Which is worse, the Kremlin is increasingly asking itself: knowing what our people think, or notm knowing what they think? At issue is the long-battered discipline of Soviet sociology, gagged under Stalin, revived under Khrushchev, subjected to more subtle ideological dentistry for most of Leonid Brezhnev's rule. A few top officials backed a small revival of opinion research in Mr. Brezhnev's last years. He himself said one lesson of the Polish crisis was the need to pay ''close heed'' to public opinion.
Early signs in the post-Brezhnev era - including the naming of a new chief sociologist - suggest the Yuri Andropov regime may try to ease some restraints on sociology, or at least on opinion polling. The evidence also suggests continued concern not to let the process go too far, lest it challenge the tenets of Soviet Marxism. One constant in the Kremlin attitude toward opinion study - that it should avoid questioning the basics of the political system - is sure to survive.
A key area of fresh official interest in sociology is ''operational'' - seeking less to decipher society than use opinion studies to test or predict the effectiveness of official policies or propaganda. ''Propaganda sociology'' is the field of the new head of the sociological establishment.
Yet beyond this, a theory of ''contradictions'' in Soviet society has lately been aired by Mr. Andropov and other officials. It says that while the Soviet Union has reached classlessness, there persist less basic frictions between individuals or small groups and society as a whole. These are said to merit study.
The theory rejects what Mr. Andropov terms ''Western sociology'' but may conceivably help researchers find proper ideological gift-wrapping for wider sociological research.
The latest drama for Soviet sociology surfaced at a June session of the Communist Party Central Committee on ideology and propaganda. Both Mr. Andropov and Politburo ideology specialist Konstantin Chernenko suggested a more active role for sociology.
Mr. Chernenko seemed to link this to concern over the attitudes of some citizens on issues like religion, consumer goods, or alcohol. He called for an ''all-round study'' of Soviet society's ''non-antagonistic contradictions,'' but he added that this must be ''guided'' by ''revolutionary theory.''
A final resolution called for establishment of a ''center for the study of public opinion'' at Moscow's Institute of Sociological Research.
Shortly beforehand, the Monitor has learned, the two top men in the official sociological hierarchy had been replaced by a single, younger figure. He is Vilyen Ivanov, 50, who now heads both the Soviet Sociology Association and the ISR.
Mr. Ivanov previously ran a ''closed department'' of the ISR, evidently handling some of the many opinion studies meant for private official use.
His own field is a distinctly Soviet animal he terms ''the sociology of propaganda.'' This ''analyzes the effectiveness of . . . propaganda,'' he explains in the latest issue of the institute's journal.
The article, perhaps something of an inaugural address, implies he may foster some measured expansion of sociological inquiry. His comments on propaganda are mild, making clear, among other things, that most citizens are immune to ''anti-Soviet propaganda.''
Yet he also notes that one cannot investigate effectiveness of propaganda ''without taking account of the specifics of the social way of life of various classes (groups, strata, collectives). . . .'' He adds that sociology's tools should include opinion polls and social ''models.''
Throughout Soviet history, the ideological establishment has generally vetoed anything resembling Western-style sociology. The ideologists argue sociology simply has no place, that the ''laws'' of Marxism explain all social phenomena.
Only after Stalin did sociology briefly flourish. In the 1960s a group of young economists and political scientists - enticed primarily, a former member says, by the very ''Western'' sociology the ideological establishment most mistrusts - gravitated to a fledgling Institute of Concrete Social Research.
By the early 1970s, the institute lost out to Kremlin ideological arbiters, got a new director, was thoroughly purged, and had the word ''concrete'' taken from its name. Thus, the present ISR. For some years, the former sociologist maintains, even ''closed'' studies for the leadership were often laundered by their docile or jittery authors.
Only in the late 1970s was there some visible revival of inquiry into potentially tricky areas such as generational change, sexual mores, attitudes toward crime. The revival seemed linked in part to support from three influential party figures for expanded opinion polling.
One was Mr. Chernenko. A second was Georgian party chief Eduard Shevardnadze. The third was Geidar Aliyev, then party head in Azerbaijan, but since elevated to first deputy Soviet premier and member of the national party Politburo.
Even then, sociology had to contend with constraints. For example, when Western reporters last year highlighted various articles on sexual mores, staffers on the ISR journal were told to go easy on such material.
Mr. Andropov, writing in the Communist Party ideological journal this past February, said:
''Sometimes one hears claims [that] new phenomena of social life 'don't fit' the concepts of Marxism-Leninism, that it is undergoing a 'crisis,' that it needs to be 'reinvigorated' with an infusion of ideas drawn from Western sociology, philosophy, or political science.''
Rejecting this, he said analysts should ''apply the tremendous intellectual power'' of Marxist-Leninism to ''concrete study of specific questions.''