An anonymous MP who met Theresa May to discuss the EU expressed their surprise at the fact that she read from a script. To this Nick Boles replied, in a wonderful example of counter-advocacy, that:

She always does that. She did the same when I had a private meeting with her to talk about the government's housing strategy.

This highlights Ms May's failing. When you're engaged in multilateral negotiations - in which the EU is only one counterparty and perhaps not the most important - you need intellectual flexibility and interpersonal skills. Which is what Ms May doesn't have. What she does have is stubbornness which is, as Simon says, "the worst quality for a PM in the current situation."

This is not to say that stubbornness is a bad thing. Not at all. When you are on the right course and beset by doubters and nay-sayers, it is a virtue. Sadly for Ms May and the country, this is not our current situation. It's not that Ms May lacks qualities. It's just that the ones she has are the opposite of those we need. To borrow Noel Gallagher's metaphor, she's a woman with a fork in a world full of soup.

The point here goes back to Aristotle. Whether something is a virtue or vice depends upon context. In the wrong contexts, courage becomes recklessness, prudence becomes meanness, resolve becomes pig-headedness, an ability to delegate becomes laziness and so on. And in the right context, vice versa. (The skill of the obituarist consists in part in using these redescriptions.)

When you're hiring somebody for a job, therefore, what you want is not simply the best person. You want the right person - one who fits the job requirement, whose strengths are those you need, and whose weaknesses won't be shown up. Whether a hire is a success or failure will depend not merely upon their own qualities but upon the match between their own characteristics and those of their colleagues and the job requirement.

To give a few examples:

- The performance of both equity analysts and heart surgeons (pdf) varies when they change job: their success depends upon how well they fit their colleagues, not just their own qualities.

- Football managers succeed or fail depending upon how well they fit the club. Jose Mourinho is considered a failure at Man Utd, for example, in part because he was a defensive-minded coach at a team that had a culture and expectation of attacking football.

- Bosses who leave General Electric for other firms have very different results (pdf) depending on their match with the job: an engineer in a job that requires marketing skills will fail, for example.

- Winston Churchill's pig-headed belligerence made him a liability in politics for decades. But it was just what the country needed in 1940.

Very often, though, hirers and the commentariat don't sufficiently appreciate this They attribute success or failure to the individual when instead it is the product of the match between the individual and her environment: this is a version of the fundamental attribution error. This leads to what I've called cargo cult management - the idea that all will be well if only we hire the best person, whilst failing to specify the precise mechanism through which the "best person" will achieve results.

From this perspective, the opinion poll question "who will make the best PM?" is a stupid one. Nobody is perfect: everybody has weaknesses as well as strengths. What we need is not the best PM but the right one - one whose scant few strengths are those we need and whose many weaknesses need not be decisive.

Jeremy Corbyn, for example, has obvious weaknesses. He's a dodgy judge of character, lazy and not intellectual. But he has virtues too, such as a common touch which Ms May lacks. (In this sense, oddly, there might be similarities with Ronald Reagan). What we should ask is whether this bag of virtues and vices is a decent fit for what the country needs. It's not impossible that it just might be.