Samuel Pepys, thou shouldst be living at this hour, in Dublin if you could afford it, which you probably could, being blessed with friends who'd give you a dig-out and expect no favours in return.

If Pepys were in Dublin, he'd join Fianna Fail. He was as prolific in philandery as in keeping a diary. Would nip out from the office mid-morning, have his way with a woman and be back for an hour's labour on the ledgers before lunch. After which, he'd work for another while and then visit his mistress, before returning home to his family, tired but happy. A Soldier of Destiny, surely, but that's by the by.

As Britain's chief naval administrator, Pepys organised procurement of materials and provisions for the fleet. Timber moguls, rum merchants and the like called regularly to his office at Greenwich. Some might (if they found him in) present him with small bags of gold coins.

Pepys once explained to old friend Peter Luellin, who was urging him to buy timber from a forest his employer had stolen in Ireland and who had just handed him 50 gold pieces and a promissory note of £200 a year: "I would not sell my liberty to any man. If he would give me anything by another's hand, I would endeavour to deserve it, but I will never give him thanks for it, nor acknowledge the receiving of it ... I did also tell him that neither this nor anything should make me to do anything that should not be for the King's service besides."

Charlie Haughey said as much to Ben Dunne.

In his final speech to the Dail, Mr Haughey also said that: "I have done the State some service." A third thing said by Mr Haughey was that of all the operators he'd ever known in Fianna Fail, Bertie Ahern was "the most skilful, the most devious, the most cunning of them all."

Whether it was cunning of Mr Ahern to cut up so rough at the Mahon Tribunal this week is another matter.

The tribunal is inquiring into claims that Mr Ahern, when Minister for Finance in 1994, took a large sum of money from businessman Owen O'Callaghan, then lobbying to have a shopping development he was involved in given an advantageous tax designation. The allegation originally came from rival developer Tom Gilmartin. Mr Ahern and Mr O'Callaghan deny the charge. No evidence to sustain it has emerged.

Searching for the facts, Justice Mahon felt it necessary to examine the pattern of lodgements and withdrawals in Mr Ahern's bank account around the relevant time. It is this 'trawl', and the leaking of material arising from it, which has enraged Mr Ahern's supporters and prompted suggestions of a campaign to blacken his reputation. On Monday, barrister Conor Maguire accused the tribunal of "actions ... bound to create a serious risk of an interference with the democratic process".

Justice Mahon responded that: "The tribunal has ... found it necessary to probe - and to only probe - those significant lodgements which appear in his account and which were not accounted for by his income."

There, in a phrase, is the problem which will face Mr Ahern when he gives evidence to the tribunal, probably late this year, probably as Taoiseach. His explanation of heavy traffic through his bank account in the period does not strike all observers as plausible.

Take the IR£28,772 lodged at AIB's O'Connell Street branch on Mr Ahern's behalf in December 1994. Mr Ahern says this represented £30,000 which a friend, builder Michael Wall, had unexpectedly handed him in cash in his office earlier the same month to pay for renovations to a house owned by Mr Wall which Mr Ahern was later to rent and then to buy.

However, the total in sterling exchanged at the AIB branch that day was £1,922.55. Moreover, IR28,772 at the prevailing rate did not equate to £30,000. It did equate, exactly, to $$45,000.

Mr Ahern says that he has never dealt with any such large sum in dollars, and no evidence to contradict this has been produced.

Mr Ahern will be questioned about a scheduled meeting in Los Angeles in March 1994 with investment bankers Chilton & O'Connor, then representing Mr O'Callaghan, who, at the time, was proposing a £50 million project at Neilstown in west Dublin.

Asked last September about the Los Angeles meeting by Jody Corcoran of the Sunday Independent, Mr Ahern said that he had no memory whatever of any such meeting.

Tribunal lawyer Des O'Neill warned on Monday that people should not reach any conclusions about the bank transactions. "There may be an explanation for them." Indeed there may, and we will hear it from Mr Ahern.

A sizeable section of the Dublin commentariat believes that hardly anybody cares about this stuff. Bertie saw off his accusers during the election campaign. The only jury that matters supported him. What's needed now is five years of growth and stability. All this nit-picking begrudgery is a distraction.

Maybe. My own powers of prediction in Free State affairs are pathetic. A week ago, I was telling anybody who'd listen to get locked on the Shinners at 7-1 to take 13 seats or more. So I'm probably wrong when I reckon that the Mahon Tribunal might do for Bertie.

Pity he didn't keep a diary.