This is the Thomas Jefferson Hour. Why are we talking about Theodore Roosevelt today?

Theodore Roosevelt was the 26th president of the United States. He took office 100 years after Thomas Jefferson became the third president. They are condemned to spend eternity on Mount Rushmore together. Right next to each other, in fact. There is no way that Jefferson could have admired the hectic, bombastic, extra-constitutional, war-loving Roosevelt, who was a self-professed Hamiltonian.

Jefferson was elegant, understated, and a small-r republican who wanted the United States to be a fourth- or fifth-rank country like China (then) or Canada (now). He envisioned a nation of highly educated family farmers.

Roosevelt dragged America, sometimes kicking and screaming, onto the world’s stage. He did not, like Jefferson, defer to the constitutional supremacy of the legislative branch. In fact, he once called the Senate a concatenation of shrill eunuchs.

Jefferson advocated strict construction of the Constitution, refusing even to create a national museum to house the Lewis and Clark artifacts without an enabling constitutional amendment. Jefferson argued that we must never do more than is specifically enumerated in the Constitution. Roosevelt scoffed at such a notion, said strict construction would have straitjacketed the United States into permanent imbecility both at home and abroad. Roosevelt argued that he could do anything not specifically prohibited by the Constitution. That would have given Jefferson one of his period migraine headaches.

Roosevelt didn’t really give a darn about family farmers, though he loved ranchers and especially cowboys, among whom he numbered himself after his adventures in Dakota Territory, my beloved North Dakota. In fact, TR said he would never have been president of the United States were it not for his time as a cowboy in the Dakota Badlands. One may question that lovely pronouncement — ambition finds a way — but North Dakotans love it, of course, which is one reason why we are building a TR presidential library in or near Medora, N.D., at the portal of Theodore Roosevelt National Park.

It’s hard to imagine Thomas Jefferson punching out a drunken gunslinger in a frontier saloon or galloping through a midnight thunderstorm to stop a stampede. He was too refined for such things, and even too frail. It’s equally hard to imagine Roosevelt building a domed Palladian villa for himself on Long Island or mastering ancient Greek for the purpose of reading Homer in the original.

Each of them was a great leader for his own time and place.

Not all leaders need to be the same. In fact, leaders who cling to outworn approaches, like Herbert Hoover or James Buchanan, wind up in the tipster of history. Jefferson wanted a small r republic. Roosevelt wanted a capital E empire. Jefferson said, “peace is my passion.” Roosevelt would have sneered at that. Jefferson’s annual messages to Congress were all under 1,000 words in length. Roosevelt’s first annual message to Congress, one of the longest in American history, took more than 2½ hours for the clerk to read to the stunned and glossy-eyed members of Congress.

What they shared beyond love of America and a special fascination with the American West was love of books. Jefferson wrote just one, “Notes on the State of Virginia,” and that somewhat reluctantly. Roosevelt wrote about 40, depending on how you count, some of them now regarded as American classics. Jefferson had a library of almost 7,000 volumes. Roosevelt read a book a day almost every day of his adult life.

Theodore Roosevelt may have been the best intellectually prepared president in American history, more even than the bookish and cerebral Jefferson; more than John Adams, who was a voracious, pugnacious and aggressive reader; more even than John Quincy Adams, who was brilliantly, obsessively educated. Jefferson read in seven languages, Roosevelt five. If they could ever have gotten over their profound differences of character and style, they would have had much to discuss.

Neither drank spirits — Roosevelt was a sarsaparilla man, Jefferson said he could not live without wine, but he never consumed it in excess.

So why did Roosevelt despise Thomas Jefferson? There are three reasons, I think. First, Jefferson was a strict constructionist and a minimalist with respect to government. That government is best which governs least. Roosevelt was a maximalist and a broad constructionist. Or to put it in a nutshell, Roosevelt was a Hamiltonian and Jefferson was, well, a Jeffersonian.

Second, Jefferson loved peace and believed that the United States should only engage in war if it were the very last melancholy response when every possible attempt at peaceful resolution had been tried, and then tried again, and that a nation should mourn when it had to take up arms against another sovereign nation. Roosevelt, to put it lightly, had no such misgivings. He won the Nobel Peace Prize — first president to earn it—and his seven years, 171 days were characterized by peace not war, but he earnestly believed that war is good for a country from time to time because it crushed the softness, what he called the effeminacy, out of a nation’s social fabric. He also believed that all great nations have been warring nations and, it simply has to be admitted, he thirsted for military glory. He loved war and knocked down a series of difficult hurtles to get himself to Cuba in 1898 so that he could experience what he called “my crowded hour.”

Roosevelt believed that Jefferson (and his lackey Madison) were pacifist ideologues who had made America vulnerable by reducing the size of the army and navy to nullities in the run-up to the War of 1812, which TR believed could have been avoided if we had armed ourselves properly, and would have gone much better, once underway, if we had prepared appropriately.

That, I think, was his principal disgust with Jefferson, and it came from the book he wrote, much it while a Harvard undergraduate, “The Naval War of 1812.” His research taught him that not only that Jefferson was a bubble-headed idealist who knew nothing about the way the world really operated but a kind of utopian visionary who preferred to live in a dream world rather than in the gritty arena that Hamilton saw (and experienced in the revolution). Hamilton called Jefferson “an intellectual voluptuary,” and that’s essentially how TR saw him, too.

Third, though he does not say it directly, I think Roosevelt regarded Thomas Jefferson as a coward. He was aware, of course, of Jefferson’s flight from Monticello in 1781 when the dashing British cavalier Banastre Tarleton’s dragoons rode up the mountain to arrest the governor in his Palladian mansion. That would not have set well with Roosevelt, who would have challenged Tarleton to a boxing match or a duel at 15 paces.

But TR also sensed that Jefferson’s soul was easily overwhelmed by conflict and tension, that Jefferson was always threatening to retire to Monticello — that he retired from the governorship after the Tarleton raid and said the criticism he received would stay with him until the all healing grave; that Jefferson retired from George Washington’s Cabinet in midterm when the daily conflict with the much more aggressive Hamilton offended his famous civility; and that Jefferson essentially abdicated the last year of his presidency when the Embargo Acts began to erode his enormous popularity with the American people.

You will remember that in 1910, at the Sorbonne, Roosevelt spoke his most famous words, his creed and motto: “It is not the critic who counts … the credit belongs to the man who is actually in the arena, whose face is marred with dust and sweat and blood.” Hard to imagine Jefferson’s face covered with blood. Even sweat seems a bit extreme for the Sage of Monticello.

I think Roosevelt’s fundamental argument with Jefferson was that when the crisis came — in 1776, in 1781, in 1793, in 1807, Jefferson not only didn’t thrust himself into the scrum at the heart of the arena, but he could be seen edging away to his fortress of solitude in the Blue Ridge Mountains, while composing love songs to “our own dear Monticello, where has Nature spread so rich a mantle under the eye.”

For Theodore Roosevelt, where the action was, there he gravitated, fists ready. For Thomas Jefferson, there was a fine glass of Bordeaux and a book of Greek verse waiting in his library at Monticello.

Take your pick. I love and admire Theodore Roosevelt, but I regard him as a dangerous man for a nation that seeks to remain a republic. I’m with Jefferson drifting along the Canal du Midi in southern France, writing exquisite letters to his family and friends, dreaming of utopia and trying to persuade his fellow Americans to aspire to be their best and most civilized selves.