Why is this man so hated?
What is it about Neil Lennon that incites people to acts that effectively amount to terrorism?
Even in casual conversation, one hears extraordinarily polarised opinions about him, like this, yesterday, from one of Lennon's Northern Irish compatriots: "Sure, he's a cheeky b*****d -- the kind of kid you'd slap in the playground."
Lennon, though, is not the target of metaphorical smacks, but of real and vicious assaults in the street, packets of live bullets (another bullet arrived at Celtic Park yesterday, addressed to the manager) and, most recently, a nail bomb, which would have found its way to him via the mail had it not been for the vigilance of others along its route.
And let us not forget the death threats expressed through graffiti at his family home, anonymous telephone calls and truly disgusting website images. Now we have come to the stage where any fan of an opposing club, at any ground at any time, has to be considered a potential assailant.
That's the way the American Secret Service operates around the US president and it is astounding to think that it is what will have to happen with Lennon if the unfathomable rage against him continues unabated. Too far-fetched?
Well, Hearts -- or whoever was in charge of security at Tynecastle -- must have thought so, otherwise there would have been some semblance of a protective cordon around the Celtic manager.
Meanwhile, it was put to me on breakfast radio yesterday morning that "many people would say he (Lennon) brings it on himself?" I don't doubt for a moment that many people do, partly because the Celtic manager has engaged in some very public confrontations this season.
One has only to think back to Tynecastle in November, when Celtic lost 2-0 and Lennon treated the fourth official and the referee to a barrage of abuse so vitriolic that he was not only sent to the stand but charged with excessive misconduct.
Then there was the angry square-up to Ally McCoist in full view of the TV cameras at the end of the Scottish Cup replay with Rangers at Parkhead on March 2, for which Lennon subsequently apologised, saying that he had fallen below the standards expected of a Celtic manager.
And, days after it was revealed that an explosive package had been intercepted en route to him, and 1,000 extra police deployed on the streets of Glasgow, he could not resist cupping his ears in a sarcastic gesture of defiance of the Rangers fans who were vociferously taunting him at full-time.
Taken together, there is the basis of an indictment against him for incendiary behaviour -- and not necessarily of the heedless sort.
After all, it was Lennon himself who said -- echoed in comments by his assistant Johan Mjallby -- that he "knew what he was doing" at times when others concluded that he had let temper get the better of reason.
Furthermore, Lennon made it clear when he took over from Tony Mowbray that he thought his predecessor had been far too docile in his pitchside manner.
So, if there is a calculating element to some of his antics, the Parkhead manager has to accept that there will be consequences, including condemnation.
As one former Celtic manager remarked recently: "He still has to understand that everything he does is scrutinised and can and will be used against him."
Yet, at what point does Lennon's behaviour diverge from the common run of competitive frustration or even the familiar combative and manipulative actions of managers at the very pinnacle of the game -- think of Jose Mourinho and Alex Ferguson? Frankly, it doesn't.
Were Lennon in charge at, say, Crewe Alexandra or Leicester City, two of the clubs for whom he played before he made the fateful decision to follow Martin O'Neill to Celtic, there would likely be a certain critique of his style -- it might even be thought of as admirably committed, if sometimes a tad excessive -- but nothing like the cyclone of antagonism it generates when witnessed in Scotland.
Lennon recently ventured the opinion that the relentless torrent of opprobrium directed his way was purely and simply because he is an Irish Catholic in charge of Celtic.
The contrast that immediately sprang to mind was with O'Neill, whose credentials were identical but who was on the receiving end of nothing more harmful in his private life than the occasional barbed comment from Rangers fans.
Yet the two men are perceived in fundamentally varying ways: O'Neill the technically fluent midfielder in Brian Clough's elegant Nottingham Forest side; Lennon the gladiatorial, sometimes snarling ball-winner for O'Neill at Celtic.
There is a more fundamental difference -- almost primordial -- between the pair. O'Neill is urbane, ironic and subtle. Lennon is vividly expressive and rough hewn.
In fact, Lennon's face bears a startling resemblance to that of Vincent Van Gogh in the artist's late self-portraits. It is a visual paradox that Lennon should bear such a likeness to the son of a Dutch Protestant pastor that they could easily pass as brothers.
Yet he hasn't actually won anything yet. What in God's name can we expect if he manages to establish Celtic as the dominant force in Scottish football?
We cannot retreat from the possibility that the ambition that animates Lennon most could unleash a reaction too dangerous for him and his family to contemplate.
What manager could take that risk? (© Daily Telegraph, London)