[I]f you're of a mind to, you can trace [blogs'] print antecedents a lot further back than [Herb] Caen or Hunter S. Thompson. That informal style recalls the colloquial voice that Addison and Steele devised when they invented the periodical essay in the early eighteenth century, even if few blogs come close to them in artfulness. . . .Geoffrey Nunberg, “Touched by the Turn of a Page,” in The Years of Talking Dangerously (New York: PublicAffairs, 2009), Kindle ed. location 1401
For that matter, my Language Log co-contributor Mark Liberman recalls that Plato always had Socrates open his philosophical disquisitions with a little diary entry, the way bloggers like to do: "I went down yesterday to see the festival at the Peiraeus with Glaucon, the son of Ariston, and I ran into my old buddy Cephalus, and we got to talking about old age. . . ."