The Moviegoer Shock Corridor at room 10-250, M.I.T., tonight, 8 and 10 p.m.

SAMUEL FULLER is probably the greatest social critic among America's film-makers. "Most people say [social contradictions] should be left to the newspapers. But I say, on the contrary, that it is necessary to give them a dramatic form." For Fuller 'giving them a dramatic form' means more than inventing a plot that sets out right and wrong and a hero who battles for the good. None of his characters are aristocrats standing above society. Vulnerable without being weak or sentimental, they are beaten when they try to achieve their goals by ignoring some condition of social reality.

The hero of Shock Corridor (1963) is a reporter obsessed with winning the Pulitzer Prize. After a year of training with a psychiatrist, he feigns neurotic incest- wishes to get committed to a certain asylum. Here live three patients, sole witnesses to a murder whose perpetrator they are unable to reveal. Making friends with them, he helps them recover their rationality so they can reveal the murderer's identity. But he becomes excited and loses control at each witness's moment of revelation, driving each back into insanity without discovering the vital name. Surrounded constantly by sights and sounds that belong as much to nightmare as to conventional reality, he eventually goes insane. The film's last shot tracks down the asylum's main corridor past the three men he helped and then destroyed, to him fixed in a state of catatonic schizophrenia.

Various interpretations of this strange plot suggest themselves. One stresses retribution both moralistic and Freudian. The hero entered the asylum to exploit its patients, to use them as sources of information rather than as humans. The plot comes full circle, making him mad through the ravings of those he tried to use. Its symmetry is expressed in a typically explicit line of Fuller dialogue: "What an irony- an insane mute winning the Pulitzer Prize."

Shock Corridor also criticizes American go- gutter ideals. Its hero, obsessed with making it, tramples on others including his girl friend- a stripper, a social outcast. Dreams of her calling to him help drive him insane. The asylum's other inmates are even more explicitly victims of social contradictions-anti-Communism and race hatred.

But if this were all there is to Fuller's intentions, Shock Corridor would be quite a dishonest movie. Insanity is too serious a situation to hang social criticism upon; the human realities it involves require a concern with personal experience, with the roots of neurosis and schizophrenia. At first Fuller seems to ignore those roots; his direct dialogue and shooting style seem typical of B- picture sensationalism. But the simplicity of his dramatic and visual approach does not bar a truthful and deep treatment of his subject, however much it initially seems to lack subtlety.

FULLER'S simplicity and directness come from his belief in the closeness, indeed inseparability, of interior and exterior experience. No bodily barrier can keep the events that assail a character from affecting his mind. Fuller's heroes live in situations involving the most extreme contradictions, the strongest contrary pulls on them. They remain forceful and decisive; Fuller doesn't represent the depth of social contradictions by detailing lengthy processes of decision, by creating vacillating characters. But contradictions take their toll on his tough guys after they decide what to do.

Merrill in Merrill's Maranders decides to keep marching onward, probably to extermination. His decision denies the validity of physical and psychological fatigue; but this side of human existence revenges itself upon him. In the final push, mustering his men, he drops from a heart attack. In his exhortation immediately before he is clearly insane, he orders men forward against their bodies and wills for some maniacal purpose. Having stressed one aspect of reality and denied the other, he is stricken down by what he denied.

This takes place more in a realistic than a moral context. Fuller never says Merrill, or the reporter, is wrong. The Marauders do take their objective; Shock Corridor is "the magic highway to the Pulitzer Prize." Not having enlisted much audience sympathy for his hero, Fuller does not reverse the plot against him at the end. Instead he follows him through a world constantly informed by the duality that drives him mad.

Insanity, the direct consequence of intolerable contradictions, is thus an objective fact, not a subjective claim on sympathy. We see the nightmares that plague the reporter's imagination and equally hear the cries of demented patients around him. Objective and subjective, exterior and interior experience become a single attack on his sanity. Fuller's direct way of showing his hero's experience is not crudely simplistic. We must be able to see everything that happens; the experiences of his characters have to be open.

This openness is the chief virtue of Fuller's style. One of its most wonderful accomplishments comes during the reporter's three meetings with the three insane witnesses. Fuller simply cuts together one- shots of the two men, showing first the reporter and then the other. Unlike most directors' one- shot cutting, this is free of self/other conceptions; it does not suggest some insidious link between their personalities. One does not see himself in the other; each is unified and individual. The cutting confronts one with the other. It also puts them together in the same situation, and to that extent links them morally. Because our knowledge of these men depends on no quality of subjectivity or identification, because all their experience is so directly presented, we can see their confrontation without adding associations foreign to their actual situation.

The vulnerability of Fuller's characters proceeds naturally from their unity, If events affect them at all they must affect them entirely. The full measure of their engagement in society is seen in their insanity, an insanity all the more disturbing for its lack of sentimental gloss. Only Fuller could have gotten away with beginning and ending a B picture with a quote from Euripides. His ability to integrate tough realistic directness with terrifying personal experience makes him one of the few living tragedians. But not one of the practicing tragedians; he can't find backers for any of his recent projects. The Hollywood studios think he's crazy.