Maher pressed Obama on a host of issues that, as the comedian noted, he may not usually be asked to field, such as atheists’ political clout and the American foreign policy empire. And the pair also tackled concerns like the threat of opioid addiction, the efficacy of GMO crops, and the politically-motivated tension between science and religion that can breed misinformation and a dumbing down of basic facts.

Bill Maher is a well-known atheist and outspoken advocate for non-believers. So it makes sense that he broached the topic of religiosity with Obama, suggesting that atheists don’t get a whole lot of respect in the political realm.

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The president responded that the real problems arise when faith is used as a political cudgel to dilute hard facts and scientific consensus—part of a concerning trend that Obama suggested was a “balkanization” of the media and reality wherein everything becomes debatable and subjective, no matter how much empirical evidence is present, as has happened with climate change. (As I’ve previously reported, Donald Trump’s running mate, Indiana Governor Mike Pence, has some truly bizarre views on modern science.)

“Our kids are growing up in an environment where everything’s contested, where nothing is true,” said Obama. “Because if it’s on Facebook, it all looks the same. And if you’re reading something from a Nobel Prize-winning physicist next to some guy in his underwear writing in his basement or in his mom’s basement, in context it looks like it’s equally plausible.”

Obama specifically called out the politicization of certain school boards, which has led to what the president called a “watering down” of science in educational curricula.

But the president also noted that anti-science, anti-fact tendencies are bipartisan, especially when it comes to issues like food purity and the safety of genetically modified organisms (GMOs). (He didn’t mention the anti-vaccine crowd, which also has a number of high-profile liberal members.)

“Now I will tell you, and this may be controversial to some in your audience, it is important to look at the science on this stuff,” he said. “So, when it comes to antibiotics for example, the science is clear we pump our animals full of it. And that’s not just a problem in what we’re ingesting—it’s also a problem that more and more bacteria’s becoming resistant to antibiotics.

“But in some cases, for example the GMO debate, there are areas where there are legitimate concerns, there are some areas where the science seems to indicate, well, this is okay…” he continued. “My point is we have to make sure that what we’re doing, whether on the left or the right, is being driven by the science. And if it turns out that some of these genetically modified foods aren’t healthier, aren’t more productive, then we should follow the science. If in some cases they’re not causing any harm, then we should follow the science there, as well.”

Another example of raising science’s relevance in the policy debate, Obama noted early in the interview, was approaching the drug war through a public health (rather than a criminal justice) lens, which studies have shown would be much more effective in fighting the opioid addiction epidemic.

Obama’s overall argument was that, while political and policy opinions are inherently debatable, there is such a thing as objective truth and facts governed by instruments like science—and that rejecting this notion can lead to an epistemological rift in society that’s nearly impossible to bridge.

“What I always say to my teams is, figure out what is right, as best as we can tell,” he said. “And then once you’ve figured that out, then we’ll worry about the politics, after that. Don’t start with the politics and then try to get the facts to fit in with the politics. At minimum what that does is it keeps us tethered to reality.”