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Along with college professor and bestselling author, the former Republican Speaker of the House added presidential candidate to his resume today. But if Gingrich wished, he might also include his ranking as an Amazon.com “top reviewer.” Indeed, he hit his peak in 2004 rising into the top 500 of the site’s reviewers, based on how often readers found his reviews helpful. Since then his ranking has slipped, and he hasn’t posted a review since 2008.

“Speaker Gingrich is an avid reader,” says his Amazon profile. “He does not review all of the books he reads. You will not find any bad reviews here, just the books he thinks you might enjoy.”

His fascination with subatomic particles is just one small insight into Gingrich’s character that can be found the 156 book reviews he wrote for the retail Web site over an eight-year period. What else can we learn about the man from his reviews?

Two-thirds of the books are works of fiction, and most of those are mass-market paperback thrillers from writers with top-flight names — John Sandford, Michael Connelly, Robert B. Parker, Tom Clancy.

Gingrich believes these authors can offer profound lessons to American policymakers. 

“All those who said we could never have imagined commercial airliners hitting large buildings had simply not been reading enough adventure fiction. Tom Clancy had a Boeing 747 hit the Capitol in one of his novels,” Gingrich writes in a review of Sean Flannery’s thriller, “Kilo Option,” about terrorists who obtain a submarine.

“Similarly, if at some future time we discover that someone really vicious has acquired a very advanced weapon system by bribing a disgruntled military member of a decaying system, we should not be surprised if we read ‘Kilo Option.’”

Likewise, Brad Thor’s novels “will remind you that our enemies can be more clever, more patient, and more vicious than any think tank’s rational projection of the future.”

With some notable exceptions, Gingrich shows little interest in books by Washington’s A-list politicians, journalists and pundits.

Of note is his review of Bob Woodward’s “Bush at War.”

While Donald Rumsfeld said he never read Woodward’s books about the Bush administration, Gingrich found The Washington Post journalist’s books to be “often worth reading.”

Despite some caveats, Gingrich gave Woodward’s “Bush at War” three stars and wrote that it’s “a good book worthy of every citizen reading it to get a better understanding of the war we are in.”

Perhaps most curious is Gingrich’s fascination with quantum physics.

“To understand fully the future impact on nano-science, and it will be significant, I felt it imperative to try to understand the basics of quantum mechanics,” he writes.

So, from late 2000 to early 2001, Gingrich read several books on the heady subject.

Summing up Richard Feynman’s “QED: The Strange Theory of Light and Matter,” Gingrich writes: “Feynman’s argument is that quantum behavior is truly outside the Newtonian principles of classical physics and contradicts our understanding of the world as we experience it at our large, bulky level.”

“I strongly recommend it,” he ends.

A few other observations:

•Women authored only six of the 156 books reviewed. Spy novelist Francine Matthews wrote two of those books.

•His first review was Mark Bowden’s “Black Hawk Down.” It appeared on April 13, 2000. He last review was of Gordon Rhea’s four volume series on the Civil War, which appeared on Feb. 14, 2008.

•Bill O’Reilly’s novel “Those Who Trespass” was given four stars. “It is a double-edged mystery with a clever New York detective and an attractive New York columnist, who, of course, fall for each other (actually told with more subtlety that I associate with O’Reilly).”

•One coffee table book is reviewed: “Saving the Giant Panda,” by Terry L. Maple. “It is a worthwhile introduction for anyone who cares about conservation in general, pandas in particular or the method by which two countries [China and the United States] can combine government and private activities into effective conservation.”

•28 books are described as being “remarkable.”