A good diarist is both like and unlike a good novelist.  He is like one, in that he is ruthless, perceptive and surprising – casting light on his subject and having an eye for detail.  He is unlike one in that he must put himself centre-stage; most novelists don’t appear in their own creations at all (unless disguised).

Enoch Powell once dismissed writing his memoirs because it would be “like a dog returning to its own vomit”.  To be a diarist, you must believe that your vomit is worth returning to.

Which brings us to Alan Duncan, whose diary serialisation in the Daily Mail closes today.  It should be said at once that serialisations are not necessarily a good basis for making a judgement about a book.  Andrew Gimson won’t have read all of it yet, but will have done by the time he writes his review for this site later this month.

On the basis of what we’ve seen so far, Duncan is certainly ruthless.  A good novelist must be prepared to kill a character, however fond of him he may have become, if it is necessary for the sake of the plot.  Duncan has duly burnt his colleagues, and perhaps his friends, in service of his art.

The extracts are also perceptive if almost wholly unkind about other people.  If they are self-deluded, so much the better.  Even in today’s extract, and its snapshots of the 2019 Conservative leadership contest, he can’t help mentioning the eternal Alan Duncan leadership bid, even if on that occasion it was to dismiss it.

It’s hard to think of a good political diarist who wasn’t obsessed with his own career prospects: if you doubt it, read Alan Clark’s, the greatest of the modern age.  (Clark also proves that a wonderful diarist isn’t necessarily a nice man: indeed, being a nice man is probably unhelpful.)

The question that remains is whether the diaries will surprise.  Clark is capable of astonishing his readers: conscious of his class status and not exactly a moralist, he can in the same item “nostalgicise for government by the upper class” and praise Ted Heath for purging toffs: “and who is to blame him? Profumo exposed their essential rottenness”.

Nothing in Duncan’s extracts seems particularly unexpected, though he is interesting about what it’s like to pursue the Palestinian cause in the Conservative Party (not always easy).  And he can laugh at himself: “at long last”, he writes of smartening up Foreign Office signs around rising bollards and underneath arches: “this will be my lasting legacy!”

Behind the joke lies a decision.  If you don’t know anything at all about Duncan, and simply looked up the bare facts, you would find a former senior Minister with a knighthood who had served in a great department of state.  These diaries suggest that this isn’t how he wants to be remembered.

He presumably isn’t top of Boris Johnson’s list for a peerage, or if he was before he probably isn’t now. So he has gone instead for being The Explosive Private Political Diaryist – to adapt the title of his book only slightly.  A striking feature of the extracts is a yearning for grown-upness.

May’s former Ministers are “the sensibles”; politics should be “a journey of duty and obligation”;  Mark Lancaster is “a superstar cool good guy”. “My mantra is simple: loyal to Theresa, loyal to Boris, stay out of the news,” he writes at one point.  It’s as though he is yearning for others to reflect back at him qualities he wants to find in himself.

Clark mentions Profumo on another occasion in his diaries, as he pads around the old War Office building.  “I tiptoed into Jack Profumo’s private bathroom, still bearing traces of Valerie Hobson’s redecoration, and telepathised for him: those moments of anguished realisation, when he must have known the Keeler affair was breaking.”

The camera then pans out, as the author reflects on the Big Push being planned during “the Great War” in that same office.  “How many hundreds of thousands of Death Warrants were stamped in these rooms?”

Clark had a touch of Keats’ famous “negative capability…when a man is capable of being in uncertainties, mysteries, doubts, without any irritable reaching after fact and reason”.  Whether Duncan can manage negative capability we will see, but he can certainly be capably negative.