To the Ancient Greeks, hubris was an act of arrogance and presumption that offended the gods. For Lord Owen, leader of the ill-fated SDP in the 1980s, and himself accused of overweening pride during those turbulent times, it is a medical disorder that can turn prime ministers and presidents into despots.
In a paper for the medical journal Brain, the former doctor, who trained in psychiatry, writes that what he terms hubris syndrome is an occupational hazard for those in power. David Lloyd George had it, he concludes reluctantly of a Welsh hero, and so did Neville Chamberlain. In recent times, Margaret Thatcher and Tony Blair had it, and so did Blair's joint perpetrator of the Iraq war, George Bush.
The syndrome is not limited to politicians: Owen sees hubris syndrome in the bankers whose pride has landed them in the hands of Nemesis, the Greek god of revenge, as the public bays for their bonuses.
Owen, who previously explored political hubris in a book, hopes with his scientific paper and a discussion at the conference of the Royal College of Psychiatrists in June to persuade doctors to take hubris syndrome seriously. Acceptance by doctors will lead to greater recognition among voters and, he hopes, greater checks on prime ministers.
"Because a political leader intoxicated by power can have devastating effects on many people, there is a particular need to create a climate of opinion that political leaders should be held more accountable for their actions," writes Owen in his joint paper with Jonathan Davidson, a psychiatrist at Duke University Medical Centre, North Carolina.
Owen says hubris syndrome is a medical condition. "I have seen the isolation - this extraordinary pressure under which leaders in business or in politics live, with shortages of sleep - a generally very high-pressured existence. I'd liken it to ... a long-distance runner. You go through a pain threshold and something changes."
One day, he says, scientists may prove a shift in brain chemistry.
"The public are way ahead. The man in the street starts to say the prime minister has 'lost it'. They put it all down to adrenaline. They see these people as supercharged."
He recalls a US official's comment about Blair - "he's sprinkled too much adrenaline on his cornflakes". He realised Blair had crossed the threshold when his daughter pointed to the TV and said: "Look, he's acting, he's acting!" It happened after Blair's 2001 victory, Owen believes, with the 9/11 attacks, "although there were just the beginnings of it over Kosovo".
Margaret Thatcher got it quite late on, he says, after her 1987 victory. Her declamation, "Rejoice, rejoice", after the retaking of South Georgia in 1982 sounded hubristic but was relief, says Owen. After HMS Sheffield was sunk, she had been shattered.
On Gordon Brown, he says, the jury is still out. Brown is not Blair; he has internal struggles. "By and large introverted people don't develop it. Blair is much more overt - look at the language he used after 9/11 and the extraordinary way Bush and Blair would swagger in."
Owen acknowledges his own tendencies. "I have hubristic traits ... my wife has been a constraint on me." A loving constraint - spouse, children or friends - is one of the principal reasons that hubristic tendencies remain just that. "One of the factors that led to Margaret Thatcher developing full-blown hubris syndrome was the absence of Willie Whitelaw from the cabinet. There's also evidence that Denis [Thatcher] was a constraining factor."
Some leaders who seemed hubristic had other disorders, Owen says. US presidents Theodore Roosevelt and Lyndon Johnson had bipolar disorder, John F Kennedy was on drugs for Addison's disease and Richard Nixon abused alcohol. In Britain, Winston Churchill had depression, Herbert Asquith drank and Anthony Eden took amphetamines.
Doctors, says Owen, must not cover up for leaders. "Politicians lie about their health. Their personal doctors lie about the health of the politicians."
There's no drug treatment, but cabinet government should block messianic tendencies. Unfortunately, he says, "we haven't had cabinet government now since 1997" apart from an interlude when Brown first took over. Democracy is the best treatment, says Owen. The four prime ministers he says had hubris syndrome were brought down by backbench pressure.
Symptoms
A narcissistic propensity to see one's world primarily as an arena in which to exercise power and seek glory
A disproportionate concern with image and presentation
A messianic manner
Excessive confidence in own judgment and contempt for advice
Exaggerated self-belief, bordering on omnipotence
A belief that one is accountable solely to history or god
Loss of contact with reality; often associated with progressive isolation