As you read a log, you have the curious sense of moving backward in time as you move forward in pages—the opposite of a book. As you piece together a narrative that was never intended as one, it seems—and is—more truthful. Logs, in this sense, were a form of human self-correction. They amended for hindsight, for the ways in which human beings order and tidy and construct the story of their lives as they look back on them. Logs require a letting-go of narrative because they do not allow for a knowledge of the ending. So they have plot as well as dramatic irony—the reader will know the ending before the writer did.

Anyone who has blogged his thoughts for an extended time will recognize this world. We bloggers have scant opportunity to collect our thoughts, to wait until events have settled and a clear pattern emerges. We blog now—as news reaches us, as facts emerge. This is partly true for all journalism, which is, as its etymology suggests, daily writing, always subject to subsequent revision. And a good columnist will adjust position and judgment and even political loyalty over time, depending on events. But a blog is not so much daily writing as hourly writing. And with that level of timeliness, the provisionality of every word is even more pressing—and the risk of error or the thrill of prescience that much greater.

No columnist or reporter or novelist will have his minute shifts or constant small contradictions exposed as mercilessly as a blogger’s are. A columnist can ignore or duck a subject less noticeably than a blogger committing thoughts to pixels several times a day. A reporter can wait—must wait—until every source has confirmed. A novelist can spend months or years before committing words to the world. For bloggers, the deadline is always now. Blogging is therefore to writing what extreme sports are to athletics: more free-form, more accident-prone, less formal, more alive. It is, in many ways, writing out loud.

The Atlantic