WHEN Hegel published his Phenomenology of Spirit in 1807, in which he first advanced the notion that the central struggle of humanity is for recognition, he probably didn’t anticipate that it would be “praised and blamed for existentialism, communism, fascism, death of God theology and historicist nihilism”, as Wikipedia snappily puts it. He would surely, however, have been horrified to discover that his big idea would find its 21st-century manifestation in reality TV, selfies and the Instagram generation.

You may be asking, as the characters in Malcolm Bradbury’s novel The History Man keep doing, “Who’s Hegel?” Which, in a world where having been on Big Brother or The Only Way is Essex qualifies you for Celebrity Strictly Come Dancing, may undermine Hegel’s thesis.

It is a peculiarity that in recognising others (what the philosophers call “normative” recognition) we also formulate opinions and judgments about them, often on remarkably flimsy grounds. That’s difficult enough in real life, but even stranger when it’s people in the public eye whom you may never meet.

The usual response to this is: “it goes with the territory”, which is rather unfair. Fame may motivate many, but some people – even actors and pop stars – dislike the limelight. The trouble is that a public image serves a purpose. Unless you’re a casting director, it doesn’t matter in the case of actors, whose job is in any case to pretend to be someone else. But it does for politicians.

No matter how much we ought, no doubt, to make our political judgments on the policies and principles politicians espouse, the reality is that we also make an assessment of their competence and trustworthiness on all sorts of other grounds. Sometimes these are downright barking. I can remember one voter declaring that she always liked Michael Heseltine because he “had beautiful hair”. But it seems reasonable to take into account, for example, the fact that Boris Johnson seems to get by on quite a lot of bluster, or that Jeremy Corbyn is congenitally incapable of admitting that he has ever been wrong. The difficulty lies in the fact that the perceived credibility and attractiveness of a politician has a considerable bearing on his or her electoral viability.

Taking three quite different leaders, it’s self-evident that the public personalities of Margaret Thatcher, Bill Clinton and Tony Blair played an enormous part in the fortunes of their respective parties. But it’s also true that each of their governments had clear priorities and direction, even if Mrs Thatcher’s was highly contentious, Mr Clinton’s stymied by a logjam in Congress, and Mr Blair’s initial popularity was replaced by an equally vehement disapproval after Iraq.

I don’t think that one can say the same about David Cameron’s administration. Mr Cameron’s chief reason for being prime minister appears to have been his belief that he was the sort of person who ought to be prime minister: in so far as the Coalition Government had a purpose, it was forced on it by circumstances and driven by George Osborne (which was to reign in public spending and try to pay off the huge debt that had been incurred).

Of course, I may be biased, because I formulated this judgment of Mr Cameron when he came to most people’s attention, which was when he made a speech almost exactly 13 years ago at Tory conference, launching his bid to lead the party. Addressing the fact that no one knew who he was or what he stood for, he said: “I believe that if you’ve got the right ideas in your head and the right passion in your heart, and if you know what this party needs to do change [sic] then you should go for it”.

Much to my surprise, this load of old flannel – exactly the kind of stuff you’d expect to get from someone who had been not only a PR man, but a PR man for, of all vacuous things, a television company – was taken seriously by lots of people, even some quite sensible ones.

But the very fact that it was, it then occurred to me, was the sole point in its favour. I might think Mr Cameron was a lot of hot air in a suit, but some people – and the crucial point, people who had not previously imagined that they might vote for the Tories – thought, on the basis of this woolly guff, that he might make a passable Prime Minister. And so it came to pass.

Which brings me to the subject of Ruth Davidson. Precisely, to the subject of what Ms Davidson is for. In one sense, the answer is the same as it once was for Mr Cameron and (as Mr Cameron put it in one of his few good lines, when telling Tony Blair: “you were the future once”) his predecessors. She is for making it not unimaginable that you might vote Conservative.

And in this respect, most people – even those who wouldn’t dream of voting Conservative – would conclude that she has been a success. But within the Conservative Party, she has fulfilled another function, which is that of not being Theresa May. As a result, Ms Davidson has frequently been regarded by quite a lot of commentators and Tories themselves as a potentially smart choice to lead the party, despite the fact that she isn’t even an MP.

Like Hegel, Ms Davidson has written a book, and to promote it she gave an interview in which she seemed to rule herself out of contention. She also revealed that she has previously had mental health difficulties, and that she wouldn’t want the job. “Who can blame her?” is the natural response to that, but it may also make some people more than ever convinced that she might be a good candidate for the post.

I think that’s an error. It would be quite wrong to take against Ms Davidson on the basis that she’s had a period of depression, that she’s a lesbian, she’s from a modest background, a member of the Church of Scotland and a supporter of Dunfermline Athletic, but by the same token, none of those things is particularly a recommendation, unless they make the public like you enough to get elected. What matters is what Ms Davidson’s policies and principles are. I would have addressed those, but I’m afraid she hasn’t given me any clues yet as to what they are.