In a strongly worded letter defending his controversial statements on the origins of grade inflation. Thomson Professor of Government Harvey C. Mansfield yesterday suggested that white professors and teaching fellows may have inflated black students' grades to support affirmative action policies.

The letter, addressed to the editors of The Crimson, seems unlikely to lessen campus tension surrounding Mansfield's remarks, which were first reported in the January February issue of Harvard Magazine.

Mansfield wrote that his latest comments would "not be the last" he issues on the subject. He is scheduled to speak on grade inflation again tonight as part of an Institute of Politics panel at the Kennedy School of Government.

In his letter, Mansfield referred to a letter written by Black Students Association (BSA) President Zaher R. Ali '94 to Dean of the Faculty Jere my R. Knowles, in which Ali called Mansfield's statements "Eurocentric, white supremacist informed beliefs.

"Although (ALI) favors affirmative action for Blacks in admissions, he opposes affirmative action in grading," Mansfield wrote. "Sad to say, when Black students first arrived at Harvard in the late '60s, many white teaching fellows and professors were unable to make this distinction. They passed easily from one kind of affirmative action to the other, overlooking the difference that Mr. Ali sees between them."

Mansfield wrote that other "ignoble influences" might also be historically linked to grade inflation, including "the desire of some professors to ensure that Harvard students would keep their draft determents, and an opinion (which is part of the reasoning behind affirmative action) that self-expression is diminished by being held to a standard of excellence."

Mansfield added that it would be difficult to determine the role each factor played in pushing up grades, saying professors may have deliberately obscured the influence of affirmative action in their grading.

"If I am right, professors over-graded all students to justify, and obscure, their over grading of Blacks," Mansfield wrote. He Called on Harvard administrators to release information about the admissions and relative performance of Black students so that a detailed analysis of grade inflation can be conducted.

Ali declined to respond to Mansfield's letter last night, saying he would likely comment on it today.

But in his earlier letter to Knowles, Ali questioned Mansfield's linking of grade inflation specifically to the growing Black student population, rather than to increasing numbers of all minority students. Ali also suggested that Mansfield thought Cs are "the grades [Black Students] really deserve."

But in an interview with The Crimson yesterday, Mansfield said he does not know whether Black students in general merited lower grades historically.

He said he does not know whether grade inflation still occurs. "It may happen," he said, "but it was a historical remark."

In a flyer distributed last Friday at a Junior Parents Weekend seminar on diversity, a coalition of nine student groups, including the BSA, demanded that Mansfield either substantiate or apologize for his remarks.

Along with several other demands--relating to academic issues and "Institutionalized racism" at the University--the coalition called on top Harvard administrators either to support or reject Mansfield's statements.

In a January interview with The Crimson, President Neil L. Rudenstine said he disagreed with Mansfield's theory, saying he believe changing cultural attitudes toward grades and hierarchy were the primary season for grade inflation.

Rudenstine reiterated that belief on Tuesday, but refused to agree with the coalition's characterization of Mansfield's comments as "racist,"

In a letter this week to Ali, Knowles also disputed Mansfield's argument, but demanded the professor's right to say what he believes.

Mansfield, in his letter to The Crimson, said the complaints to Harvard administrators about his remarks may suppress free speech on campus.

"I know that Mr. Ali did not mean to intimidate me by appealing to the authorities, but he should be warned that his action might inadvertently have that effect on others," he wrote. "My remark--and it will not be the last--was intended to widen the range of things that can be said publicity at Harvard."

Anna D. Wide contributed to the reporting of this story.