One of the problems plaguing society, and government, is the emergence of people who insist on total adherence to their radical philosophy. And animal activists take it to ridiculous extremes.

Let me state upfront that rigid ideological purity is a destructive disease.

I don’t care whether it’s legal rights for animals or literal interpretation of the Bible — not that those are at opposite ends of the spectrum — it’s neither practical in terms of achieving global objectives nor healthy in terms of personal well-being to demand of everyone else an extreme and unyielding adherence to doctrinaire beliefs.

Such a stance poisons the message, and ultimately, the messengers themselves.

Here’s a perfect example of exactly such a phenomenon.

Our friends at PETA are “calling out” Live Earth co-founder and former Vice President Al Gore for “hypocrisy and sheer laziness” for not limiting the high-profile festival to vegan-only food, according to US News and World Report online.

Let’s break that down.

Live Earth, for those unfamiliar, is a co-creation of Gore, music industry producer Kevin Wall and Pharrell Williams that in 2007 conducted one of those “save the world” super shows featuring live performances in Sydney, London, Kyoto, Japan, and Rio de Janeiro. The goal of the event was raising consciousness about climate change, and the Live Earth II sequel this June will supposedly feature performances across all seven continents (including Antarctica) and be shown on 193 television networks to a worldwide audience estimated at two billion people.

And I trust you know who Pharrell Williams is, right? The hip-hop singer/songwriter/producer whose mega-hit “Happy” from the movie Despicable Me 2 is a favorite of soft-rock radio and middle-aged flash mobs alike.

Earlier this year, Gore, Williams and Wall announced the second Live Earth concert series from the stage at the World Economic Forum in Davos, Switzerland, as a way to generate momentum for action ahead of a UN summit on global warming in Paris in December.

Of course, Live Earth is hardly the first time that music- and movie-industry celebrity performers have conducted some larger-then-life event to raise money/consciousness/awareness for any number of causes, most of them eminently worthy.

However, and this is where ideology rears its ugly head, in a series of emails obtained by folks at the gossipy website BuzzFeed, PETA partisans are pestering the Live Earth organizers to demand that every show on every continent serve only vegan foods.

PETA insisted that Gore, et al, adhere to the letter of their previous statement that, “Dropping meat and dairy products in favor of vegan foods is the best way to reduce our carbon footprint.”

What else would you expect from radicals who pretend that “just leaving animals alone” is the key to solving the world’s problems?

“They either care about stopping climate change, or they’re more interested in the appearance of caring,” Lisa Lange, senior vice president of PETA, stated in an email to BuzzFeed. “While they decide, the earth is dying, so PETA is hoping they immediately announce that they’re putting their mock meat where their mouths are, and making the Live Earth events vegan.”

According to the New York Daily News, a Live Earth representative explained they don’t have complete control over the food served at the venues where their events will be taking place, due to existing agreements between the venues and their vendors.

PETA has no notion of what’s involved on the business side of staging mega-concerts, of course. Ideologues never care about practical details or the realities of the contracts that need to be signed to produce even a minor-league stage show.

But here’s the real irony, and a professional PETA critic since the group’s initial rise to prominence in the early 1980s, I take great pleasure in its incongruity: They’re attacking probably the staunchest supporter of action against climate change in the entire world!

Al Gore, let’s not forget, spent his post-political career producing the “An Inconvenient Truth” roadshow that featured a documentary film, slideshow and book detailing the impact of global warming and recommending strategies to reverse its effects on everything from ocean acidification to violent tropical storms to the expansion of desertification and its impact on agriculture.

Gore was the principal force behind the original Live Earth event, and PETA’s ripping him for not being pure enough because he won’t make vegan food a non-negotiable clause in the agreements necessary for a simultaneous series of concerts to take place on the same day in multiple locations around the world — events to be attended by ticket buyers who are 99.99 percent non-vegan.

PETA’s not only clueless, they look seriously vindictive in trying to steer such a mega-event onto a narrow, ideologically pure pathway.

It won’t happen, of course, but I’m willing to bet that PETA’s extremist-when-it-gets-us-publicity leadership— and their zombie army of brain-dead followers — are actually feeling good about their ridiculous and self-defeating ploy.

Because that’s what they do for a living.

While the rest the most activist community has only two options: Dismissal or denial.

Dan Murphy is a food-industry journalist and commentator