John R. Silber, president of Boston University for 25 years who set a hard-nosed example of how to elevate a second-tier school in a hurry and lost a close election for Massachusetts governor running as a maverick Democrat, died Sept. 27 at his home in Brookline, Mass. He was 86.

The university said the cause of death was kidney failure.

A champion of high academic standards and scholar of the 18th-century philosopher Immanuel Kant, Dr. Silber was Boston University’s president from 1971 to 1996 and then its chancellor until 2003. In that span, the university morphed from a lightly regarded commuter school, in the shadow of Harvard University and the Massachusetts Institute of Technology, to a major research institution in its own right.

“He was notoriously difficult and prickly and outspoken,” said Terry W. Hartle, senior vice president of the American Council on Education, which represents more than 1,600 college and university presidents. “But his legacy was an extraordinary institution that wasn’t there before.” Hartle called Dr. Silber “one of the best-known and most visible college presidents of the last 50 years.”

Over his decades in public life, Dr. Silber dominated university politics — often crushing dissenters — and then waded into politics with a blunt tongue that drew national attention.

Democratic Massachusetts gubernatorial candidate John R. Silber, left, shares a laugh with Sen. Edward M. Kennedy, (D-Mass.) in 1990. He narrowly lost the election. Known for his autocratic style, Dr. Silber was the longtime president of Boston University. (Associated Press)

In his 1990 campaign for governor, Dr. Silber suggested that liberal social policies had turned Massachusetts into a “welfare magnet” for “people who are accustomed to living in the tropical climate.” He also questioned the use of costly medical interventions for elderly people about to die. “When you’ve had a long life and you’re ripe, then it’s time to go,” he said.

His message, questioning what he called the party’s “social engineers,” helped him win an upset victory that year in the Democratic primary. But Dr. Silber narrowly lost to Republican William Weld, a former federal prosecutor. Analysts said a possible factor was Dr. Silber’s outburst at a popular television interviewer when she asked him about his faults shortly before the election. In academia, Dr. Silber was no less confrontational.

Dr. Silber stared down 10 deans and three-quarters of the faculty assembly in 1976 who called for his resignation because they were unhappy with his autocratic style. The university’s board of trustees stood by him.

During the Vietnam War, Dr. Silber called in police to break up student protests over military recruiting. He also weathered a faculty strike and clashes with staff over budget cuts and personnel policies.

“You know the expression ‘you can’t make an omelet without breaking an egg’?” said Stephen J. Trachtenberg, the former president of George Washington University who served as an administrator under Dr. Silber in Boston in the 1970s. “John Silber made a two-egg omelet breaking 20 eggs. He was a change agent of the most dramatic sort. Very in-your-face.”

Trachtenberg recalled one meeting in which Dr. Silber belittled a university dean in front of peers. Dr. Silber, Trachtenberg said, had a yen “to be the smartest man in the room,” sometimes to a fault.

Under Dr. Silber, the university’s endowment was reported to have grown from $18 million to $422 million. There was also a boom in its physical facilities and research funding. For many years, he was one of the highest-paid university presidents.

Dr. Silber recruited to the faculty such luminaries as writers Elie Wiesel, Derek Walcott and Saul Bellow.

Wiesel said Thursday that Dr. Silber pursued him for a year before he accepted the invitation. “He was obstinate,” Wiesel said. “Once he had an idea, he had to bring it to fruition.” Dr. Silber’s pitch, Wiesel recalled: “I want to make [Boston University] one of the best. Come and help me.”

But Howard Zinn, a political science professor at the university, once told the Boston Globe: “For every important person Silber has brought here, a greater number of people have been refused tenure or left in disgust.”

Time magazine described Dr. Silber in 1989 as “The Ivory Tower Triggerman” and quoted him as critiquing the education system in a memoir he titled “Straight Shooting.”

“The standards today are derisory by standards that were operative in ordinary little country schools a hundred years ago,” he wrote.

Dr. Silber, in the magazine’s account, lamented that the goal of equal opportunity was too often confused with a mistaken belief in equal ability. “Not a single member of our founding fathers believed any such rubbish,” Dr. Silber wrote. “It is perfectly obvious that all individuals are not born with equal ability. I wish I could run as fast as Carl Lewis. I can’t.”

John Robert Silber was born on Aug. 15, 1926, in San Antonio with a right arm that ended about where an elbow would normally be. He said the stub was “very sensitive” and that his mother cut off the sleeves from his coat and shirt so he could use it.

He received a bachelor’s degree in 1947 from Trinity University in San Antonio and a doctorate in philosophy from Yale University in 1956. He spent much of his early academic career at the University of Texas at Austin.

He married Kathryn Underwood in 1947, and she died in 2005. Survivors include seven children; a brother; 26 grandchildren; and three great-grandchildren. A son died of AIDS in 1994.

Boston University remains highly regarded. U.S. News & World Report, a leading arbiter of prestige, ranks it 51st among national universities, tied with George Washington and Tulane universities.

In 2007, Dr. Silber said of his tenure: “BU was one of the finest toys I was ever allowed to play with — a great toy with enormous potential, if you polished it up and gave it a few tools to make it run.”