Attorney General Edwin Meese III said yesterday that under his command the Justice Department "will be fiercely independent, but this is not inconsistent with implementing President Reagan's philosophy, which represents mainstream political thinking."

Chief Justice Warren E. Burger administered the ceremonial oath of office to Meese in the Justice Department's Great Hall as about 500 department attorneys and other government officials looked on.

Meese first took the formal oath of office Feb. 25, in a private ceremony at the White House. His remarks yesterday gave the first indication since then of how he sees his role as the nation's chief law enforcement officer.

"Our ultimate success will depend on people in the nation supporting our objectives," Meese said. "There is a national consensus on issues such as crime."

Meese said his priorities were to protect "the law abiding from the lawless," to safeguard individual privacy, to defend the "civil rights of all Americans" and to promote "regulatory structures designed to expand economic freedom."

Meese said he would continue the policies of his predecessor, William French Smith, who was present. He has said he supports the department's filings of friends-of-the-court briefs and lawsuits on behalf of white men who say they have been discriminated against as a result of goals and timetables in affirmative-action cases.

He also has said he supports use of the "exclusionary rule," allowing evidence seized illegally to be used in court if police seized it in good faith that they were acting legally.

Meese said he would "encourage intellectual ferment and foster creative thinking" in the department, and that he would encourage "all manner of constructive criticism."

With a "team effort," he said, he wants to "address the problems of crime, combat terrorism" and fight white-collar crime.

He said he would work to protect the "rights of all Americans. The poor especially must find that the law works not only for those with deep pockets," he said.