and conviction all his own — Rory Stewart tests a revolutionary proposition: that it is possible to become a national leader by being deeply committed to truthfulness; by being able to discriminate between reality and fantasy; and by placing national interest above personal ambition.

In a world where clowns succeed, lies flow in all directions, and the media is perpetually focused on maximizing audience size, Stewart’s seriousness is utterly out of place.

But maybe — and the chances are certainly very small — just maybe, if those Conservatives who are currently willing through an exercise in blind faith to install Boris Johnson in Number 10, Downing Street, were instead to exercise some of the prudence that Stewart commends, they would recognize that honesty in leadership is not optional but, on the contrary, it is indispensable.