"There are no more thresholds to cross! We are in the cataclysmic age," said General E. L. Burns, former Canadian Representative to the Eighteen-Nation Disarmament Conference, to a crowd of 300 which barely filled half of M. I. T.'s Kresge auditorium yesterday afternoon.

Burns' talk was part of the agenda that concluded a two-day symposium on the arm race and the unilateral proliferation of nuclear weapons. The symposium, sponsored by the Union of Concerned Scientists, a group of Boston-area scientists, is designed to disseminate information to the public concerning the danger of nuclear arms buildup.

Joining Burns on the program was I. F. Stone, publisher of I. F. Stone BiWeekly.

Burns told the audience that he is concerned mainly with two facets of the nuclear problem: the vertical increase of nuclear armaments being built by the major nuclear powers and the horizontal addition of near-nuclear countries who now have the capabilities to build a nuclear weapon and whose entry into the nuclear family could cause wholesale thermonuclear escalation.

Burns stated that there are four countries now capable of producing a nuclear weapon: India, Japan, Israel, and West Germany. He said that these countries are looking forward to the results of the Strategic Arms Limitation Talks (SALT) which will be held April 16 between the United States and Russia before making their decisions as to whether each will go ahead in its nuclear program.

Burns pointed out that recent failures of the U. S. and U. S. S. R. to keep promises concerning test-bans and disarmament, notably the US. continuation of underground tests following the Nuclear Test-Ban Treaty of 1963, will cause skepticism concerning the efficacy of the talks.

Stone agreed, saying, "I have no faith whatsoever in the SALT talks, no faith whatsoever in disarmament negotiations." He described the ABM as a system designed "as a first-strike capability to get China and have enough left over to save one or two U. S. cities from China's last nuclear gasp."