Colin Parry, whose son Tim was one of two young boys killed in the IRA's Warrington bomb in 1993, is a very eloquent man, who has sought to avoid similar atrocities by opening a peace centre in the town. But even a man of such good heart cannot forgive those who murdered his child and his feelings mirror those of a large number of people who have been bereaved in Northern Ireland.
That is a legacy of the past which probably can never be erased while those who have suffered still live.
Yet in spite of his anguish, Mr Parry felt able last night to welcome former IRA leader Martin McGuinness to deliver his centre's annual lecture.
The deputy first minister, to his credit, admitted that the bombing was inexcusable and charted his own journey from masterminding conflict to working for peace. In any attempt to find reconciliation for past hurt, there has to be acceptance of the wrong done in the past and contrition for it. Mr Parry, by his invitation, opened the door to allow such dialogue. Yet Mr McGuinness, speaking before the event, also showed the difficulty inherent in a truth and reconciliation project. He attempted to create some sort of parity between the actions of the security forces during the Troubles and those of the IRA. That fudging of history is not uncommon but it can never be accepted by the majority of ordinary citizens who lived through the Troubles. Much of what he said about Warrington and his sorrow at what the IRA did there is laudable, but that does not mean that we have to accept in its totality his analysis of the causes and events during the Troubles.
While there were some questionable actions by the security forces, most people will find it repugnant to equate those with planting a bomb in a bin in a busy shopping street.
That in a nutshell is what makes dealing with the past so difficult – as Richard Haass will find out in the coming weeks.
Everyone wants to give their version of history instead of simply admitting to their own misdeeds. Warrington was inexcusable and shameful.
It should be left at that and no attempt made to equate Mr Parry's suffering with that of anyone else.