ST. PAUL, Minn. -- The word "experience" appears 91 times in the Federalist Papers, those distillations of conservative sense and sensibility. Madison, Hamilton and Jay said that truths are "taught" and "corroborated" by experience. These writers were eager to "consult" and be "led" by experience. They spoke of "indubitable" and "unequivocal" lessons from experience, the "testimony" of experience and "the accumulated experience of ages." "Accumulating" experience is "the parent of wisdom" and a "guide" that "justifies," "confirms" and can "admonish." America's Founders were empiricists and students of history who trusted "that best oracle of wisdom, experience," which is humanity's "least fallible guide."

A telling touch, that "least fallible." The Founders represented the sober side of the Enlightenment. They knew, as conservatives do, that all guides are fallible. Hence conservatism's inclination to discern prescriptions in traditions, which are mankind's slow adjustments to the accretion of experiences.

So, Sarah Palin. The man who would be the oldest to embark on a first presidential term has chosen as his possible successor a person of negligible experience.

Any cook can run the state, said Lenin, who was wrong about that, too. America's gentle populists and other sentimental egalitarians postulate that wisdom is easily acquired and hence broadly diffused, therefore anyone with a good heart can deliver good government, which is whatever the public desires. "The people of Nebraska," said the archetypal populist William Jennings Bryan, "are for free silver and I am for free silver. I will look up the arguments later."

John McCain's opponent is by far the least experienced person to receive a presidential nomination in the 75 years since the federal government became a comprehensively intrusive regulatory state and modern weaponry annihilated the protection the nation derived from time and distance. Which is why McCain's case for his candidacy could, until last Friday, be distilled into two words: Experience matters.

McCain, who at 72 is 22 years older than Alaskan statehood, is 27 years and six months older than his running mate, who was 8 when Joe Biden was elected to the Senate. But in 1856, James Buchanan, 65, was 29 years and eight months older than his running mate, John Breckinridge, who was 35. Buchanan could run with that stripling because Buchanan was the most qualified person to run for president, before or since.

At least he was if varied experience in high offices fully defines who is "qualified." But it does not.

Buchanan had been a five-term congressman, then ambassador to Russia, then a two-term senator, then secretary of state, then ambassador to Britain. Buchanan then became perhaps the worst president.

Clearly, experience is not sufficient to prove a person "qualified" for the presidency. But it is a necessary component of qualification.

So are two other attributes. One is character. Richard Nixon was qualified by his experience as congressman, senator and vice president, but disqualified by character. The second is a braided mental rope of constitutional sense and political common sense.

In his Denver speech, Barack Obama derided the "discredited Republican philosophy" that he caricatured in four words -- "you're on your own." Then he promised to "keep ... our toys safe." Among the four candidates for national office, perhaps only Palin might give a Madisonian answer -- one cognizant of the idea that the federal government's powers are limited because they are enumerated -- if asked to identify any provision of the Constitution, other than the First Amendment, that imposes meaningful limits on congressional or executive authority to act.

If so, she would be a good influence on Washington, including McCain. But is there any evidence that she has thought about such matters? McCain's selection of her is applied McCainism -- a visceral judgment by one who is confidently righteous. But the viscera are not the seat of wisdom.

In 1912, McCain's Arizona became the 48th state. In 1959, Palin's Alaska became the 49th. Western conservatism has the libertarian cast of a region still steeped in an individualism natural to the frontier's spaciousness. But American conservatism depends on what it calls "fusion," the collaboration of libertarians and social conservatives concerned that liberty unleavened by restraints creates a licentious culture. Palin supposedly is fusion in one person.

Many cultural conservatives, who are much of the GOP's base, consider McCain's adherence to their persuasion perfunctory. By his selection of Palin, he got the enthusiasm of the base. But what has he got in Palin? In coming days he and we will learn from a stern teacher, experience.