JUDY WOODRUFF:

Finally tonight, the latest installment in our series of essays.

Tom Nichols, author of the book "The Death of Expertise," shares his Humble Opinion on the demise of experts.

TOM NICHOLS, Author, "The Death of Expertise": A few years ago, a mischievous group of pollsters asked American voters whether they would support bombing the country of Agrabah.

As you might expect, Republicans tended to support military action, while Democrats were more reluctant.

There's only one problem: Agrabah doesn't exist. It's from the animated Disney film "Aladdin." Only about half the people surveyed figured this out, and liberals and conservatives gleefully pointed fingers at each other.

For experts in foreign affairs, however, there was no way around the alarming reality that so many Americans had a well-defined view on bombing a cartoon.

I'm one of those experts. I teach both civilians and military officers about national security affairs. In my career, I have advised the Pentagon, the CIA, and political leaders from both major parties.

Increasingly, however, laypeople don't care about expert views. Instead, many Americans have become insufferable know-it-alls, locked in constant conflict with each other, while knowing almost nothing about the subject they are debating.

How did this happen? How is it that people now not only doubt expert advice, but believe themselves to be as smart, or even smarter, than experienced professionals? Parents who refuse to vaccinate a child, for example, aren't really questioning their doctors. They're replacing their doctors. They have decided that attending the university of Google, as one anti-vaccine activist put it, is the same as going to medical school.

People who have no idea how much the United States spends on foreign aid think that they're the peers of experienced diplomats. Experts in almost every field can tell similar stories.

There's a lot of blame to go around for all of this. The smartphones and tablets that we carry around all day that we think can answer anything are only part of the problem. The American educational system, from grade school to graduate school, encourages students to think of themselves and their views as special. An A is now a common grade.

The news media, while trying to tell people what they need to hear, must compete for ears, eyes, and clicks, and so are also forced to ask them what they'd like to hear.

And even if we manage to avoid the intellectual saboteurs of the Internet, we're still all too likely to get our news and views from social media, where a silly meme from your aunt Rose in Schenectady competes for your attention with actual information.

We need to find our way back from this ego-driven wilderness. Historically, people return to valuing expert views in times of trouble or distress. We're all willing to argue with our doctors until our fever is out of control.

Let's hope it doesn't come to that. But that's where we're headed. And unless we start accepting the limitations of our own knowledge, then each of us is failing in our obligation to participate in our democracy as involved, but informed citizens.