Happy Birthday, Denis Healey! The former Chancellor of the Exchequer is 98 today, and one does not have to be a supporter to admire him – let alone to wish this book-devouring, evergreen and magnificently politically-incorrect figure (“now take your knickers off”) many happy returns.  Healey was the man who first applied to politicians the word that is now a cliche: “hinterland”.  He has an immense one himself, being deeply engaged with pictures, music, and poetry: his photographs have been exhibited.  Even those who don’t agree with his politics, or who will never forgive him for his part in Labour’s failures of the 1960s and 70s, will acknowledge his war service: he was Military Landing Officer to the British assault brigade for Anzio.

Healey is a survivor of an era which saw the Second World War, the Iron Curtain, the Cuban nuclear crisis, the Winter of Discontent, class politics, higher turnouts and bigger politicians.  The age in which David Cameron is Prime Minister has its own epic challenges – Islamist extremism being not the least of them – but party politics engages far fewer people and political ideology packs a less powerful punch.  A Jeremy Corbyn Labour leadership will change very little of this, if any at all – which may come as some comfort to Healey himself.  Tens of thousands who have joined Labour to vote for Corbyn will do so today before moving on tomorrow.

It is not disrespectful, therefore, to say that David Cameron’s life to date is less gripping than Healey’s: to help plan the Anzio landings was to play for higher stakes than to help plot the 1992 election; to be Defence Secretary for six years during the Cold War is a bigger thing than to have been Shadow Education Secretary for a few brief months in 2005.  One might counter that Cameron, unlike Healey, has achieved the premiership.  But no biography written now is as likely to capture as much of Cameron as Edward Pearce’s has captured Healey – because Cameron’s premiership is still a work in progress and, therefore, no biographer can have access to the equivalent of the papers available to, say, Charles Moore for his biography of Margaret Thatcher.

And as Moore has pointed out, Cameron’s official biographer, whoever he or she may eventually be (Andrew Roberts, anyone?) will find far less on paper than he has: freedom of information has seen to that.  This background helps to explain why the extracts from Anthony Seldon’s biography of Cameron, published in today’s Mail on Sunday, are so underwhelming.  We learn that Cameron once sent Boris Johnson a text with the f-word in it, that George Osborne would have been willing to swap a lower top rate of tax for higher property taxes on richer people – oh, hang on: that’s been written before – and that Andrew Lansley messed up the health bill (which has been written many times previously, too).

These are meagre pickings.  Then again, we aren’t talking Moneypenny and Buckle here – that’s to say, the monumental six volume biography of Disraeli for which the two authors scoured every scrap of paper they could find for information.  Modern political biography makes its money not so much from the book itself but from the serialisation.  This doesn’t necessarily make it worse, but it does make it different – and, if the subject is alive and the paper trail is thin, it is a challenge for the biographer to make a success of the project.  But even within the cramped scope that serialisation offers, Seldon’s extracts won’t have marmalade spoons dropping onto breakfast tables this Sunday morning.  We will soon find out if Lord Ashcroft, ConservativeHome’s proprietor, and Isabel Oakeshott can do better.