The life of the presidential mind. Photo: Ron Sachs/Bloomberg via Getty Images

We know from reporting about the Trump administration, from an overheard comment before the State of the Union address, and from President Trump’s own Twitter feed that Trump is very excited about the Devin Nunes memo. We know Trump believes the memo discredits the FBI as a tool of the biased deep state, provides him with a pretext to interfere with or close down the Mueller investigation, and wants it released to the public.

Here’s one thing we don’t know: Has Trump read the memo? I am willing to bet he has not.

The country has grown so accustomed to the mental limitations of its president that we have largely skipped over this question. And yet, the Department of Justice and the FBI believe there are profound national security implications in litigating its Russia counterintelligence operations in public. Numerous White House aides also believe they run a serious risk of throwing their weight behind a memo that may be a “dud.” The decision whether or not to publish it is, by everybody’s account, very serious. Yet nobody seems to be entertaining the question of whether the president has bothered to read the memo.

The Washington Post comes closest to addressing the mystery, yet fails to resolve the matter. The Post reports that the president “tuned in to cable television segments about the memo. He talked to friends and advisers about it.” He thereby “became absolutely convinced” it must be published. After becoming convinced, Trump “was then left alone to read the memo in its entirety.” And then Chief of Staff John Kelly “returned a few hours later and shared with the president his opinion.”

“A few hours” is obviously ample time to read a three-and-a-half-page memo. But the Post does not say that Trump read it, or even that he claimed to have read it. All we know is that he was left alone with a copy.

Could Trump have read the memo if he wanted to? Consider several accounts of the president’s extremely limited reading capacity:

—In 2016, Trump told Marc Fisher, he would like to read but, “I have so little time.” (The television isn’t going to watch itself.) He explained that reading is unnecessary to do his job anyway, because: “I’m a very efficient guy. Now, I could also do it verbally, which is fine. I’d always rather have — I want it short. There’s no reason to do hundreds of pages because I know exactly what it is.”

—In 2016, Tony Schwartz, the ghostwriter of Trump’s The Art of he Deal, told Jane Mayer, “It’s impossible to keep (Trump) focused on any topic, other than his own self-aggrandizement, for more than a few minutes.”

—Trump’s memos “preferably … must be no more than a single page. They must have bullet points but not more than nine per page,” a source told the Huffington Post.

—Conversations with some officials who have briefed Trump and others who are aware of how he absorbs information portray a president with a short attention span, Reuters has reported. “He likes single-page memos and visual aids like maps, charts, graphs and photos.”

—Analysts briefing Trump “should only include facts that support their analyses,” according to Mother Jones.

—The New York Times has reported that, “while Mr. Obama liked policy option papers that were three to six single-spaced pages, council staff members are now being told to keep papers to a single page, with lots of graphics and maps.”

—Trump himself told Axios last year, “I like bullets or I like as little as possible. I don’t need, you know, 200-page reports on something that can be handled on a page. That I can tell you.”

By the parameters of what Trump and his staff have reported about his reading ability, making it through a three-and-a-half-page memo appears to be wildly ambitious.

But this is a political debate about a document. What do we do when the decisive figure in such a debate is obviously incapable of making an informed judgment about the document in question?