The sale of The Washington Post to Amazon.com founder Jeff Bezos has prompted intense discussion of the future of journalism. That discussion has yet to focus on a remarkable feature of the Post and other old-fashioned newspapers: They provide people with a great deal of content that they wouldn't have chosen in advance.
Newspapers create what we might call an architecture of serendipity, in which readers encounter all sorts of stories, facts, ideas and opinions that they didn't select. Much of what they encounter seems boring, irritating, wrong or offensive, but on occasion it turns out to be surprising, delightful, alarming, important and even life-changing.
A lot can be said on behalf of serendipity. In your daily newspaper, you might learn about a new book - on neuroscience, say, or folk music - and, to your great surprise, it might pique your interest and broaden your horizons. You might run into a story on how to improve your health or save for retirement, and it might lead you to alter your habits, even if you don't much like thinking about your health or your retirement.
You might see a story on Syria, and it might move you, maybe even alter your life, even though you couldn't have imagined yourself being interested in Syria. Well-run newspapers offer stories that intrigue, entertain and affect readers who come across those stories only by happenstance, not because they ordered them in advance.
An architecture of serendipity seems old-fashioned today, an artifact of the technological limitations of a bygone era. The wave of the future is an architecture of control, through which consumers get to see, read and hear exactly what they want and avoid what they don't want. Modern technologies make it easy for providers of goods and services to engage in personalization, which means they can tailor their products to people's specific tastes.
Bezos has mastered this point. Amazon learns what you like, and it makes recommendations for you based on what you like. In 1998, Bezos made the point explicitly: "If we have 4.5 million customers, we shouldn't have one store. We should have 4.5 million stores."
Can't the same be said of newspapers? If the Post has 19 million readers, could it have 19 million newspapers?
In the newspaper business, complete personalization hasn't yet arrived, but it may be on its way. For example, Facebook has created a news feed, with a secret algorithm, that uses your previous clicks to make selections for you. Mark Zuckerberg has said that the feed will operate as a "personalized newspaper." Then there's News360, an application that monitors what you choose to read and "by learning what you enjoy, brings you content that you'll find interesting and important."
Why shouldn't people see what they want? The best answer is that in communications, as in daily life, serendipity is highly desirable - an important part of freedom and self-government, not an obstacle to them. Those who read only what they identify in advance end up narrowing their horizons; they may create echo chambers of their own design.
When like-minded people speak only with one another, they tend to go to extremes, thus aggravating political polarization. An architecture of serendipity can reduce that effect. It can also create a kind of social glue, by creating common understandings and experiences for members of a highly diverse nation.
It is ironic that old-fashioned newspapers served some of their most important social functions only because of technological limitations, which prevented them from giving their customers only what they want. Those limitations are a thing of the past. But it is critical, for individuals and societies alike, that newspapers continue to provide readers with the experience of serendipity.
Cass R. Sunstein is a professor at Harvard Law School and a Bloomberg View columnist.