Thinking in public is a difficult habit to get into, though, because public is the place where we're supposed to not screw up, and thinking on the fly inevitably involves screwing up. Blogging with any regularity in essence means committing oneself to making one's intellectual fallibility visible to the world and to the unforgiving memory of the Google cache. This is particularly a problem for academics, who are, after all, professional thinkers; we have a culture of making it look easy, and of concealing as much as possible "the raw material of poetry in all its rawness."
At Least I Won't Be Unoriginal
Blogging lets people think in public in a way that's refreshing. Intelligence is not the property of universities, fancy magazines, and literary journals.