UNDER ITS first editor, Herbert Croly, The New Republic was the preeminent intellectual voice in the years before and during America's participation in World War I. In 1918, 45,000 people subscribed to the self-proclaimed "mouthpiece" of the elite. Oswald Garrison Villard, editor of the rival Nation, noted that "it was considered bad form in some official circles to be seen without it." President Woodrow Wilson quoted its editorials and incorporated its ideas into his wartime policies and goals. Walter Lippmann, one of The New Republic's first senior editors thought the "journal of opinion" could even move the stock market.

Although until now here has been no biography of Herbert Croly, it was not because his influence and importance were unknown. Indeed, his book, The Promise of American Life, published in 1909, earned its author the deserved reputation for being the United States' most thoughtful political theorist in the 20th century.

When Herbert Croly was born in 1869, he was "christened" into August Comte's Religion of Humanity. His parents, both journalists, had been impressed by the French philosopher's guiding principle that life's goal was to advance the welfare of mankind. As David Levy's Herbert Croly of 'The New Republic' persuasively shows, it was a lesson Croly never forgot. Although he later rejected many of Comte's ideas, Croly absorbed, updated and Americanized Comte's belief that only a strong central government could unite a nation's disparate groups in the interest of national development and social progress.

Croly based The Promise of American Life on the not unrealistic observation that at the beginning of this century the United States was a nation perilously divided by class, race, religion and region. Moreover, under pressure of industrialization, the growth of cities, and unprecedented immigration, American society was becoming increasingly fragmented and disoriented. Croly placed much of the blame for his society's confusion squarely on America's Jeffersonian heritage -- in particular, its firm commitments to minimal government, decentralized authority and the sanctity of individual freedom. These outdated principles, he said, left the United States unequipped to deal with the exigencies of an industrial age. Calling himself a neo-Hamiltonian, Croly argued that the United States needed a strong central government which, under the direction of a public-spirited, disinterested elite, could restore America's democratic national purpose.

Croly's "New Nationalism," which emphasized the regulation of big business rather than its dismemberment, appealed to many readers. One was Willard Straight, a wealthy industrialist with imperialist ambitions. Straight and his wife, Dorothy, heiress to the Whitney fortune, in fact were so impressed by The Promise of American Life that they decided to launch The New Republic with Croly as its editor-in-chief.

LIKE FUTURE editors of The New Republic, Croly regretted the United States' reluctance to become involved in world affairs. With his colleagues Walter Lippmann and Walter Weyl, he thought it fortuitous therefore that the emergence of The New Republic at the end of 1914 coincided with the start of a world war. The centralizing demands of modern warfare, they believed, would challenge "conventional ways of looking at things," and so make American society more receptive to reform. Croly became a leading advocate of military preparedness, and, after the United States entered the European conflict in 1917, regarded the war generally as a "rare opportunity " to reorder the chaos in both American and international affairs.

Croly was not alone in believing the war would help advance his liberal ideology. Indeed, because Randolph Bourne's dissent was so rare, it was all the more remarkable that this former New Republic essayist saw so clearly how unrealistic were Herbert Croly and his fellow progessives' dreams of war-inspired social progress. Where Croly thought that cool-headed, pragmatic intellectuals like himself could channel the nation's energies unleashed by the war in progressive directions, Bourne recognized that the real enemy was war itself. "Only in a world where irony was dead," he wrote, "could an intellectual class enter war . . . in the avowed cause of world liberalism and world democracy."

Bourne's criticism of Croly's ideology still applies to the liberals' dilemma today. The progressives, Bourne believed, failed to define adequately their ultimate goals. They were too concerned with technique, new ideas and power, and consequently forgot what they stood for. "They have, in short, no clear philosophy of life except that of intelligent service," he wrote. "They are vague as to what kind of society they want, or what kind of society America needs, but they are equipped with all the administrative attitudes and talents to attain it."

By 1919 Croly knew Bourne had been correct. The Treaty of Versailles represented a harsh and punitive peace, and in opposing it, Croly acknowledged that his hopes had been misplaced. Cut off from his former access to power, he spent his last decade believing, particularly as he surveyed the widespread repression in the United States during the 1920s, that his life had been a failure.

David Levy disagrees. In the conclusion to Herbert Croly of 'The New Republic', he notes that the '20s were an aberration in an otherwise long history of the "steady nationalization of American life," and that, had he not died in 1930, in the second Roosevelt era Croly would have recognized policies that owed much to his faith in the power of government to improve the conditions of the country.

It is hard to disagree. From 1932 until 1980, Croly's belief that government must consciously promote social welfare provided the intellectual backbone for the policies of every administration, both Democratic and Republican. Ronald Reagan's government is an exception. Unlike Croly, President Reagan believes that individual and collective interests are synonymous, and as he has repeated many times, his administration is trying to reverse the flow of history by diminishing the powers and responsibilities of the federal government.

This is an important development, and it indicates the continuing appeal of the Jeffersonian image in the American mind. Levy does not mention this. In fact, he seldom discusses the significance of Croly's thought; rather, his is a masterful explication of the origins and development of Croly's ideas, but his treatment leaves the reader wishing the author had evaluated more fully Herbert Croly's place in history. In addition, the book bears many of the unfortunate hallmarks of modern scholarship. Although it is based upon years of prodigious research, it also has a stiff list price, tiny print, thick footnotes, and, as noted, conclusions which do not challenge. In short, Levy is a marvelous guide through the woods, but seldom does he give the reader an aerial view of the forest, or what the larger significance of Herbert Croly's life and thought is and might be.