David Cameron's apology for Bloody Sunday has struck a deep nerve in Northern Ireland.
Nationalists embraced it, even cheered him in their thousands as they listened to his speech.
The heartfelt nature of the apology, the fact that it came after an exhaustive investigation and Cameron's straightforward declaration that the British Army had done grievous wrong made the apology utterly acceptable.
Contrast it with the Pope Benedict's apology for the rampant child child sex abuse carried out by many Irish priests which he also delivered to the Irish people.
The response was lukewarm to say the least. Unlike Cameron who showed with both words and deed that he was serious, Pope Benedict was clearly attempting a damage limitation exercise rather than directly confronting the massive problem his church had created.
The Irish public saw through that and opinion polls revealed them as very skeptical of the pope's words.
The difference is that most Irish firmly believe that the church is still hiding much of the abuse and are refusing to hold any further inquiries.
The British government on the other hand spent $300 million on an exhaustive investigation and spent 12 years documenting every possible aspect of what happened on Bloody Sunday.
So apologies have to be accompanied by good deeds, what Aristotle called acts of good authority.
Likewise with BP, we see the apology of the chairman for the Louisiana oil spill but no acts of good authority to accept blame or put things right until they were absolutely forced to.
Like Cameron, previous British Prime Minister Tony Blair made a public apology to the Irish people, that time for the Irish Famine and Britain's shameful neglect at the time.
That too was seen as a great act , because Blair had shown with his work on the peace process that he was utterly committed to solving the Irish question.
Strange to say, but the pope and BP could learn a lot from David Cameron and Tony Blair about how to apologize and mean it.