The psychologist Edwin G. Boring preferred 'current of belief' as the English expression for the German word Zeitgeist, used by Goethe in 1827 to describe what comes together in the minds of many 'neither by agreement nor by self-determined under the multiplicity of climates of opinion.' That current runs above the multiple conversations conducted about how to interpret the past, how to assess the present, and how to predict and prepare for the future. For more than a century, social science has participated in all of these conversations, informing the climates of opinion that shape society, culture, and politics. Writing on the relationship between public opinion and 'representative government, the historian Lewis Namier asked, 'Where is it to be found? And how is it to be ascertained? How many people hold clear articulate views even about the most important national concerns? And if their views are original and well-grounded, what chance is there of their being representative?' Social-scientific method has improved our numerical understanding of 'public opinion,' but it is the unique responsibility of social scientists to inform. that opinion, whether it is representative or not. Namier understood that public opinion, the currents of belief, the Zeitgeist were capable of humbling the powerful: 'There is such a thing as a logic of ideas, and ideas, when looked at from a distance, seem to have an independent life and existence of their own their 'logic' is the outcome of the slow, hardly conscious thinking of the masses, very primitive, simplified in the process of accumulation, and in its mass advance deprived of all individual features, like the pebbles in a river-bed. And there is such a thing as a mental atmosphere, which at times becomes so all-pervading that hardly anyone can withdraw himself from its influence.' For example, political assumptions about the role of government, however different they may be, have a familiar ideological stability about them, even as numerous struggles persist over government's function in maintaining public order and in rectifying injustice. Political liberalism, expressed as a defense of the welfare state, gave welfare policy a popularly good name for more than a half century. Social security, medicare, and mortgage deductions have all contributed to maintaining a middle class according to liberal principles of social welfare. Libertarian sentimentalists may balk at( 回避，畏缩不前)the negative externalities created by such long-term, good intentions as keeping the elderly out of poverty, if not out of nursing homes, but it seems unlikely in the short term, at least, that any substantial social, religious, or political movement of self-respect will emerge among the classes presently benefiting the most from the largesse (赏赐物) they are responsible for creating. Social-scientific understanding is distinct from political conviction, but the two have a long relationship that seems likely to continue, regardless of ideological cross-currents. Such crosscurrents of confidence, as it were, have in recent decades defined the battles over the legacy of the most tragic consequences, however unintended, of social welfare policy: in the case of the poor, the role of government gave 'welfare' a bad name. As that welfare policy transfers to individual states, social scientists, whatever their methodologies, have a responsibility to continue informing public understanding about the conditions of entire populations and sub-groups within those populations. They will continue to face the difficulty of how to acknowledge the limits of their knowledge at any moment in time. The best title for this passage might be ______.