Democracies around the world are under threat from populist movements, demagogues, and dogmatic extremists who use disinformation, conspiracy theories, shaming, cancel culture, and other tactics to weaponize social media and challenge our ability to distinguish fact from fiction and truth from falsehood.

In his new book, our guest, best-selling author, journalist, scholar, and public intellectual, Jonathan Rauch, offers a stirring defense of the constitution of knowledge— our social system of checks and balances that is crucial for turning disagreement into truth.

"This global network of people hunting for each others' errors is far and away the greatest human technology ever invented," Jonathan tells us in this episode of "How Do We Fix It?" The constitution of knowledge, he says, "is a global conversation of people looking for truth, and more especially, looking for the error."

When social media burst on the scene, many of us were in awe of its great potential. For the first ten years of Facebook, public reaction to this new form of communication was overwhelmingly positive, but now that we have a better understanding of how social media is shaping our world, there are growing calls for fundamental reform.

Should tech monopolies be cut down to size and broken apart? Or is a much more careful, nuanced approach needed from Congress?

MIT Management Professor Sinan Aral has spent two decades studying how social media changed American politics, the economy, and even our personal health. He is the author of the recent book, "The Hype Machine". As an entrepreneur and investor, he has a deep understanding of the perils and promise of social media. We publish extracts from his interview with the podcast, "Democracy Works".