A Montgomery County high school English teacher was suspended for one month without pay early today for teaching Aristotle and Machiavelli to his 10th grade students.

By a 4-to-3 vote, the Montgomery County Board of Education found Cyril Lang, 55, guilty of misconduct and insubordination for defying the orders of his principal not to include the works in his course after county curriculum officials had decided they were too difficult for 10th graders.

The decision upheld a recommendation by County School Superintendent Edward Andrews that Lang be disciplined, but it reduced drastically the penalty of seven months without pay that Andrews had recommended.

After the decision, Board President Carol F. Wallace, who voted with the majority, said, "Academic freedom is not the issue in the case . . . The message I hope would come from this is that there are prescribed ways of disagreeing with the materials that are allowed to be used [in county schools] -- Mr. Lang didn't use them."

Board member Blair G. Ewing, who had voted in support of Lang, said the board's action 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 and 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 challenged the received opinions on what you should do."

Lang, who taught at Charles W. Woodward High School in Rockville, called the decision "a defeat for teachers" and said he would appeal it to the Maryland State Board of Education.

Since last August Lang has been suspended from teaching but has continued to draw his salary. He has worked in the school system's research department since November.

Under last night's board order, Lang's suspension will begin May 13 and run until the last day of the school term, costing him about $2,500 in salary.

The board's decision was announced shortly after midnight, following two hours of spirited public argument between attorneys for Lang and Superintendent Andrews and a two-hour private session in which Wallace reported that the board members had a "vigorous discussion."

Charles Reese, the attorney for Andrews, said the crux of the case was "one teacher's insistence that he teach and test on whatever he wants, even if it violates the policies and regulations this board of education has legally adopted."

He described Lang as an "indifferent . . . [and] lazy" teacher who "sought to save himself from the condequences of his own deliberate misconduct by masquerading as a champion of academic freedom."

James Whattam, a lawyer for the Maryland State Teachers Association who represented Lang, said the accused teacher did not deliberately flout school policies against using non-approved books but "attempted to give his students just a little bit more than the prescribed curriculum called for." He said Lang used passages from the two books -- Aristotle's "Poetics" and "The Prince" by Machiavelli -- to help students get a better understanding of Shakespeare's "Julius Caesar," which is part of the county's 10th grade curriculum.

Whattam said there were no complaints that the two classics were obscene of subversive. He charged that the supervisors who insisted that Lang stop using them had a "fear of the unknown, a fear of the slightest departure from their 'Bible,' the curriculum."

The case became the focus of nationwide attention as Lang's supporters portrayed him as a determined defender of a teacher's right to teach more than the minimum curriculum. Superintendent Andrews and most of Lang's other supervisors said the issue revolved around the right of the school system to establish a sequential curriculum and the obligation of teachers who follow it.

Before last night's board meeting, testimony in Lang's case was heard for five days -- spread through December and January -- by hearing examiner Joseph Sickles, a Bethesda lawyer. He agreed with Superintendent Andrews, and recommended that Lang be suspended without pay for half a year.

Despite warnings, Lang based two-thirds of the semester examination in June on the two books.

Lang said only about one-third of his students -- all volunteers -- read parts of each work for extra credit. They then made reports to the whole class and Lang then lectured on the works.

Last night's board meeting drew about 100 persons to school board headquarters in Rockville, including several dozen students from Woodward High. Many of them went up to Lang and wished him well.

Besides Wallace, the board members voting against Lang last night were Marian L. Greenblatt, Elizabeth W. Spencer and Eleanor D. Zappone. Voting for him were Ewing, Joseph R. Barse and Suzanne K. Peyser. Traci Williams, the nonvoting student member, announced that the supported Lang.