Pre-trial hearings opened in Boston yesterday in the case of Dr. Benjamin Spock, Yale chaplain the Rev. William Sloan Coffin Jr., and three others charged by the Federal government with conspiring to encourage draft resistance.

All of the defendants except Michael K. Ferber 2G were present in the U.S. District Court to hear their attorneys claim that their actions were protected under the First Amendment's guarantees of free speech, and that the indictment was so defective that it should be dismissed.

Not An Issue

But before considering the defense's motions to dismiss, Judge Francis J. W. Ford, 82, ruled that the legality of the Vietnam war is not an issue in the case.

Then, with the defendants and their battery of lawyers, relatives, and associates arrayed in a double semicircle around the courtroom, Ford listened to three hours of argument that the Jan. 5 indictment should be thrown out.

The five--Spock, Coffin, Ferber, Marcus Raskin, director of the Institute for Policy Studies in Washington, D.C., and Mitchell Goodman '46, a writer--are charged with conspiring to counsel, aid, and abet men to refuse military service and to violate provisions of the Selective Service Law.

Included as specific charges in the Government's case are the defendants' participation in the Oct. 16 demonstration at the Arlington St. Church, and in another demonstration four days later in Washington in which draft cards collected in Boston were turned in to the Justice Department.

"There seems to me no doubt that the turning in of a draft card is symbolic free speech," said James St. Clair, Coffin's attorney, adding that "the privilege of these defendants to oppose the action of their government is the traditional, classic thing that is protected by the First Amendment."

"The government cannot wash the First Amendment out of this case by framing the indictment to charge a violation of law," Telford Taylor, counsel for Raskin, said a few minutes later. "If this isn't a first Amendment case, there is no such case."

Taylor asserted that it is essential to be able to challenge laws on grounds of conscience, and that such efforts would be impossible if other men--such as the defendants--could not lend their support to the challengers.

Attacking the Justice Department's interpretation of the Selective Service law, Leonard Boudin, Spock's attorney, maintained that Congress never intended mere non-possession of a draft card to be a crime. Even if the regulations of Selective Service were violated, he continued, it would be "an extraordinary delegation of power to the Selective Service System" if every violation were considered a criminal act.

Boudin, too, insisted that no substantive crime had been alleged, and that the five were being prosecuted only for speech in the form of public opposition to the war and the draft.

After the five defense attorneys completed their arguments, Assistant U.S. Attorney John Wall spent much of his 15-minute reply rejecting their First Amendment arguments.

The five men "can disagree with the law from every platform in the country," Wall said, "but they cannot nullify the law by counselling others to break the law."

"Clear Incitement"

Wall also argued that if a legislature can prohibit an act, it can declare counselling the commission of the act illegal as well. "Symbolic speech it may have been," he said, "but it was also clear incitement not to cooperate with the Selective Service System in any way."

The defense attorneys also attacked the indictment itself as impermissibly vague. By claiming the defendants took part in a nationwide draft resistance movement without specifying its nature, Taylor said, the Government could introduce "evidence of a con- spiracy to assassinate General Hershey and kidnap members of the draft boards." The indictment's vagueness, the defense lawyers said, made it impossible for the five men to know what evidence would be produced against them, or how to prepare to refute it.

Although 1,000 demonstrators accompanied the five men to Post Office building on Jan. 29 for their arraignment, only a few television cameramen greeted them yesterday. The only remarkable event outside the courtroom resulted when a giant crane overturned on Congress St. during the hearing. Spock strolled over during the lunch recess to inspect the wreckage.

The preliminary hearings resume at 10 a.m. today. Ford will announce his rulings on the defense motion shortly after the hearings are completed. He is expected to set a trial date at that time if the motion to dismiss the indictment is denied