Renowned historian and former Irish senator Professor John A Murphy, has expressed concern we are moving into a new age of puritanism. This worries him, since he is old enough to remember the old puritanism when the word 'breast' could get a book banned and a Doris Day movie which contained the expletive "darn!" was registered as indecorous, if not actually shocking.
But if there is a new puritanism, then it's probably a reaction against the previous liberalism, known as "the permissive society". Two men died earlier this month whose lives symbolised, rather well, that era of libertinism: Victor Lownes (88), the most influential executive of Hugh Hefner's Playboy empire; and Lord Snowdon (86), Princess Margaret's former husband.
I wouldn't want to be unkind about Tony Snowdon, who was obliging to me when I was researching a book about the British royals and Ireland, and who spoke affectionately about his boyhood visits to Birr in Offaly, where his mother was the Countess of Rosse. The Rosse tradition of science and technology helped Snowdon as a boy, when he discovered a Victorian photographic studio in Birr Castle.
Later, he brought Margaret to Birr - the first visit by a British royal to the Irish Republic, and it served as an ice-breaker in Anglo-Irish relations.
However, the standard obituaries (and biographies) do make plain that Tony Snowdon and his royal wife were much identified with Swinging London, which included wild parties, copious alcohol, soft drugs, and a liberated attitude to sex. Fidelity was not a strong aspect of the Snowdon marriage, and affairs were embarked upon. Tony Snowdon always had other girlfriends and he fathered a couple of sprogs outside of wedlock. I don't say this judgementally, as I'm in no position to judge anyone: it's just a description of a lifestyle that is vividly illustrated by Anne de Courcy's frank and revealing Snowdon biography.
There have always been royals and aristocrats who did exactly as they pleased when it came to personal relations: Charles II left 19 illegitimate children, and his last words were for his mistress Nell Gwynne. And, significantly, the swinging 1660s directly followed on from the puritan age of Cromwell, when all entertainments were regarded as decadent and scoffing a mince pie was a sin of gluttony.
But the 1960s extended a kind of gender equality in the realm of sexual liberation. That was the theory, once the contraceptive pill promised a new era when sex would be free from restraints such as the fear of unwanted pregnancy.
Hugh Hefner and his chief lieutenant Victor Lownes saw their opportunity with the launch of Playboy and the various Playboy clubs, where women were done up like bunny rabbits, squeezed into corsets which emphasised butt and bosom.
Hefner said it all when he proclaimed that the pill meant "sex was now about recreation, not procreation". Serious Christian thinkers who tried to portray the pill as a responsible means of spacing children and of improving the health of mothers were soon outpaced by the Playboy philosophy which underlined that sex was not just for fun - it was also good for business: it sold things.
Lownes, who came to London in 1972 to set up the Playboy empire on this side of the Atlantic, announced as his mission statement: "Privately, publicly and commercially, I think sex is good." He filled his London mansion with bunny girls for his delectation: one of his parties went on for 25 hours, during which 2,000 guests consumed 8,000 bottles of champagne and celebrities 'cavorted' with the said bunnies. Peter Cook, Mick Jagger, Warren Beatty, Roman Polanski, Keith Moon, Ringo Starr, Clement Freud, among others, were all seen at Playboy parties.
The bunnies were seldom identified by name, except the bunny who became Mrs Victor Lownes eventually: she was known as Marilyn 'Boobs' Cole.
Germaine Greer has explained that people sometimes confuse the sex revolution with the feminist revolution. They had certain common themes - personal liberation was one - but they were not the same.
The feminist revolution started as a reaction against the likes of Playboy, where women were quite evidently treated as sex objects. Gloria Steinem was the first to expose the humiliating way in which the Playboy bunnies were seen - she went undercover and became one.
For feminists, the pill was about women controlling their fertility. For the Playboy philosophy, contraception was about keeping women sexually available, without the nuisance of having to take responsibility for any consequences.
If we are seeing stronger awareness of the need for consent in sexual relations, a right not to be assailed by pornography or offensive material, concern about rape and sexual harassment, then it surely follows from the way in which the Playboy world advanced sexual freedom.
The new President of the United States has been, regrettably, part of that Playboy philosophy: he is proud to have posed on the front cover in a 1990 edition of the magazine.
The way in which he has spoken about women in the past is all part of the picture.
He has been made to realise he is now in a different era: Victor Lownes is dead, Hugh Hefner is 90 and fragile, and we are, possibly, in a new puritan age.
Action and reaction always follow.