By Norman Smith
BBC political correspondent
The economist John Maynard Keynes is now hailed as an economic genius, but if he were alive today, would it be his theories or his flamboyant personal life that made the headlines?
Would we tolerate Lord Nelson's unconventional personal life today?
Looking back at Britain's political leaders, it appears we have become more censorious and intolerant of public figures who stray from a conventional private life.
Alfred the Great, for example, only became great because he was too randy for the priesthood.
The Duke of Wellington enjoyed a string of affairs, Lord Palmerston is rumoured to have died of a heart attack while having sex with a young parlour maid on his billiard table and Lloyd George was known for good reason as "the Old Goat".
And yet their private lives did not seem to mater.
The same was the case for economist John Maynard Keynes according to historian Dominic Sandbrook.
"He would have led what by the standards of the time was regarded as a very flamboyant, louche, dissolute private life," he says.
"In those days homosexuality was effectively illegal, so Keynes was braking the law. But what made Keynes slightly heretical in the 1920s and 1930s was his economic ideas, it wasn't his personal life."
So what has changed? Michael Portillo, who as a Conservative MP saw his bid to be come party leader in part scuppered by the persistent whispering over his private life, blames journalists for the decline in personal privacy.
"The media intrudes where it didn't intrude before," he says.
"In the old days it was possible for there to be secrets which were known by a very large number of people."
Admiral Lord Nelson, says Mr Portillo, lived in a ménage a trios with Emma Hamilton and her husband Sir William Hamilton. Emma and Lord Nelson had an illegitimate child between them.
Keynes' economic views caused more of a stir than his personal life
"If The Sun had been onto this he would not have been allowed to command at the battle of Trafalgar," he says.
Across the Atlantic the story is much the same.
Compare US president Bill Clinton's treatment over his affair with Monica Lewinsky with that of John F Kennedy - whose numerous affairs, including with Marilyn Monroe, were kept a tight secret.
The reason for the change again falls to the media, according to JFK biographer Allan Lichtman.
"Back in the days of JFK and FDR, a very small group of reporters had access to the white house, and they did not want to risk losing their access by digging up seedy details of presidents private lives," he says.
But attitudes too have changed - our celebrity culture has created a seemingly insatiable appetite for the personal and private - and that extends to knowing about our politicians' private lives.
"The thing about celebrity culture is that anything is fair game," says Dominic Sandbrook.
You can see the change in the biographies written about notable statesmen, he says, where 50 years ago their private lives were glossed over as uninteresting to the reader.
Bill Clinton would have been treated very differently 50 years earlier
Now an enormous amount of attention is paid to the inner life and sex lives of the subject.
"That is what we seem to have an appetite for as a society," he says.
But why does any of this matter to anyone? After all, no one is forced to become a politician.
And yet the danger, according to Michael Portillo, is that it does deter people of talent from even going into politics.
"I have no doubt at all that people are deterred from going into public life," he says.
"People at university now experiment habitually, they experiment sexually, they experiment with substances.
"Even though that is acceptable in the community they live at the time, they know that 20 or 30 years down the road these things will come to light. I'm sure that people are deterred."
The trouble is that now the door into politician's private lives has been opened it is probably impossible to close it again.