"We often live off our own propaganda" in establishing policy toward Europe, General James Gavin, former Ambassador to France, told a Social Sciences Forum at Winthrop House last night.

Gavin, now president of Arthur D. Little, Inc., economic consultants, emphasized three "illusions," held in the State Department two years ago, that are showing up now in strained Franco-American relations. Some policy-makers then believed that President de Gaulle "wouldn't last long," that his nuclear policy would prove unpopular within France, and that "he wouldn't get rid of Algeria."

The reality, said Gavin, is that de Gaulle has greatly stabilized the French political scene, brought the French economy to an unprecedented prosperity, and effectively proffered his vision of a strong, independent Europe within NATO.

Gavin was pessimistic about prospects for Britain's entering the Common Market. "De Gaulle is adamant," he said. "The new Europe is going to unite in every possible way and if the UK went in, she'd have to go in with every national resources."

He said the Conservative Government has been unwilling to do this, and "the Nassau Agreement, following the Skybolt decision, merely highlighted this fact."

These "grim prognoses" are further darkened, said Gavin, by the position of the Labor Party, which may come to power in the next general election.

The former ambassador termed de Gaulle "a very warm man," quite unlike his public image. "He is very frank, a man who likes to talk facts, and he is quite aware that his country had been at war for two entire decades."