As one of the loyal Old Boys who keeps up with the affairs of his alma mater -- the Kent School in Kent, Conn. -- James L. Tyson, '35, had a disappointment. There, on Page 1 of the Kent News, the student newspaper, was a photograph of four Sandinistas in a jungle camp in Nicaragua. Amplifying this unpreppy scene, an accompanying story told of two guest speakers who spoke to the 600 Kent students in chapel against a U.S. policy in Nicaragua they believe is inhumane.

Since the speeches, the serene life at Kent -- a private and proper Episcopalian boarding school in northwestern Connecticut with a yearly tuition of $10,800 -- has been roiled with controversy. An ideological war zone has been created in which alumni who criticize the Reagan administration's policies in Nicaragua are finding themselves attacked by other alumni who see American intervention as all but divinely inspired.

Tyson, who went on to Harvard, Time-Life and IBM, believes the Nicaraguan government is "a typical communist tyranny." Like Ronald Reagan, he sees the contras as "freedom fighters." Tyson's concern for the developing minds at Kent -- and the possible damage done to them by the two speakers -- prompted him to take action. He invited "any Kent students or faculty" to his Washington home during spring break. He offered "two guest rooms and kitchen privileges." Other privileges would include meeting with "experts" who could balance "the one-sided point of view" the students previously heard in chapel.

In a few days, 10 Kent boys and girls are scheduled to come to Washington. They will not be staying with Tyson, but he is one of many in the capital with whom the children will confer. Others include Sen. Christopher Dodd (D-Conn.), a diplomat from the Nicaraguan Embassy, State Department officials, staff members of the American Security Council, some representatives of the contras and possibly a White House official.

The story of the Kent School and its sudden veering into the debate on Nicaragua illustrates that no one and no place -- not even the enclaves of privilege where the wealthy send their children to be expensively groomed -- are exempt from the demands of separating truth from propaganda.

Nicaragua was brought to the Kent campus by Cornelia Keller Biddle, class of '64 and a trustee. Last October, she and her husband, the Rev. Craig Biddle III, spent 10 days in Nicaragua and Honduras. At Kent a month later, both Biddles spoke, he to the boys, she to the girls.

Craig Biddle, an Episcopalian priest who is currently the director of IMPACT, an interfaith Washington-based peace and justice agency, counseled the students to pay attention to Nicaragua, if only out of self-interest. He said that if a decision is made to send an invasion force, "You, your friends [and] your brothers could well be part" of it. "Your future may be determined today by U.S. policy in Central America. You must become involved. It will become increasingly unpopular, as the days go by, to uncover the moral decay in our foreign policy toward Nicaragua . . . In the name of God, God's church and this country, learn all you can about the dangerous path we tread upon in Nicaragua before it's too late."

To James Tyson, the present danger includes the Biddles. In early March, he wrote the Kent student newspaper that, "The Soviet, Cuban and Nicaraguan propaganda organs have been working full time to influence opinion in this country. The Biddles were apparently misled in the tour they were given around Nicaragua."

Another Kent alumnus -- '23 -- wrote to chastise "our somewhat deluded" Mrs. Biddle. It was, he said, "a real shock to see the communist 'line' so flagrantly spread out for us, with a picture of the Red Star beret on a Sandinista guerrilla" in the Kent News. Still a third alumnus, the decibels rising, said that "Biddle is an unwitting traitor to his country, one of those liberals aptly described by the KGB as 'useful idiots.' " This alumnus, a classmate of Tyson, also expressed shock: Biddle "carries the message of godless communism into the very heart of a respected religious school . . . The chapel [was used] as a one-sided forum for the most evil empire in the history of the world."

The apocalyptic ire of the Old Boy network hasn't impressed the editors of the Kent News. In an editorial, they rejected the accusation "of printing treasonous, left-wing propaganda." They reminded the alarmed alumni that last year at a "foreign-policy symposium," speakers with different views than the Biddles had their day. Kent didn't fall apart then, and it isn't crumbling now.

Open-mindedness appears to be thriving at Kent, though not among some of the more excitable alumni. For Cornelia Biddle, the remembrance of such a spirit is what keeps her attached to the school: "At Kent they are developing the tools to think for themselves. That's what Kent did for me, and that's one of the reasons I went to Nicaragua and Honduras."