It's a dangerous world in which to speak your mind.

To quote from June's Economist: "From the mosques of Cairo to the classrooms of Yale, all sorts of people and groups are claiming a right not to be offended ... A right not to be offended implies a power to police other people's speech."

I have often commented on our overly sensitive and easily affronted society especially, it seems, if the offending speaker is an older white male, yes, like me. But not exclusively. Ask Germaine Greer or Chrissie Hynde.

In the past unreconstructed dinosaurs could often be relied to make prats of themselves over gender and race issues but now everyone is on notice. The boundaries are shifting daily it appears, and being educated, smart and hip doesn't make you less of a target.

Take for instance the story of Kiwi executive chairman of global advertising firm Saatchi & Saatchi, Kevin Roberts, whom I would not normally leap to defend.

He was forced to resign this week over his comments about gender imbalance in the advertising and media industry.

Photographer: Martin Miranda Kevin Roberts, head of Saatchi and Saatchi, in the dog box for some mild comments.

Roberts' horrific crime was telling a business publication he didn't think gender diversity was as big an issue in the industry as some were suggesting.

He did not denigrate women or say they were any less useful than men. He simply challenged a prevailing view about diversity.

Then we have hip craft beer brewer Moa which was thinking about promoting its beer with a talking beer bottle that drawled on about botox in a southern accent.

Supplied Businessman Geoff Ross has been forced to defend claims his beer company is misogynistic.

That lifted the lid on its whole advertising campaign which chief executive Geoff Ross had to defend against charges of misogyny, even if three out of four images on Moa's new beer can range featured fully clothed women engaged in outdoor activities.

Last week it was University of Canterbury sociology professor Greg Newbold's turn.

The University's Feminists Society (FemSoc) complained about a lecture he gave to promote his latest book.

His lecture about feminist campaigns in the 1970s and 1980s and their impact on rape law apparently left some attendees "visibly disturbed" and "likely in shock at the inappropriateness", according to the complaint.

The complaint accused Newbold of objectifying women and contributing to rape culture by saying New Zealand's penalties for rape were too drastic and failed to address the impact on victims.

Newbold's shocking comments were answers to some "thorny" questions from the floor during question time, it turned out.

"The matter of rape is always controversial, but in declaring that the lecture content should have been vetted, the dissenters seem to think university staff should not be able to voice opinions that they personally disagree with," Newbold later wrote.

"They appear unaware that the university is an institution where freedom of expression and open debate is part of its core business."

So what is happening?

Are we seeing calls for a more respectful and polite public discourse or are we experiencing a more zealous move to sanitise public discussion to avoid affront and hurt?

It's looking very much like the latter. In other words, valid if provoking opinion is starting to be regarded in the same way as hateful views.

A similar debate is raging across university campuses in the United States where elite universities have banned speakers prepared to challenge politically correct thinking and students have demanded safe places and the removal of some academics.

The boundaries of what counts as acceptable debate will shift with changing times but the range of opinion or comment that is regarded as deserving of condemnation seems to be widening quickly. The test is not objective and condemnation is not enough. People must be removed, silenced, censured and sacked.

When some of the complaints should be laughed out of court, they are treated by companies and institutions as serious and destablising. In Roberts case, the parent company issued a predictable statement saying it "will not tolerate anyone speaking for the organisation who does not value the importance of inclusion".

Canterbury University made noises about academic freedom carrying certain responsibilities, expectations and accountabilities.

It won't be long before the university is putting cautions in books and texts to warn students of potentially upsetting bits coming up.

It would all be very droll – a very first world issue – but for some potentially harmful ramifications.

The first is that debate will obviously become more limited and one-sided. The sometimes ugly and painful exchanges that lead to change will be stifled.

With jobs, careers and reputations at stake, people who want to speak up will stay silent, keeping their heads below the parapet. They will self censor.

On the surface it will appear the zealots have succeeded in changing attitudes when all they have achieved is driving those views they find offensive underground.

That won't benefit the zealots or those holding those discomforting views. Opinions and positions will become more entrenched as they breed like viruses in their only little petri dishes. Censorship favours the status quo, it is said. Ask China.

Then all of a sudden someone like Donald Trump, who doesn't give a fig for civilised rules of discourse, comes along and finds a willing audience in those who feel they have somehow lost a voice.

What happens in universities and in boardrooms is important because it influences those on the outside.

The principle of free speech can sometimes be used to defend the indefensible but it certainly shouldn't be curtailed to avoid hurting the feelings of over-sensitive people whose views are often as unreasonable and entrenched as those of the very people they despise.

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