Only a few clergymen devote themselves to the prison ministry, and of those few only a tiny number ever challenge the institutional mindset that justifies imprisonment. If anything prison chaplains often add a veneer of unwitting approval to the debasing conditions that are the daily torment of criminals who could as easily - and inexpensively and humanely - be punished in other ways.

A stirring example of genuine prison ministry is currently available in the stand of conscience being taken by the Rev. Maurice McCrackin of Cincinnati. The 73-year-old pastor of that city's West End Community Church has taken on the Ohio courts in a nervy display of defiance that is in the ageless tradition of prophetic resistance to state-sanctioned injustice.

McCrackin's troubles - or more accurately, the State of Ohio's troubles - began in January when the minister refused to appear before a grand jury that wanted to ask questions about two escaped convicts who had kidnaped McCrackin two months earlier.

After the abductos were captured and McCrackin was released unharmed, the minister's appearance before the grand jury was expected to be simple and routine.

But the legal establishment of Cincinnati - from the Hamilton County prosecutor who is known as an ardent advocate of the death penalty to the attending judge - did not realize that McCrackin saw a direct link between his cooperation with the system and the systemhs blessings of prison. When the pastor not only refused to talk to ghe grand jury but refused also to invoke any of his constitutional protections as a clergyman, he was jailed.

For those who may have thought this was another example of Cincinnatihs dislike of the rowdy and unseemly - the same county prosecutor won national attention two years ago in getting an obscentiy conviction against the publisher of Hustler magazine - McCrackin spelled out clearly that he should not be the object of anyone's anger. He wrote from jail:

"How can I go and testify against a prisoner on behalf of the state, or even seem to be doing so by going before a grand jury, when it is the State of Ohio that is responsible for the vast injustice, degradation and horror that is [the] Lucasville [prison]? Appearing would be a moral compromise that I am not prepared to make. Nor would I betray the trust that prisoners . . . might have placed in me."

McCrackin has been in the Hamilton County jail since Jan. 19. He went on a liquids-only fast that lasted 21 days. On April 16, he began a second fast. With McCrackin now held in isolation, friends fearing for his health learned the other day just exactly how firm the minister's beliefs have become: "Please don't take any legal steps or make contact with any judges [for my release]," he wrote. "This is strictly a moral struggle and I want it pursued outside the court setting."

The stand of Maurice McCrackin has brought national attention to the prisons of Ohio at a time when an expanding coalition of citizens, judges, clergy and correction officials is involved both specific prisons and the idea of imprisonment.

Earlier this year in Sweden, in a unique case, the U.S. Embassy went before that country's Supreme Court to ask that an American be extradited because he was a convicted felon who had jumped bail and fled to Uppsala, Sweden, before imprisonment.

The Swedes refused to cooperate. The court wanted no part of a process that would condemn a person to the inhumane conditions of an American prison.

In addition, the Swedes balked about the sentence of 59 years. The American, a Kentucky physician, had been convicted of sexual offenses against children, one of the most repugnant crimes. But to the Swedish mind, a sentence of 59 years in a U.S. prison had a repugnance of its own.

According to Alvin Bronstein, director of the National Prison Project for the American Civil Liberties Union, this is the first time a foreign nation has refused to extradite a person in a nonpolitical case because of American prison conditions.

Bronstein, who assisted the Swedish court in reaching its decision, says that the physician currently receives psychiatric care, is living with his family, regularly reports to the court and works in a Swedish hospital.

Although it is too much to hope that other countries will refuse to send back American felons to our prisons, the defiance of the Swedish Supreme Court is bracing news. Suddenly the whole world is in on the dirty secret that a few Americans like Maurice McCrackin have long known.

Whether we can be shamed into reforms is now the question. It isn't that the abysmal reality is not common knowledge: Imprisonment does not stop crime, it is extravagantly costly and conditions run from the inhumane to the squalid. It is equally known what does word: programs for alternative sentences, restitution, halfway houses and early parole.

A touch of initiative can get results. In Washington, Sister Judith Schloegel, a Catholic nun working for Lutherans Involved in Ex-Offender Employment Opportunities, goes to the Lorton prison once a month to stand up for parolees. In 1978, she found 67 quality jobs for ex-offenders with a recidivism rate of 5 percent. The national rate has been as high as 80 percent.

The spunk and foresight of this lone Catholic sister is foreign to the dim thinking that dominates the federal Bureau of Prisons and the congressional committees that oversee it. "The critical problem" of overcrowding is regularly bemoaned. Congress keeps open the money tap to build more and more prisons, and bureau officials seldom waver from the lock-em-up line.

This pattern is so entrenched that Mareica is joined by the Soviet Union and South Africa as the Big Three among the world's jailers. The National Moratorium on Prison Construction reports a per capita incarceration rate of 250 per 100,000 in the United States. In France, the figure is 56 per 100,000. The Netherlands is 22 per 100,000, less than a tenth of America's. In the Netherlands, the average sentence is 35 days, while nearly three-fourths of all U.S. sentences are for four years or more.

While the statistics remain mostly on the outer rim of public consciousness - even then a large bloc of citizens believes that courts should be imprisoning five and 10 times the number now sent away - they are brought into sharp focus whenever a Maurice McCrackin makes himself heard.

As a pacifist who did six months in federal prison in 1958 for refusal to pay taxes that go to Amerian militarism, McCrackin sees himself in the traditional role of the pastor-as-educator. Americans don't know much about prison conditions, he wrote to a friend the other day. "But when we do find out, many will says as the Germans said of the concentration camps - 'We had no idea such horrors existed.'"

McCrackin's vocation has been to confront the horrors himself and then use whatever pulpit is available - a prison cell the past three months - to spread the word that they exist.