SO much of the way we think about politics we owe to the ancient Greeks. Monarchy is a Greek idea. So too are its sibling rivals, aristocracy and democracy. Monarchy means rule by one. That one does not have to be hereditary. In ancient Greek terms Putin is a monarch. Any tyrant is. But our monarchy is not a tyranny and, like all remaining monarchies in Europe, it is hereditary.

On one level it’s a bonkers idea: to have as your head of state someone who comes to wield sovereign authority not on merit, still less by election, but by sheer accident of birth. And yet: is it so crazy? After all, there are thousands of small family businesses that are handed down from parent to child, just as there are farms all over the country that have been owned, managed and run by the same family for generations. Is that bonkers? Surely not.

Reflecting, as we all inevitably are this week, on the nature of monarchy, its past and its future, two thoughts struck me. First: even if it is irrational, that really does not matter very much; and second, it is no madder – no more irrational – than that other great mode of rule the Greeks bequeathed to us, democracy.

To take the first thought first: surely the lesson of this week’s extraordinary events is that politics, government, rulership, statecraft (call it what you will) is not and never has been purely a matter of the mind. It is a matter also of the heart – a question of sentiment and sensibility, of passion and emotion – as well as reason. It isn’t reasonable to mourn someone we never met – our collective, national grief is not driven by cognitive calculation. It's driven by emotion. In particular, by a sense – by a sentiment – of collective connection and loss, by a sense of what our nation is and of how it was embodied (quite literally) in the person of the Queen.

It follows, I think, that attacks on monarchy and indeed also defences of it, which focus on reason, miss their target entirely. Monarchy is not logical. But to point that out diminishes not one jot its appeal, its aura, its power or its legitimacy. For it derives these not from logic but from the heart.

Aristocracy, for the Greeks, did not mean rule by the landed elite. It meant rule by the few: in particular, by the wise. It has fallen quite out of fashion, perhaps because it is the only one of the three ancient Greek modes of rule that really does make sense, rationally.

Let’s take the arbitrariness of the one (monarchy) and the whims of the many (democracy) out, and allow only those few who are wise enough to rule. There is reason there, for sure, but no passion. If what we are learning this week is that it is the passions of politics that keep the flame alive, perhaps that is why there are no aristocracies any more. All head and no heart appeals to no one.

Democracy, of course, means rule by the many, and it is every bit as bonkers as monarchy, although for different reasons. Government is hard: it requires expertise, as well as diligence, inspiration as well as hard graft. It is not for everyone. If you needed life-saving surgery you would not walk down Sauchiehall Street asking for the most popular opinion about how it should be conducted. If you wanted to fly to New York you would not want your captain to be sitting in the cockpit only because she had been popularly elected. You’d want a well-trained expert.

But when it comes to running the country we do precisely the opposite of what we do when we need a doctor or a pilot. We ask the great mass of the ill-informed, prejudiced, easily whipped-up, all-too-often misled, unwashed, idle public. And thank God we do. It’s beautiful. It can be exhilarating. It’s core to our sense of ourselves. And it’s completely stark raving mad.

It isn’t even close to being a reasonable thing to do. It’s just, as Churchill quipped, the least worst option – all other forms of rule being even worse. We do it because we love it. Again, it’s a matter of the heart not the head.

Which brings me full circle. If the key to monarchy’s success lies not in the heads but in the hearts of its subjects, how can our new King enthrone himself as a King of Hearts?

He is himself a passionate man. Of that there can be no doubt. Just ask modern architects, or those who have crossed swords with him over his outspoken views on the environment, of which he was a champion long before we called it the climate. It is said – and indeed it has been said by me – that now he has ascended to the throne he must leave behind the campaigning, “meddling” Prince he was throughout his late mother’s long reign.

But perhaps he shouldn’t, at least not altogether. Perhaps King Charles has a way to the hearts of, in particular, his younger subjects precisely by championing the causes of which they – and he – are so passionate. The climate. Social exclusion. Alienation.

Of course the new King must adhere to the rules of modern constitutional monarchy. But perhaps that does not mean he must neuter himself. Perhaps he has known all along that it is only in the hearts of his people that he can find any of the affection and love that so many of us, whatever our other differences, had in abundance for his mother. And perhaps he knows that, in order to attract even a semblance of it for himself, he has to speak from the heart, and not hide his lifelong passions away, out of sight.