Sen. J. William Fulbright warned last night that whatever the future course of East-West relations should turn out to be--and he said it might be very favorable for the West--the United States must remember that "the mature nation, like the mature man, is one which has made a workable accommodation between its aspirations and its limitations."

Speaking as Tufts University's 1963 Clayton Lecturer, Fulbright (D.-Ark.) made clear that he has little use for that way of thinking which sees "total victory" as the goal of all U.S. policy. But he said that through a restrained and responsible use of its power, the United States could check the spread of Communism, and could hope to "shape its destiny toward the fulfillment of the highest values of our civilization."

Call For Moderation

The chairman of the Senate Foreign Relations Committee opened his call for moderation by pointing out if the West pursues a firm and patently rational policy, then Soviet Russia will follow a policy that is equally sane. Emphasizing that the Communists are unlikely to begin a nuclear war, he quoted George Kennan's observation that "the theory of the inevitability of the eventual fall of capitalism has the fortunate connotation that there is no hurry about it." Fulbright compared the Communists to Hitler's Nazi Germany, observing that "neither Stalin nor his successors have exhibited anything like the suicidal mania of Hitler's Germany."

But, said Fulbright, even if the Russians have no plans for open warfare, "neither are they likely to commit fatal blunders of judgment which will lead to defeat and destruction." He said that in taking account of Russia, the United States must bear in mind that it is dealing with a nation accustomed to "patience, circumspection, and flexibility."

He warned, moreover, that beneath the patience that characterizes Russian foreign policy there is a "constant probing for opportunities to expand Soviet power wherever it can be done without excessive risk." The West, therefore, can count upon Soviet moderation and restraint "only to the extent that it is absolutely clear in keeping the Soviets informed about where caution must be observed." "This in turn," he said in passing, "requires Western leaders to be absolutely clear in their own minds as to the boundaries of Western interests."

Fulbright discussed East-West relations not only in terms of maintaining the borders as they now stand, but also with respect to the questions that might be raised by a shift favoring the West in the balance of power.

He said that the way for the West to achieve such a shift was not through direct military action, but through "the utilization and unification of its immense human and material resources, to strengthen the internal fabric of the free societies." Not only would this make the democracies "impregnable to external ideological assault," but also "magnetic examples of social justice and material well-being for the entire world."

A trend in this direction has been evident in the affairs of the West since the end of World War II, Fulbright declared. In the current revival of Western Europe, he saw a potential continuance of the trend toward democratic solidification, but also a potential crisis; and he foreshadowed the substance of tonight's lecture by nothing that whether the West "fulfills the promise of unity or becomes divided against itself" is the most important of all United States foreign policy questions.

But even if Western unity is possible, achieving it will by no means solve all the West's problems, Fulbright predicted. In fact, he suggested that "the narrowing of the horizons of Soviet ambition in the face of growing Western strength and unity could conceivably lead irresponsible or incompetent leaders into some desperate gamble to reverse the tide." The dangers, Fulbright said, are obvious: "When a great power is confronted with an increasingly unfavorable disequilibrium in the scales of world power, it may be tempted to act rashly to reverse the trend."

Fulbright admitted that he does not know "precisely how the West can deal with this potential problem," but he saw hope that the West, by keeping before the Russian people the contrast between reality and the illusions of Marxist theory, could win the Communist nations away from "the dream of a world remade in the Soviet image.