When it comes to protecting science and objective reality, former President Barack Obama has no idea where to start - all he knows is that there is a problem and it needs fixing.

Obama has largely stayed away from the political stage since leaving office, but this week, during a speech in South Africa, the former president could not hold his frustrations in any longer. Speaking in honor of the late Nelson Mandela, Obama launched a passionate and much-needed defense of facts.

"You have to believe in facts. Without facts there's no basis for cooperation," he said in his speech.

"If I say this is a podium and you say this is an elephant, it's going to be hard for us to cooperate."

As funny as the joke is, Obama's remarks address a serious problem in society at the moment - namely the unquestioned rejection of an objective reality in favor of just about anything. Experts are referring to this phenomenon as the 'post-truth' era, a time when the public is struggling to distinguish between fact and opinion.

When it comes to science, the problem is particularly well-documented, with too many Americans dismissing robust data on issues like anthropogenic climate change and the safety and efficacy of vaccines. For a self-professed pro-science president, the problem is particularly baffling.

"I can find common ground for those who oppose the Paris Accords. For example they may say, it's not going to work…or they may say it's more important to provide cheap energy for the poor even if it means more pollution," he said.

"At least I can have a debate with them about that and I can show them why I think clean energy is the better path."

Obama explained, however, that his olive branch can only extend to those who are willing to accept reality.

"I can't find common ground if somebody says climate change is just not happening, when almost all of the world's scientists tell us it is," he said.

"I don't know where to start talking to you about this. If you start saying it's an elaborate hoax, where do we start?"

But Obama's accusations were not just leveled at the public, he also placed the blame firmly on the shoulders of politicians.

"People just make stuff up. They just make stuff up. We see it in the growth of state sponsored propaganda. We see it in internet fabrications. We see it in the blurring of lines between news and entertainment," he said.

"We see the utter loss of shame among political leaders where they're caught in a lie and they just double down and they lie some more. It used to be that if you caught them lying, they'd be like, oh man — now they just keep on lying," he added, amid laughter from the crowd.

Obama warned that in the political ring, this rejection of reality puts the very basis of democracy in grave danger.

 "We see it in the promotion of anti-intellectualism and the rejection of science from leaders who find critical thinking and data somehow politically inconvenient," he said.

"And, as with the denial of rights, the denial of facts runs counter to democracy. It could be its undoing."

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