It always comes as something of a surprise to me to find that the most vociferous defenders of individual rights seem willing to run over the rights of other individuals whenever they perceive themselves to be a majority. This apparently is the case again in regard to the Supreme Court's recent decision on student newspapers as viewed by columnists Colman McCarthy {Style, Jan. 24} and Nat Hentoff {op-ed, Jan. 23}. Both regard the student journalist's rights as more important than those of the citizens and parents who support the schools that publish the newspapers.

Even more surprising, however, is their inclination to impute sinister motives to large groups of people they do not know, in this case the principals of high schools. In commenting on a student editor's opinion that the Supreme Court decision deprives him of his constitutional rights, Mr. McCarthy observes: ''This fundamental insight points to the unofficial motto of all too many school boards and principals: 'Students, you're here to think. Just don't get any big ideas.' '' Where did Mr. McCarthy discover this motto? It certainly doesn't come from any school with which we are associated.

It was also apparently not the motto of the Florida high school Mr. Hentoff describes, which has had a policy of noninterference with its student newspaper for the past seven years and which has reportedly indicated no intention of changing its policy as a result of the Supreme Court decision. Nevertheless, after reporting this information, Mr. Hentoff states, ''Elsewhere in the country, however, many principals are delighted, even exhilarated, at gaining full control of what's said or written.'' How did he learn this exciting information? Has he already conducted a nationwide poll? All we're offered as evidence of this proposition is the mention of one school that censored an AIDS story.

When I was in high school, English teachers called this kind of poor logic a ''glittering generality.'' When used by journalists, it was called ''unfair commentary.'' Perhaps Messrs. McCarthy and Hentoff themselves could have benefited from more careful guidance of their writing during their own high school preparation.

SCOTT D. THOMSON

Executive Director

The National Association of Secondary School Principals

Reston