ROME, Dec. 16—Pope Paul VI today called for peace based on justice, not peace “imposed only by superiority of power and force.”

The appeal contained no direct reference to the war between India or Pakistan or any other current conflict.

Commenting on the papal document at a news conference today, a Vatican official, the Most Rev. Ramon Torrella Cascante, said that “concrete steps” for mediation had lately been taken on the Pontiff's behalf in such crises as those on the Indian subcontinent and in Northern Ireland. “Not all such initiatives succeed,” the Spanish‐born Bishop said, “and, owing to reasons of reserve, it is not possible to speak about all of them.”

The Pontiff's message urged “men of thought, men of action, all mankind living in 1972” to join the Roman Catholic Church in observance of its Day of Peace, Jan. 1.

The Church's international peace day was instituted by Pope Paul and first celebrated on Jan. 1, 1968.

During the next few days Vatican envoys will present to heads of state, including President Nixon, the text of the pontifical appeal that was issued today. Vatican sources also said that semiofficial channels would be found to convey the Pope's message to Moscow and Peking.

Well‐placed sources in the Vatican suggested that today's peace appeal was the first of a series of initiatives and documents that Pope Paul had prepared for the Christmas period. The sources said that the Pontiff's projected moves might include a reform of the method of electing his successor.

Speculation about forthcoming changes in the rules governing the assembly of Cardinals that elects a new Pope has lately found its way into the Italian press. According to one theory, Pope Paul envisages a reform that would radically depart from a tradition of many centuries by admitting to the conclave some ecclesiastics who are not Cardinals, and perhaps even some selected laymen.