JERUSALEM, March 10 — When Mahmoud Abbas wanted to deliver his harsh critique of the current Palestinian uprising, he did so in his typically low-key way.
In October, Mr. Abbas, who was selected last week by Yasir Arafat to become the first Palestinian prime minister, had his office leak a speech from a closed-door meeting. In it, he said taking up arms against Israel was a mistake that had cost the Palestinians dearly.
"Many people diverted the uprising from its natural path and embarked on a path we can't handle, with the use of weapons," Mr. Abbas said in the speech to the Fatah movement, the group he helped Mr. Arafat, the Palestinian leader, establish in 1965. "What happened in these two years, as we see it now, is a complete destruction of everything we built."
The episode reflected much about the character of Mr. Abbas, who is widely known as Abu Mazen: his pragmatic position on the Middle East conflict, his discreet style, and his willingness to voice opinions that run counter to prevailing sentiment on the Palestinian street.
With the United States and others pressing the Palestinians for political reform, the Palestinian legislature voted overwhelmingly today to approve the creation of the prime minister's position and was expected to approve Mr. Abbas's nomination soon.
Mr. Abbas, 67, was on the White House lawn when Israel and the Palestinians signed a breakthrough agreement in 1993 and was at the table during the seven years of negotiations that followed.
Yet he has always shunned the limelight, rarely making speeches or granting interviews. He has been an influential Palestinian figure for decades, though younger and more radical Palestinians view him as too willing to compromise with the Israelis. He has virtually no following among the Palestinian public, but is well respected among diplomats.
"He's a very private person who comes across as aloof," said Ali Jerbawi, a political science professor at Bir Zeit University in Ramallah. "He likes to think things over. He reads a lot. He dares to give his opinion even if it goes against the general atmosphere."
While Mr. Abbas is very much part of Mr. Arafat's old guard, he has a temperament that is the polar opposite of that of Mr. Arafat, who enjoys the spotlight, plays to the audience and rarely misses an opportunity to make dramatic gestures.
Their relations have sometimes been rocky, with arguments that resulted in extended periods in which they did not speak to each other.
"They have differences, but they also have a bond that goes back a long way, and perhaps they complement each other," Mr. Jerbawi said.
Israel's prime minister, Ariel Sharon, says no peace deal is possible with Mr. Arafat and has refused to deal with him. With the United States also boycotting Mr. Arafat, the appointment of Mr. Abbas could open a new channel for dialogue, even if the prospect of full-scale negotiations remains dim.
But, Mr. Abbas has said that he does not believe that Mr. Sharon is serious about a peace deal and that his unwillingness to negotiate would be clear if the Palestinians called off the armed struggle and pressed for a resumption of peace talks.
Israeli leaders know Mr. Abbas well from the years of negotiations, and have been supportive of his appointment, though they are skeptical about how much authority Mr. Arafat will grant him.
"If it becomes evident that the prime minister appointed by the Palestinians has powers and takes actions to end terror and it isn't just another trick by Arafat, this could be the beginning of a change," Israel's defense minister, Shaul Mofaz, told the daily Maariv.
In much of the Arab world, leaders rarely share much authority. Mr. Arafat, the pre-eminent Palestinian leader for nearly four decades and the survivor of countless assassination attempts, has never groomed a successor, and bristles at talk about who might follow him.
Mr. Abbas, who is also Mr. Arafat's deputy in the Palestine Liberation Organization, appears to be the logical heir if Mr. Arafat passes from the scene.
But, his age, his lack of a public following, and health problems — he was treated for prostate cancer several years ago — would not make him an automatic successor.
Mahmoud Abbas was born in 1935 in Safed, a hilltop town that is now part of northern Israel. His family fled during the 1948-49 war over Israel's creation, along with hundreds of thousands of other Palestinians, and the Abbas family landed in Syria. He earned a law degree in Damascus, followed by a doctorate in history from Moscow Oriental College.
Mr. Abbas wrote a book called "The Other Side: The Secret Relationship Between Nazism and the Zionist Movement," which claims that the number of Jewish Holocaust victims was not six million, but was less than one million. According to the Anti-Defamation League, Mr. Abbas was asked about the book when he rose to prominence in the mid-1990's. "When I wrote `The Other Side,' we were at war with Israel," Mr. Abbas told Maariv. "Today I would not have made such remarks."
After helping to found the Fatah movement and always held ranking posts that kept him in close contact with Mr. Arafat. But during the decades in exile, Mr. Abbas was little known to Palestinians living in the West Bank and the Gaza Strip.
He was among the first Palestinian political leaders to recognize Israel, and returned in 1995 and has been living in Ramallah in the West Bank, becoming the No. 2 man in the P.L.O. hierarchy a year later.
Mr. Abbas is married and had three grown sons, though the eldest, Mazen, died last year of a heart attack at age 42.
