"Welcome to the new age of impressionistic history."

Walter Isaacson, former managing editor of Time and chief executive of CNN, reviews James Risen's "State of War" for the NYT:

[Risen's] Page 1 articles in The New York Times exposed, for better or worse, the government's national security wiretapping program. And now he has produced an ''All the President's Men'' inside narrative based on anonymous sources....

So what are we to believe in a book that relies heavily on leaks from disgruntled sources? We are in an age where the consumer of information has to make an educated guess about what percentage of assertions in books like this are true. My own guess is that Risen has earnest sources for everything he reports but that they don't all know the full story, thus resulting in a book that smells like it's 80 percent true. If that sounds deeply flawed, let me add that if he had relied on no anonymous sources and reported instead only the on-the-record line from official spinners, the result would very likely have been only half as true.

In fact, the new way we consume information provides a good argument for the role of an independent press that relies on leakers. Other journalists will and should build on, or debunk, the allegations reported by Risen. This will prompt many of the players to publish their own version of the facts. L. Paul Bremer, the American viceroy in Iraq after the invasion, has just come out with his book pointing fingers at the C.I.A. for giving him flawed intelligence and at Donald Rumsfeld for not giving him the troops he actually wanted. And Tenet, one hopes, will someday cash in on a hefty book contract by clamping cigar in mouth and pen in hand to give evidence that he was not the buffoonish toady Rumsfeld's aides portray him to be. Besides being fun to watch, this process is a boon for future historians.

So welcome to the new age of impressionistic history. Like an Impressionist painting, it relies on dots of varying hues and intensity. Some come from leakers like those who spoke to Risen. Other dots come from the memoirs and comments of the players. Eventually, a picture emerges, slowly getting clearer. It's up to us to connect the dots and find our own meanings in this landscape.

I've elided the part of the review about revealing government secrets, not because I think that's unimportant, but in order to focus on the "impressionistic history" theory -- a theory that bloggers, in particular, might to feel attracted to. Is that a laughably lame excuse for writing a book based on disgruntled anonymities? Or has he got something there?