Literary travels: following Tocqueville; American Journey: Traveling with Tocqueville in Search of America, by Richard Reeves. New York: Simon & Schuster. 399 pp. $15.95.

A hundred and fifty years ago, the French aristocrat Alexis de Tocqueville made a nine-month tour of the United States, ostensibly to investigate the penal system here. Returning home, he wrote his two-volume classic, ''Democracy in America,'' pronouncing the new method of governance in the infant nation flawed but flourishing.

Seeking to test whether yesterday's verities are today's truths, political reporter Richard Reeves set out from Newport, R.I., in 1979, as Tocqueville had done in 1831, intending to retrace the Frenchman's steps. Along the way, he sought out people of similar station to those the man he calls his ''incomparable guide'' had met and interviewed -- e.g., President-in-exile Richard Nixon for the recently rejected President John Quincy Adams; current Harvard president Derek Bok for the Jacksonian era Harvard president, Josiah Quincy Jr.; as well as scores of anonymous members of all races and classes.

At its best, the method produces a host of provocative ideas. For example, back in 1831 Gov. Enos T. Throop of New York had postulated that most politicians were men ''whose capacity and character place them in the second rank.'' The brilliance and dedication of the Founding Fathers had passed into the realm of American mythology. Money and power were the new gods attracting the energies of distinguished men.

To explore the situation as it exists today, Reeves spoke to Hugh Carey, the current governor of New York. He agreed with his predecessor, adding: ''Young lawyers, young doctors, young financiers, young planners, young engineers and environmentalists . . . they all are more impressive than the people I see in politics and government anymore.'' And in Cambridge, a Harvard professor of government, Stanley Hoffman, appraised students planning to go into government as ''unbelievably mediocre people.''

Another subject arising from Tocqueville's study is America's much-touted litigiousness. Tocqueville thought the explanation might be repeated uprootings, first from the Old World to the New, then from the settled East to the frontier West, so that over and over again comfortable old customs and traditions had to be cast aside for strange new laws and institutions. Speaking to Reeves on the subject, Potter Stewart, the former Supreme Court justice, Laurence Tribe, a Harvard law professor, and J. Vincent Aug, United States magistrate for the Sixth Circuit, all agreed that because the executive and legislative branches of government failed to resolve questions involving politics, economics, and morality, the courts had to take over.

On the question of women's rights, the ever-prescient Tocqueville had written that democracy might ''ultimately come to change the great inequality between man and woman which has up till now seemed based on the eternal foundations of nature.'' So Reeves questioned Betty Friedan, founding mother of the National Organization for Women, who assured him it was no accident that the modern women's movement started in America.

And now, Reeves discovered, women vote differently from men on both candidates and issues. Furthermore, women oppose war and militarism in significantly higher numbers than men. Women are ''closer to life,'' Friedan said; ''more inclined to mistrust violence,'' declared Gloria Steinem, editor of the feminist magazine Ms.

Americans are bound to finish this book with hope for themselves and the nation. Tocqueville, writing in an era of prodigious growth, could only marvel at the repeatedly expressed confidence that Americans ''form a species apart from the rest of the human race.'' Reeves, in more than a hundred conversations -- in a year of national contraction politically, economically, and internationally -- heard America described as the ''best'' and ''wonderful.''

As for Reeves himself, he should be spanked for his occasional indulgence in pontification about the obvious. But when he sticks to his original scheme, he too deserves rave notices.