‘Away with the cant of “measures not men”! — the idle supposition that it is the harness and not the horses that draw the chariot along. No, Sir, if the comparison must be made, if the distinction must be taken, men are everything, measures comparatively nothing.’ George Canning said this in 1801 and recent events remind us that he was right.

In the end the only way to change the policy is to change the person, as the individual determines the direction and is rarely willing to try a different route. As I have known this quotation for decades, it was naïve of me to expect the Prime Minister to change her policy. It is not how it works: the wrong policy means the wrong person.

This article is an extract from Jacob Rees-Mogg's Spectator diary, which appears in this week's magazine