Prison is largely ineffective for rehabilitating sex offenders, retired Supreme Court judge Catherine McGuinness has said.

Although sexual offenders should “absolutely” be given some sort of punishment, jailing them for many years serves little purpose, Judge McGuinness said.

Judge McGuinness (83) was speaking to The Irish Times after being awarded an honorary doctorate from the Royal College of Surgeons in Ireland for her role in Irish political, legal and social life.

Over the years she has served as a Labour senator, a barrister and a judge of the Circuit, High, Appeal and Supreme Courts. She has also chaired the Forum for Peace and Reconciliation as part of the Peace Process and served as president of the Law Reform Commission.

“There are so many criticisms of sentencing. And it’s always from a hang-em and flog-em point of view. No one ever says you should give them a lighter sentence. They never think about the way you have to approach sentencing and the things you have to take into account.”

Referring to the recent sentencing of former Irish Times journalist Tom Humphries to 2½ years for child sex abuse, Judge McGuinness said she believed the sentencing judge, Karen O’Connor, “did that case very well”.

There has been widespread criticism of the leniency of the sentence and calls for the Director of Public Prosecution to appeal it. Much of the criticism centred on the sentencing judge’s comments that “it was hard not to have some sympathy” for the accused given his fall from grace. “She actually approached that sentence completely along the proper guidelines,” said Judge McGuinness. She added that the judge was obliged to take the loss of Humphries’s position into account.

“That man, his life has totally been destroyed too. I mean, of course he shouldn’t have been doing what he did. But his life is completely destroyed too. Jail is neither here nor there to some extent,” she said.

“For sexual offenders I don’t think jail does them much good anyway.”

She added that the offence “absolutely should be marked with some sort of punishment. I don’t think you can let people off with nothing. And sometimes there are sentences that are too small”.

She continued: “But I thought she did very well. I don’t think for a minute he should be put in prison for years and years and years.”

Jury trials On the subject of defamation law, Judge McGuinness said consideration should be given to abolishing jury trials in such cases.

Defamation is the only area of civil law in the High Court which still uses a jury. She said juries tend to give “ginormous awards” in defamation cases. She recalled one case she handled which was taken by businessman Denis O’Brien against the Irish Daily Mirror newspaper.

The jury awarded Mr O’Brien €250,000. This was later overturned by the Supreme Court as excessive. When a High Court jury was asked to reassess the damages, it tripled the award to €750,000.

Shane Ross On the subject of reform of judicial appointments, Judge McGuinness said she agrees with the position taken by former Chief Justice Susan Denham and most senior members of the judiciary that judges must have a bigger role in selecting their colleagues.

Minister for Transport Shane Ross has championed a judicial appointments Bill which would see judges appointed by a committee which would have a lay majority and a lay chair.

“Don’t get me started on Shane Ross ... I have a low view of Shane Ross,” Judge McGuinness said.

She said it was true that the changing of the pension rules means the best lawyers are not always interested in becoming judges, although she would not go as far as Senator Michael McDowell in saying the quality of judges has declined as a result.

“Don’t get me started on Shane Ross”: The Minister for Transport has championed a judicial appointments Bill which would see judges appointed by a committee which would have a lay majority and a lay chair. Photograph: Alan Betson / The Irish Times A judge now has to serve 20 years before being entitled to a full pension, up from the previous 15 years.

“In order to retire at 70 you have to start at 50. And 50 in my view is the wrong time to start. You’d be better to appoint them a bit later than that because at 50 they’re at the top of their career and they don’t really want to go into the judiciary.”

Sexual harassment Asked about the recent sexual harassment scandals, Judge McGuinness said she did not experience harassment as a barrister but said that might be because she was 40 when she came to the bar and was “well able for them by that stage”.

“There was a fair bit of sex in the bar,” she said. “There were relationships between barristers, male and female barristers, and for all I know male and male, and female and female barristers.

“But they were consensual relationships. Some of them were adulterous relationships alright, but they were consensual.”

Judge McGuinness: In quotes On Shane Ross “I was in the Senate with Shane Ross for quite a long time. As far as I remember, myself and Mary Robinson refused to sit beside him. We just didn’t like him. Not because we felt he was doing anything bad to us. We just disagreed with him profoundly, with his own outlook on life.”

On gender equality “It’s interesting that we have got a much higher proportion of female judges than you get in England. And I’m afraid that’s largely because of political appointments. Because it’s the Government appointing them and they’re consequence of the need for gender balance. If you had judges being appointed by the Bar Council, believe me there wouldn’t be one woman.”

On whether she was a political appointment due to her Labour connections: “No, Labour never had enough power.”

On sexual harassment in the Law Library “I was the sort of person who was able to bat them off quite well. I might have given them a slap or something if that had happened but it genuinely never happened there.”

On retirement from the Supreme Court in 2006 “I was very sad to retire. But I had to go, they throw you out at 72. When I first left I would drive by the Four Courts and really miss it a lot. Because you lived there. It was a really interesting life to live.

On the role of the internet in trials “I sometimes think ‘thank God I’m out of that’. It must be very tempting for jurors to go home and Google some fella. It’s very hard to stop them.”