The late Christopher Lasch once wrote that public affairs generally and journalism in particular suffered not from too little information but from entirely too much. What was needed, he argued, was robust debate. Lasch, a historian by training but a cultural critic by inclination, was writing in 1990, when the Internet was not yet a part of everyday life and bloggers did not exist. Bloggers now are everywhere among us, and no one asks if we don't need more full-throated advocacy on the Internet. The blogosphere is the loudest corner of the Internet, noisy with disputation, manifesto-like postings and an...