But Sullivan’s departure from the blog world is a good moment to reconsider a revolutionary form that has matured–and to think about what is essential about blogs and makes them likely to endure. (Credit, or hat-tip, as bloggers might put it, to this question of essential nature, is due to the Greek philosopher Plato, and a reminder that even when writing about new technology, it always helps to have a grounding in the classics of humanities.)

The pajamas—what bloggers other than myself were widely reported to wear as they typed away—aren’t essential. But blogs are well positioned to survive, in part because a blog is about an individual, not an institution, in an era when individuals matter more than institutions.

The value to the reader of a blog is provided by the individual journalist, not the brand for which he or she happens to write. Andrew Sullivan’s readers followed him from AndrewSullivan.com to Time, the Atlantic, and the Daily Beast. People read Jeffrey Goldberg’s reporting on the Middle East because it is by Jeffrey Goldberg. It doesn’t matter to readers whether it appears in The New Yorker, Atlantic, or Bloomberg View. Paul Krugman’s readers don’t care whether he is writing in Slate, The New York Times, or The New York Review of Books. If Krugman left The New York Times and started writing for the Washington Post, readers would follow him there, just as technology columnist Kara Swisher’s readers followed her from the Wall Street Journal to Recode.