"Genius"is an ambiguous, if not a deceptive, term. We apply it, quite rightly, to a Newton, a Mozart, a Heisenberg, a Yehudi Menuhin, to explain what is otherwise inexplicable, to suggest that, somehow, the lightning strikes, or the Holy Ghost descends. Thomas Jefferson was probably closer to genius than any other public figure in our history, but there is nothing of the mystical in his own notion of genius, which in his mind was expressed in "virtue" and in the "passion to guard the sacred rights and liberties of men."

Musical and mathematical genius is almost inexplicable, but what we call political genius is a very different matter. It is far easier to recognize, and we have applied the term almost indiscriminately to Washington, Jefferson, Hamilton, Lincoln and Franklin Roosevelt. Often it is applied not to an individual but to a whole society: thus we speak of the Greek genius for political philosophy, the Roman genius for empire, the English genius for law, and thus, too, the genius of the American founding fathers for politics and government.

In Paris in 1787, Jefferson followed with close attention the proceedings of the Philadelphia Constitutional Convention; writing to his old friend John Adams he said that "it is really an assembly of demigods." By any political standards it was indeed.

How did it happen that a new nation, with a white population smaller than that of Philadelphia today, with no city as large as Alexandria, lacking in most of the institutions of organized society -- universities, libraries, museums, an aristocracy, an established church, military -- could produce in one long generation Franklin and Washington, Jefferson and John Adams, Hamilton and Gallatin, James Wilson and John Jay, James Madison and John Marshall and Tom Paine, who was far more an American than an English product?

How did it happen that a printer's apprentice from Boston, Benjamin Franklin, with no formal education, was the ideal and the symbol of the Englishment everywhere, the Solon of modern times? How did it happen that a Virginia planter without any formal education should emerge to help create and then preside over a new nation, guide its destinies to happiness and prosperity, and be revered like no other man of his time, in the Old World and the New, as a symbol of nobility and virtue? How did it happen that another Virginia planter, who grew up on the frontier with none of the advantages of the European philosophes, should overshadow even Voltaire and Goethe as the most distinguished statesman-philosopher-scholar-artist-moralist of the Western world? And how did it happen that all of these men and countless others chose to devote their lives, and their fortunes, to the public service?

How did it happen that a relatively unsophisticated people in the rural Republic were wise enough to find and elect Washington, John Adams, Jefferson, Madison, Monroe and John Quincy Adams to the presidency, while the sophisticated and universally literate millions of our time chose the mixed and unimpressive bag of Kennedy, Johnson, Nixon, Ford, Carter and Reagan?

How did it happen that two young men in their 30s (with the occasional assistance of an old man in his early 40s!) were able to dash off, in the midst of exacting political duties, 85 Federalist Papers, probably the greatest political treatise since Montesquieu, while the thousands of highly trained scholars at two-score advanced institutes of government today have produced nothing comparable?

How did it happen that every major political and constitutional institution which we now have was invented before the year 1800, and that not one of comparable importance has been invented since?

That question suggests the beginning of an explanation -- or anyway of illumination.

"New occasions teach new duties," Lowell wrote in The Present Crisis. Independence was indeed a new occasion, and imperatively required solutions. As Franklin put it, "We shall all have to hang together or we shall hang separately." The "solutions" which Americans discovered represent the greatest upsurge of political inventiveness in modern history.

Americans "brought forth a new nation," the first "created" by people, and equipped it with a written Constitution, another first. They devised a federal system that worked, abolished colonies by making them commonwealths, soothed religious antipathy through separating church and state, adopted "bills of rights" and empowered the courts to enforce them, and put civilians in charge of the military. They proclaimed the principle of equality -- alas, for whites alone -- and through an immigration system of astonishing liberality built the closest thing to a classless society the world had then seen. They achieved the highest literacy rate in the 18th century world (again, among whites) and sought in vain through isolationism to separate themselves from European conflicts.

How explain this explosion of collective political genius?

First, a very practical explanation. In the simple agrarian society of the 18th century there were few other outlets for talent than public service. Moreover, such education and training as young men had (women were not much exposed to either) tended to exalt public careers. Schools and colleges inculcated morality, public and private alike, philosophy and the classics. Most American statesmen had been exposed to Thucydides and Plutarch and Cicero. Their political vocabulary was Latin: republic, federalism, legislature, judiciary, president, congress, capitol. The authors of The Federalist Papers signed themselves Publius, while the officers of the Revolutionary army established the Society of the Cincinnati. As the famous preacher-patriarch Jonathan Mayhew wrote, "Having been initiated in youth in the doctrines of civil liberty as they are taught by Plato, Demosthenes, Cicero and such as Sidney, Milton and Locke among the moderns, I liked them, they seemed rational. They hearkened to Washington's admonitions that there is 'an indissoluble union between virtue and happiness, between beauty and advantage, between an honest and magnanimous policy and the solid rewards of public felicity.' And many of them agreed with Dr. Rush, one of the signers, that every man in a republic is public property. His time and talents, his youth and manhood and his old age all belong to his country."

There was also a practical consideration. It did not cost anything to run for office and therefore talented young men without money (few had any money) could afford to go into politics. The corollary, however, was discouraging: political and judicial offices were so poorly paid that many men could not afford to stay in the public service. It is sobering to recall that Washington had to borrow $100 to go to his own inauguration, and that friends had to educate Hamilton's children and that Jefferson died a bankrupt, Monticello sold to pay his debts. What all this meant was that "fame is the spur" -- fame and the happiness of posterity.

That is the final consideration, one that has all but disappeared. Washington invoked Posterity in all of his public addresses; John Adams wrote it into the Constitution of Massachusetts five times; Tom Paine reasxsured the veterans of Valley Forge, "This not the concern of a day or a year or an age; posterity are involved in the contest." Or listen to John Adams' letter to his wife Abigail after he had signed the Declaration: "Through all the Gloom, I can see the rays of ravishing light and glory; posterity will triumph, even though we should rue it."

The contrast of all this with our own day is clear, and throws some light on the evaporation of "genius" in American politics. For our generation is committed to private and not public enterprise, to individual fulfillment and not to the general welfare -- a phrase that the founding fathers wrote twice in the Constitution of the United States. But who now, even in the most exalted offices, appeals to Virtue and Posterity? Who now invokes that tribute of Pericles to his beloved Athens, whose citizens, he said, "draw strength from the busy spectacle of our great city's life as we see it before us, falling in love with her as we see her day by day, and remembering that all this greatness she owes to men with the fighter's daring, the wise man's understanding of his duty and the good man's self-discipline in its performance, men who knew that the secret of happiness is freedom, and the secret of freedom a brave heart, and who did not stand aloof from the onset of the enemy"?