JUDY WOODRUFF:

Now: Has faith in the power of reason fallen victim to modern politics?

Ten years after its original publication, former Vice President Al Gore has updated his book "The Assault on Reason." Its new subtitle is telling: "Our Information Ecosystem: From the Age of Print to the Age of Trump."

I sat down with him this afternoon, and started by asking about the sharp criticisms he made in the original version against then President George W. Bush.

AL GORE, Former Vice President of the United States: My criticisms were not mainly aimed at any individuals, including President George W. Bush or Vice President Cheney, but rather the way in which our democratic conversation has been degraded over the last several decades.

And I would say the same thing about President Trump. For me, the most serious problem is how our nation became so vulnerable to the assertion of blatant falsehoods that drive policy and are not corrected by the so-called immune system of democracy, a free press and a free democratic discourse.

And I think we have a huge systemic problem that we have largely ignored. When our founders created America, it was in the age of the printing press, when individuals could freely join the conversation. And that robust, democratic dialogue more often than not lifted up the best available evidence and asserted what was more likely to be true than not.

Now we have things that are obviously false, leading us to war, leading us to deny people health care, leading us to ignore the climate crisis. We have to restore the integrity of the democratic conversation.