The Supreme Court ruled yesterday that charges of inhumane conditions at the D.C. Jail could not be used to justify a 1976 escape by four prisoners.

The Court stopped short of saying such a defense could never be used, but anyone who wants to try it, it said, has to surrender immediately after making a break in order to show good faith.

The 6-to-2 decision prompted a strongly worded dissent from Justices Harry Blackmun and William J. Brennan. Citing the "atrocities and inhuman conditions of prison life in America," Blackmun said that escape may be one of the few "realistic avenues of redress" open to the prisoner.

The "conditions that led" to the escape "continue unabated" at the D.C. Jail, he said. "It seems too much to demand that in order to preserve their legal defenses [the four escapees] return forthwith to the hell that obviously exceeds the normal deprivations of prison life and that compelled their leaving in the first instance."

The Court's ruling reversed a D.C. Court of Appeals decision last July that let a jury consider the D.C. Jail conditions as a possible justification for the escape in September 1976.

The four -- Ronald Cooley, 21, James T. Cogdell, 38, Clifford Bailey, 34, and Ralph Walker, 27 -- escaped from a maximum security section of the jail by entering a cell in which three bars had been removed and lowering themselves to the ground with bedsheets.

At their trial on the escape charges, the four men were allowed to present evidence that there had been frequent fires at the jail that had burned out of control, poor ventilation, threats and beatings by guards and that one of the inmates had been denied medical treatment.

The jury was told not to consider these factors in rendering its verdict, which turned out to be guilty.

The Court of Appeals reversed that verdict setting up the Supreme Court appeal.

Justice William Rehnquist, who wrote the majority opinion, said any other decision would "undoubtedly convert every [escape] trial into a hearing on the current state of the federal penal system."

Rehnquist called the D.C. Appeals Court ruling "quite unsupportable" and "not even close."

Once a prisoner has fled the bad conditions that he says prompted his escape, Rehnquist said, he no longer can justify it on those grounds. Thus he must immediately surrender or make a "bona fide effort to surrender." Under the law, such an effort is "indispensable" to the defense that "duress" at the jail prompted the escape, Rehnquist said.

D.C. Corrections Department director Delbert Jackson said late yesterday afternoon that the inmates' defense was "most certainly not applicable" in the escape at issue here, since the prisoners fled the new D.C. detention center.

He said Justice Blackmun's remarks about continued poor jail conditions were mistaken, and that he must have been "talking about the old D.C. Jail" -- the focus of a wide range of lawsuits and charges of inhumane treatment. "A lot of people make that mistake," he said.

Jackson said he had not yet read the Supreme Court opinion and would not have any further comment until he did.

"This case presents a good example of the potential for wasting valuable trial resources," Rehnquist wrote.

". . . It was presented with evidence of every unpleasant aspect of prison life from the amount of garbage on the cellblock floor to the meal schedule to the number of times the inmates were allowed to shower. Unfortunately, all this evidence was presented in a case where the defense's reach hopelessly exceeded its grasp." Chief Justice Warren Burger and Justices Potter Stewart, Byron White, Lewis Powell and John Paul Stevens joined Rehnquist. Justice Thurgood Marshall did not participate.

Blackmun and Brennan said that the majority's view "might be a proper one were we living in that ideal world, and were our American jails and penitentiaries truly places for humane and rehabilitiative treatment of their inmates.

"The complaints that this Court and every other American appellate court receives almost daily about conditions of incarceration, about filth, about homosexual rape and about brutality are not always the mouthings of the purely malcontent.

". . . Prison officials either are disinterested in stopping abuse of prisoners by other prisoners or are incapable of doing so, given the limited resources society allocates to the prison system. Prison officials often are merely indifferent to serious healthe and safety needs of prisoners as well.

"Even more appalling is the fact that guards frequently participate in the brutalization of inmates. The classic example is the beating or other punishment in retaliation for prisoner complaints or court actions," Blackmun and Brennan wrote.

"The evidence submitted . . . in this case fits that pattern exactly."

"The real question presented in this case is whether the prisoner should be punished for helping to extricate himself from a situation where society has abdicated completely its basic responsibility for providing an environment free of life-threatening conditions" for prisoners.

At least, the dissenters said, a jury should have been allowed to consider these issues.