Colleagues are rallying to the defense of an eminent Harvard psychiatrist who quit as director of the McLean Hospital after admitting that he had committed plagiarism.

Scholars outside the University say that Harvard acted too hastily by accepting the resignation of Dr. Shervert H. Frazier, 67, on November 23. They say the school ignored Frazier's accomplishments by dismissing him over what one professor called a "trivial" matter.

Frazier's allies--many of them prominent health officials--charge that the University may have overreacted because of an earlier ethics scandal that has attracted widespread publicity.

"Harvard was using [Frazier] as some kind ofsacrificial lamb," said Dr. Alan Mirsky, chief ofthe psychology laboratory at the NationalInstitute of Mental Health.

"It was a shabby way to treat a distinguishedscholar. I don't understand it," Mirsky said.

But University officials have said that as aviolation of academic standards, plagiarism is aserious offense and warrants strong punishment.

Frazier, 67, resigned after a four-monthinvestigation by the Medical School's FacultyConduct Committee found he had plagiarizedmaterial in four articles published between 1966and 1975. The articles did not purport to beoriginal research, and until now, were minorfootnotes in Frazier's career, colleagues said.

Frazier taught at the Medical School from 1972to 1984, when he left to become director of theNational Institute of Mental Health. He returnedto the University in 1986 to become director ofHarvard-affiliated McLean hospital.

While Frazier admitted to the committee that hehad plagiarized information, he said it had beeninadvertent and attributed it to carelessscholarship. Frazier could not be reached forcomment yesterday.

`Just Too Much'

Paul C. Scatena, a medical student at theUniversity of Rochester, uncovered three of thearticles while doing research on a phenomenonknown as phantom limb pain, and notified Harvardin August. The case was first made public Mondayafter Frazier's resignation.

Scatena said yesterday he thought theUniversity had investigated the matter thoroughlyand efficiently. "Harvard's actions were entirelyappropriate. The school did a good investigation,"he said.

Scatena disagreed with Frazier's claim that theplagiarism was completely inadvertent.

"When you examine the actual papers, theevidence is quite clear. I don't think anyonecould look at this and say, 'This was a a seriesof mistakes.' There is just too much," he said.

Dean of the Medical School Daniel C. Tosteson'44 told The New York Times that Harvard's actionswere warranted because of strict University policyregarding plagiarism.