They don't hold White House lunches the way they used to at the beginning of the century. On Jan. 1, 1907, for example, the guest list was as follows: a Nobel prizewinner, a naval historian, a biographer, an essayist, a paleontologist, a taxidermist, an ornithologist, a field naturalist, a conservationist, a big-game hunter, an editor, a critic, a ranchman, an orator, a country squire, a civil service reformer, a socialite, a patron of the arts, a colonel of the cavalry, a former Governor of New York, the ranking expert on big-game mammals in North America and the President of the U.S.

All these men were named Theodore Roosevelt.

In his protean variety, his febrile energy (which could have come from his lifelong habit of popping nitroglycerin pills for a dicey heart), his incessant self-celebration and his absolute refusal to believe there was anything finer than to be born an American, unless to die as one in some glorious battle for the flag, the great "Teddy" was as representative of 20th century dynamism as Abraham Lincoln had been of 19th century union and George Washington of 18th century independence.

Peevish Henry Adams, who lived across the square from the White House and was always dreading that the President might stomp over for breakfast (T.R. thought nothing of guzzling 12 eggs at a sitting), tried to formulate the dynamic theory of history that would explain, at least to Adams' comfort, why America was accelerating into the future at such a frightening rate. His theory was eventually published in The Education of Henry Adams but makes less sense today than his brilliant description of the President as perhaps the fundamental motive force of our age: "Power when wielded by abnormal energy is the most serious of facts ... Roosevelt, more than any other man living within the range of notoriety, showed the singular primitive quality that belongs to ultimate matter."

In his youth, as indeed during his infamous "White House walks," which usually culminated in a nude swim across the Potomac, Theodore Roosevelt's cross-country motto was "Over, Under or Through — But Never Around." That overmastering directness and focus upon his objective was the force that Adams identified. But T.R., unlike so many other active Presidents, also had a highly sophisticated, tactical mind. William Allen White said that Roosevelt "thought with his hips" — an apercu might better be applied to Ronald Reagan, whose intelligence was intuitive, and even to Franklin Roosevelt, who never approached "Cousin Theodore" in smarts. White probably meant that T.R.'s mind moved so fast as to fuse thought and action.

He was, after all, capable of reading one to three books daily while pouring out an estimated 150,000 letters and conducting the business of the presidency efficiently so he could usually spend the entire afternoon goofing off, if his kind of mad exercise can be euphemized as goofing off. "Theodore!" Senator Henry Cabot Lodge was once heard shouting, "if you knew how ridiculous you look up that tree, you'd come down at once!"

The obvious example of T.R.'s "Never Around" approach to statesmanship was the Panama Canal, which he ordered built in 1903, after what he called "three centuries of conversation." If a convenient revolution had to be fomented in Colombia (in order to facilitate the independence of Panama province and allow construction to proceed p.d.q.), well, that was Bogota's bad luck for being obstructionist and good fortune for the rest of world commerce. Being a historian, T.R. never tired of pointing out that his Panamanian revolution had been only the 53rd anti-Colombian insurrection in as many years, but he was less successful in arguing that it was accomplished within the bounds of international law.

"Oh, Mr. President," his Attorney General Philander Knox sighed, "do not let so great an achievement suffer from any taint of legality." Dubious or not as a triumph of foreign policy, the canal has functioned perfectly for most of the century, although its control has reverted to the country.

But T.R. deserves to be remembered more for some acts than land grabbing south of the border. He fathered the modern American Navy, for example, while his peacemaking between Russia and Japan in 1905 elevated him to the front rank of presidential diplomats. He pushed through the Pure Food and Meat Inspection laws of 1906, forcing Congress to acknowledge its responsibility as consumer protector.

Many other Rooseveltian acts loom larger in historical retrospect than they did at the time, when they passed unnoticed or unappreciated. For example, T.R. was the first President to realize that this nation's future trade posture must be toward Asia and away from the Old World entanglements of its past. Crossing the Sierra Nevada on May 7, 1903, he was surprised at the beauty and otherworldliness of California. New York — his birthplace — seemed impossibly far away, Europe antipodean. "I felt as if I was seeing Provence in the making." There was no doubt at all in T.R.'s leaping mind which would be the world's next superpower. Less than five years before, he had stormed San Juan Heights in Cuba and felt what he described as the "wolf rising in the heart" — that chief lust for victory and power that drives all conquerors. "Our place ... is and must be with the nations that have left indelibly their impress on the centuries!" he shouted in San Francisco.

It's tempting to speculate how T.R. might behave as President if he were alive today. The honest answer, of course, is that he would be bewildered by the strangeness of everything, as people blind from birth are said to be when shocked by the "gift" of sight. But he certainly would be appalled by contemporary Americans' vulgarity and sentimentality, particularly the way we celebrate nonentities. Also by our lack of respect for officeholders and teachers, lack of concern for unborn children, excessive wealth and deteriorating standards of physical fitness.

Abroad he would admire our willingness to challenge foreign despots and praise the generosity with which we finance the development of less-fortunate economies. At home he would want to do something about Microsoft, since he had been passionate about monopoly from the moment he entered politics. Although no single trust a hundred years ago approached Mr. Gates' empire, the Northern Securities merger of 1901 created the greatest transport combine in the world, controlling commerce from Chicago to China.

T.R. made it unsuccessful. In doing so he became the champion of American individual enterprise against corporate great health. That reputation suited him just fine, although he personally believed in Big Business and worried about competition which was imperfect and out of control. All he wanted to establish, early in his first term, was government's right to regulate rampant entrepreneurship.

Most of all, I think, Theodore Roosevelt would use the power of the White House in 1998 to protect our environment. His earliest surviving letter, written at age 10, mourns the cutting down of a tree, and he went on to become America's first conservationist President, responsible for five new national parks, 18 national monuments and untold millions of acres of national forest. Without a doubt, he would react toward the great swaths of farmland that are now being carbuncled over with "development" as he did when told that no law allowed him to set aside a Florida nature preserve at will.

"Is there any law that prevents me declaring Pelican Island a National Bird Sanctuary?" T.R. asked, not waiting long for an answer. "Very well, then," reaching for his pen, "I do declare it."