School officials yesterday praised the decision by the Montgomery County Board of Education to suspended high school English Teacher Cyril Lang for teaching Aristotle and Machiavelli in his 10th grade classes without authorization, but Lang's supporters expressed fears that the punitive action would make it more difficult for good teachers to challenge their students.

The board voted 4 to 3 early yesterday to suspend Lang for 28 days beginning May 13, a penalty that school personnel officials said would cost him $3,293 in lost salary. Next fall Lang, 55, will be allowed to return to the classroom, a county school spokesman said, though probably not at Charles W. Woodward High School in Rockville, where he had clashed repeatedly with the principal.

Although the penalty was far lighter than the seven-month suspension that Superintendent Edward Andrews had recommended, Kenneth Muir, a spokesman for Andrews, said the superintendent was satisfied with the outcome of the hotly contested case.

"It was the superintendent's intention to be vindictive about the thing," Muir said. "The principle of the matter is the important thing, and that has been upheld by the board. . . . Here is a teacher who did not choose to follow the cirriculum that had been developed and did not follow the procedures for changing it. . . . Superintendent Andrews is very much in favor of the rights of teachers to be creative, and he believes that can be done within the cirriculum of the school system."

The board found Lang guilty of misconduct and insubordination for defying the orders of principal Anita Willens to stop requiring all students to master key points from the two classics and basing two-thirds of his final exam on them last June. County curriculum officials had decided that the books were too difficult for 10th graders.

After the board vote, however, member Blair G. Ewing, who had voted in Support of Lang, said the decision would make Montgomery County the "laughing stock of school systems in the United States." He said the arguments made against the teacher were "totalitarian justifications for controlling what may be taught and read thought in our schools."

Ewing said the decision would have a "chilling effect on teachers" and would tell them, "Do not . . . make any arguments that challenge the received opinions on what you should do."

In a telephone interview, Robert F. Hogan, executive director of the National Council of Teachers of English, which earlier had sent a letter supporting Lang, termed the decision "unfortunate."

"Mr. Lang sounds like a very educated, very informed, very exciting teacher," Hogan said. "It seems to me that they violated his First Amendments rights."

Lang himself called the decision "a defeat for teachers" and said he hoped to appeal it to the Maryland State Board of Education after the county board issues a written decision, which it has scheduled for May 12.

"It would be very difficult to go on [teaching]," Lang said, "without some kind of exoneration. I'd have to be looking over my shoulder again and again . . . Of course, there has to be a curriculum. But you need some autonomy within that classroom, and when you get a very narrow, wrong order [from a principal or supervisor], yes, you do have the right to disobey."

Shortly after he was accused by Andrews last October, Lang said that the books he was using -- Aristotle's "Poetics" and "The Prince" by Machiavelli -- weren't "subversive. They weren't [sexually] offensive. They were kind of tough. . . .

"Why should that be a problem in a so-called enlightened school system that talks about raising standards?" he said. "I felt there are certain constitutional rights of free expression that a teacher has in a classroom. If you take that away, you take away the art of teaching and you might as well just have textbooks and baby sitters and movie machines and that's it."

Andrews countered in an interview, "In a public school system you have to have reasonable procedures to determine what is to be used, and the superintendent has to uphold them. . . .

"Either we have a public school system and we have accountability to the public that supports it," Andrews continued, "or we have 6,000 teachers out there doing whatever they want to do. What if a teacher decided to use 'Playboy' or 'Hustler' or go down that road? Is that OK? I say no."

Lang said he had used the two classics to help students get a better understanding of Shakespeare's "Julius Caesar," which is part of the county's 10th grade cirriculum. In each of his classes, he said, only a few of the ablest students -- all volunteers -- read parts of the books which illuminated Shakespeare and then made reports to the whole class. Lang himself lectured on the works and distributed outlines of the main points for which all students were responsible for two-thirds of the final exam.

However, Willens, the principal, said it was "unfair to hold everybody responsible for material that only a few students had read. It's all right to use [non-approved books] for enrichment, but the policy in Montgomery County is that examinations should clearly be based on the curriculum, and his wasn't."

Willens said she ordered Lang to change the exam questions, but he refused, and she began disciplinary action against him.

Voting against Lang at the board meeting were president Carol Wallace and members Marian L. Greenblatt, Elizabeth W. Spencer, and Eleanor D. Zappone. Besides Ewing, those supporting him were Joseph R. Barse, and Suzanne K. Peyser.