Daniel Bell, a wide-ranging scholar and writer who coined the terms "post-industrial" and "the information society" and who predicted the collapse of communism, the rise of the Internet and other significant trends in economics and culture long before they occurred, died Jan. 25 at his home in Cambridge, Mass. He was 91. The cause of death was not disclosed.

Dr. Bell trained as a sociologist and was a professor at Columbia and Harvard universities. He was among the country's first "public intellectuals," whose impact reached far beyond academia. His portfolio roamed freely across many fields, including politics, economics, history, education, cultural studies and religion.

As early as 1967, when home computers were mere fantasies, Dr. Bell had foreseen the rise of the Internet. He imagined "tens of thousands of terminals in homes and offices 'hooked' into giant central computers providing library and information services, retail ordering and billing services, and the like."

In one of his most influential books, 1973's "The Coming of Post-Industrial Society," Dr. Bell said the computer would come to define the late 20th century as much as the automobile had the first half of the century.

He foretold "the pre-eminence of the professional and technical class" and growing global economic competition as manufacturing gave way to an international economy built on technology and services. With less emphasis on manual labor, Dr. Bell added, it was only a matter of time before communism and other Marxist ideologies fell under their own weight.

Two of his other books, "The End of Ideology" (1960) and "Cultural Contradictions of Capitalism" (1978), were cited by the Times Literary Supplement, a British publication, as among the 100 most influential books written since World War II.

In the latter book, Dr. Bell argued that the self-indulgent societies created by free markets and easy credit undercut the capitalist system itself and its purported values of discipline and restraint.

"Hedonism has replaced the old bourgeois value of delayed gratification," he said in 1989.

In "The End of Ideology," Dr. Bell suggested that political systems based on fixed intellectual notions - Marxism, in particular - were fading in importance and would be replaced by more pragmatic forms of belief.

"A utopia has to specify where one wants to go, how to get there, the costs of the enterprise, and some realization of and justification for the determination of who is to pay," he wrote.

In 1999, the Economist magazine named Dr. Bell "America's most eminent post-war social theorist," but for all his pronouncements on social trends and public policy, his personal views were hard to pin down.

At 13, he had given speeches in support of socialist presidential candidate Norman Thomas. But in his first book, "Marxian Socialism in the United States" (1952), he argued that the views of socialists were simply too rigid to gain a large following in freewheeling America.

Dr. Bell stayed away from partisan politics and, despite his Jewish heritage, he professed no particular religious views. He opposed the Vietnam War but also detested the 1960s counterculture, which he considered selfish, totalitarian and intellectually empty - built on "the shambles and appetite of self-interest," as he put it.

Instead of being the champion of social trends, he contented himself with examining them. He described himself, seemingly without contradiction, as "a socialist in economics, a liberal in politics and a conservative in culture."

He was born Daniel Bolotsky on Manhattan's Lower East Side on May 10, 1919. His parents were immigrants from Eastern Europe, and he was an infant when his father died.

He spoke Yiddish while growing up and, at his bar mitzvah, told his rabbi that he didn't believe in God.

"Tell me," he said the rabbi replied, "do you think God cares?"

He was 13 when his family changed its name to Bell, and at 16 he entered City College of New York. In the 1930s, CCNY was known for its young, mostly Jewish students, later collectively called the "New York intellectuals," who spent hours debating literature, society and Marxism.

Mr. Bell's classmates included such future intellectual stars as writers Irving Kristol and Irving Howe, sociologists Nathan Glazer and Seymour Martin Lipset and art critic Harold Rosenberg. The intellectual ferment of the time was depicted in a 1998 documentary, "Arguing the World."

After graduating from CCNY, Dr. Bell worked at the New Leader magazine and then taught at the University of Chicago. He spent many years as the labor editor of Fortune magazine while writing some of his first books and articles.

He received a doctorate in sociology from Columbia in 1959 and taught at the university until 1969, when he moved to Harvard.

In 1965, he and Kristol founded the Public Interest, a journal designed, as Dr. Bell later wrote, "to transcend ideology through reasoned public debate."

Dr. Bell broke with Kristol in the 1970s over Kristol's increasingly conservative political leanings. The Public Interest later became a seminal publication of the neo-conservative movement.

His first two marriages, to Nora Potashnick and Elaine Graham, ended in divorce.

Survivors include his third wife, Pearl Kazin Bell, the sister of literary critic Alfred Kazin; a daughter from his first marriage; a son from his third marriage; and four grandchildren.

Dr. Bell continued to write books and publish new editions of his earlier ones. His intellectual grasp was so wide it was sometimes hard to tell what his primary field of study was. Once, when he was a graduate student, he was asked his specialty.

"I specialize in generalizations," he said.