I think I know who Deep Throat is.

Am I positive? No. Able to swear on a Bible, willing to wager the contents of my 401(k)? No. But on a scale of one to ten, with one being uncertainty and ten being total confidence, I probably reside at nine, which means I am willing and able to devote today's column to the subject. Deep Throat's name will appear in the last paragraph. Do not skip ahead. And try not to be disappointed.

First, my sources. There are three. Common sense. David Obst, former literary agent of Bob Woodward and Carl Bernstein and author of the memoir, Too Good to Be Forgotten. And a man whose name I will not reveal, a name known to millions, but to whom I will refer in the lines ahead, intending no disrespect, as Shallow Throat. 

And yes, I am aware of the irony, if not the apparent hypocrisy, of citing an anonymous source to unmask an anonymous source. 

Here is the story as it has come to me: 

When Woodward and Bernstein wrote their newspaper articles on the Watergate scandal, they did not mention Deep Throat. When they handed in the first draft of their book, All the President's Men, an expanded version of their Watergate reportage, they did not mention Deep Throat. 

Yet in the book as eventually published, there he was. And there he also was in the movie version, played by Hal Holbrook, all terse and cryptic and backlit, standing in the shadows of an underground parking garage, whispering such helpful hints as "follow the money." 

Deep Throat was born, then, in the first or second rewrite of All the President's Men, which appeared in bookstores in June of 1974. That makes the date of conception late 1973, when Woodward and Bernstein were polishing their prose and imagining their fame, and their editor at Simon and Schuster, sensing that she had a potential blockbuster on her hands, was doing all she could to help. 

She seems to have had two objections to draft number one. This, at least, is what Shallow Throat thinks, and what he told me one day in the presence of others. 

First, so thorough was Woodward and Bernstein's reporting, so diligent were they in assembling their facts, that it seemed as if an army had been employed in research; readers might not believe that so great a quantity of information had come from a mere pair of foot soldiers. 

Second, so familiar were most of the details, because of all the reporting previously done on Watergate, that the manuscript was a little flat; it lacked punch, pizzazz, the element of surprise. 

So the editor got an idea, a one-stoner for the two birds. Make up a character, she suggested. Fabricate a fellow. Create a person who met with Woodward and Bernstein on a number of clandestine occasions and imbue him with voluminous knowledge and a furtive pedigree. The former would make the authors' own knowledge seem credible, while the latter would add some suspense to the tale: Agatha Christie meets Ben Bradlee. 

Actually, let's call it three birds. The addition of a mystery-cloaked source made All The President's Men a more appealing property to Hollywood. Robert Redford and Dustin Hoffman, who played Woodward and Bernstein in the movie, and director Alan J. Pakula were reported to have found the early, Deep Throat-less manuscript overly journalistic, insufficiently cinematic. They, too, welcomed the new guy in the parking garage. 

Shallow Throat does not know how the real-life Woodward and Bernstein reacted to their editor's suggestion. He speculates that they rebelled initially, insisting they were reporters, not novelists. But eventually they gave in; as first-time authors, they could not disregard the wishes of one of the biggest publishing houses in the world. 

Further, he says, they were persuaded that Deep Throat would not alter any of the basic truths of their book. He might be a lie, but what he spoke was a matter of record. 

So there you have it. Deep Throat does not exist. Or, to put it another way, he is a composite, since the tips and leads and guidance attributed to him were provided to Woodward and Bernstein by a variety of others. 

Or to put it one more way, the most mysterious human being to appear in American non-fiction in the past three decades is not a human being at all; he is a literary device, like alliteration or onomatopoeia or metaphor, the brainchild of one of the most respected and successful editors in the entire world of publishing. 

Her name: Alice Mayhew. And if Shallow Throat and I are right, never before has so anonymous an "author" been responsible for so famous and enduring a character.