Two Law School professors yesterday struck out at "ill-advised" silent witnesses who withhold testimony on the grounds of self-incrimination in court or before legislative investigating committees.

In a joint statement, drawn up because "confusion has arisen about the use and limitations of the privilege of self-incrimination contained in the Fifth Amendment," Arthur E. Sutherland, professor of Law, and Zechariah Chafee, Jr., University Professor, called on the citizen to recognize "the duty. . .to cooperate in government."

"He (the citizen) is neither wise nor legally justified in attempting political protest by standing silent when obligated to speak," the pair hold.

Subpoena Power

"The citizen is ordinarily required, when summoned, to give testimony to a court, legislative committee or other body vested with subpoena power; and if he refuses to do so, he is punishable. Subpoena power has proved necessary to the conduct of government," the statement pointed out, under the guarantee an accused man shall "have compulsory process for obtaining witnesses in his favor."

"To this general duty of the citizen," the statement went on, "the privilege against self-incrimination is an extraordinary exception. . .(It is) criticized adversely by others because it makes police work difficult. . .(and) justified by others because it keeps government officers active in investigating the facts of offense, rather than relying on 'grilling' suspects."

Amendment Misconstrued

The statement quoted cases in which the Supreme Court and high state courts have upheld the right of such immunity, but added:

"There are several misconceptions about the testimonial privilege to remain silent. The witness is not the ultimate judge of the tendency of an answer to the question will tend, rightly or wrongly, to convict him of a crime. . .

A judge must decide when the witness has gone fare enough to demonstrate his peril."

Alibis Criticized

Thr professors elaborated that "more embarassment" was no excuse for withholding testimony or exhibition one's hands on television. They felt the witness must be "subjecting himself to some degree of danger of a criminal offense," to justify his reticence. Also ruled out as an alibi was "a sense of sportsmanship forward suspected associates." The Fifth Amendment, they observed, says nothing about one's friends.

As regards testimony relating to the Smith Act or the Communist party, the pair quoted Internal Security Act of 1950: "Neither the holding of office nor membership in any Communist organization. . .shall constitute per so a violation of. . .this section. . ."

They added, however,". . .the fact that disclosure of. . .association with the Communist party will cause trouble for the witness" in his community or among his associates does not excuse him from answering questions about it when duly subpoenaed.

"A witness who testifies without pretest to a part of his Community connection may find that he has lost his privilege of silence, and must tell the rest or stand punishment for contempt."

"A privileged refusal to testify is not an admission of guilt for the purposes of criminal persecution" the statement concluded, adding that its effect on popular opinion could not be legislated.