Tears, especially male ones, are becoming a frequent sight on British television. In the past week alone, several of the ambitious, thrusting men competing to be Alan Sugar's apprentice on BBC2 cracked under the stress and started welling up. Meanwhile, minor celebrities, worn down by the strain of singing pop duets for Just the Two of Us, similarly shooed away the camera, lest it discover them weeping.Yet the men on another BBC programme remained steadfastly free of tears. In Facing the Truth, victims and perpetrators of violence in Northern Ireland met each other under the gentle gaze of Archbishop Desmond Tutu. They told and heard stories to break the heart, and sometimes their eyes grew moist, but these men did not cry.These remarkable films, shown over three successive nights, prompted a whole range of thoughts. First, they were a reminder of the sheer strangeness of the Troubles. Citizens of this country recalled their campaigns to kill each other; how they saw themselves and their targets as "soldiers", how they studied files, drawn up by self-styled "intelligence officers", telling them how to track down and murder their quarry. How they did this while pretending to live ordinary lives. Michael Stone, notorious for his 1988 killing spree at Milltown cemetery, used to rub dirt and sand into his clothes so that his wife would think he was a builder. One of his targets drove a Mother's Pride delivery van. Few described it this way at the time, but these programmes left little doubt: on the streets of the United Kingdom, there was a civil war.Facing the Truth prompted a question: why has Northern Ireland not had its own truth and reconciliation commission, analogous to the one Archbishop Tutu chaired in South Africa? Why had it been left to television, to the BBC, to organise one? Watching, it became clear the province needs such a process: there is no shortage of pain or people yearning to bear witness.But the programmes asked a larger question. For what was noticeable in several of the filmed encounters was a subtle, unstated pressure - not on the culprits to show contrition, but on the victims. Those who had lost limbs or loved ones were under pressure - to forgive.Carefully and sensitively, the grieving relatives were led to a climax: how would they close the meeting? Would they be able to reach out and shake the hand of those who had wrought such havoc? There was something uncomfortable about this, for it is part of a larger pressure, not confined to this TV series, which demands that those who have suffered most must also be the most generous.Which is why I feel for the Rev Julie Nicholson, the vicar who has quit her Bristol pulpit because she can no longer preach forgiveness - not after her daughter, Jenny, was killed in the July 7 bombings last year. As a Christian, Nicholson clearly felt under enormous pressure to say she could forgive Mohammed Sidique Khan, who had blown up himself and six others at Edgware Road station. But she could not do it.And now I wonder why we ask such a thing of those who have been bereaved so cruelly. Of course, there are people who are able, somehow, to meet this challenge. The mother of Anthony Walker, the Liverpool teenager murdered by racist thugs wielding an ice axe, somehow emerged from the trial of her son's killers to declare: "I have got to forgive them. I still forgive them." Last year the mother of Abigail Witchells, stabbed in front of her toddler child, spoke of her "enormous sadness" on hearing of the suicide of her daughter's presumed attacker. She said his death was the "real tragedy of the story" - and that she had forgiven him.I confess to being both in awe of and baffled by the compassion of such people. Of course, none of us can know how we would respond to so desperate a plight, but I struggle to understand how you could forgive the killer, or attempted killer, of your own child. I do not know how it would be possible to hold anything in your heart but rage and pain.There are philosophical objections one could muster too. Surely the only person who can forgive a crime is its direct victim: Anthony Walker has the authority to forgive his killers - but he is not here. For believers, I have sympathy with those who say that if forgiveness is in the hands of anybody it is, like judgment, in the hands of God alone.But these are not the prevailing or even popular assumptions. Instead, we exalt those who can forgive and regard those who cannot as guilty of a kind of moral weakness. We demand that those who have been brought low reach highest.There might be a way through this - and it would begin with an attempt to define our terms. Forgiveness has entered casual parlance as a psychological term, shorthand for "moving on", for no longer holding a grudge, even for feelings of equanimity or empathy towards the person who hurt you."If it is that, it can't be done," says Giles Fraser, vicar of Putney and author of Christianity and Violence. He dismisses the idea of "loving" the man who has harmed you or your family as "morally perverse, even if I understood what it meant. How could feelings of anger and loss coexist with that love?" That definition of forgiveness, the one we seem to demand from those who have suffered most, is little more than "cheap Christian rhetoric".No, forgiveness should be a much more realistic, pragmatic business. In Fraser's eyes, to forgive someone is merely to vow that you will not respond to their crime in kind. If they have killed, you will not kill back: you will choose instead to end the cycle of violence. On this definition, forgiveness is the literal opposite of revenge.This is a move that is much easier to imagine. Sylvia Hackett, whose husband Dermot was murdered by loyalist paramilitaries, has clearly moved beyond wanting to do to Michael Stone what he and his comrades did to her. But on Monday night's programme she seemed to feel that was not enough; she forced herself to walk over to Stone and shake his hand. When he placed a second hand on hers, she recoiled and fled from the room. It was too much. She may not have wanted to kill Stone, but nor did she want to be his friend. Yet our present day notions of forgiveness confuse the two.Not that the eschewing of revenge should be considered something small: it is not forgiveness lite. In most circumstances, we can give up our right to seek direct vengeance in favour of justice: we may not kill the killers, but at least we will see them behind bars. But in some places - Northern Ireland and South Africa among them - there is not even that comfort. Justice has been sacrificed in the pursuit of peace. That is why Michael Stone, originally sentenced to 684 years in jail, is now a free man, released under the Good Friday agreement.So we should alter what we mean by forgiveness. It is not a syrupy inscription in a greetings card; it is a painful, practical step taken by those who want to end the killing. It is not some impossible ideal: it is, properly defined, achievable - and no less admirable for that.