SOMEWHERE in the back of their minds, many students have drawn on an image of the ideal revolutionary--a cold, analytical man who can nevertheless shift gears to deliver spellbinding orations. Ralph Schoenman fits that picture.

Schoenman, Bertrand Russell's aide and organizer of the tribunal which "tried" the United States for war crimes in Vietnam--can publicly denounce "U.S. imperialism" or "corporate capitalism" with appropriate emotion.

In private conversations, Schoenman presents another face. He modulates his voice carefully, ticking off the effects of U.S. anti-personnel weapons in a professorial, almost bored tone: "the guava bomb ... steel slivers, each one kills at 150 yards. The fields are pockmarked." Speaking from a profile position, Schoenman attempts to mesmerize the listener. He turns his hands over gracefully, or twists his head slightly to emphasize a point. Only furtive glances from his dark eyes to assess the impression he is making jar the effect.

Schoenman is no romantic. He dismisses those who have "romanticized" Che Guevara by emphasizing personal bravado, "at the expense of his vision." Che's vision--which Schoenman shares--is that of the continuing revolution. He quotes Che: "The struggle for the Cuban Revolution is the struggle for the extension of the Revolution in Latin American." Schoenman pauses, and then continues, "Elan is only a thing which can mobilize the people."

Bravado dismissed, Schoenman explicates revolution. Phrases like "analysis" and "objective conditions" flow easily from his lips. "It's all quite simple," he explains patiently. United States "corporate capitalism" needs to exploit the raw materials of the underdeveloped world. "Soldiers only enforce the oppression--its basic agency is the world market," he says.

THE New Left receives passing tribute for its radicalism, but criticism for lack of a strategy. "They say, 'We've got 200 people--let's make a revolution.' Well, you don't make a revolution that way." Schoenman's own revolutionary recipe centers on the "white working class" whom, he says, "bear the brunt or corporate capitalism." In a cold tone, he advises the radicals to continue demonstrations to gain mass support, foresake the "moral witnessing" of draft resistance, and begin longterm organization.

Schoenman's voice softens--perhaps accidentally, perhaps intentionally--when he discusses his undergraduate days at Princeton. A scholarship student from Brooklyn, he was then "already involved in the Black Struggle.... I was a socialist, but with a syndicalist or anarchist orientation." He "polemicized a bit" against the club system. "It was a training ground for the Southern aristocracy...stabbing one's friends in the back. I thought they were all so lifeless, so...bland, and so one dimensional."

After receiving an honors BA from Princeton in 1958, he went to the London School of Economics to study political philosophy. While participating in anti-nuclear campaigns, he met Lord Russell. Schoenman feels it is "very flattering, but a bit fatuous," to be considered the eminence grise behind the 95-year-old philosopher. "What's it done with--telepathy?" he asks sarcastically.

SCHOENMAN'S eyes blink as he praises Russell. "There have been various changes in his thought, but also a thread of consistency--his opposition to arbitrary authority and his defense of the oppressed." He denies that Russell is senile, and lists "this Renaissance man's" current projects: the second and third volumes of his autobiography, an "updating" of the New Testament (based on current events), a book of epigrams, and adaptations of his short stories for the stage.

Critics of the "war crimes tribunal" receive short shift from Schoenman. "We never represented it as a trial," he says, and compares the procedure to a "grand jury" for examining evidence without the "adversary process." He admits that the judges--including Jean Paul Sartre, Simone de Beauvoir, and Vladmir Dedijer--were already convinced that the U.S. had committed war crimes in Vietnam. "We're all conditioned...the question is how the evidence is dealt with," he says flatly. The tribunal felt that the Viet Cong had not committed war crimes. "Their resistance is a heroic chapter."

At present, Schoenman is working to spread the findings of the tribunal (neatly packed in a paperback book). He will return to England as soon as he can retrieve his United States passport which was confiscated by the Federal government after he took a trip to North Vietnam.

He describes his continuing aim: "To clarify, isolate, identify, and expose the contradictions of capitalism." Hardly words to arouse the masses but then it is Ralph Schoenman the professor of revolution speaking.