IN this brief concluding essay, our intention is not so much to summarize as to distill. The individual articles in this symposium are, after all, themselves summaries. Each provides a sketch of a range of complicated policy problems, and of a tangled variety of half-coordinated attempts to solve them. We can hope to extract two kinds of lessons from this history. One has to do with the general process of social reform in a middle-class democracy, or at least in this middle-class democracy. A second has to do with the specific legislative programs that made up the Great Society.  We do not have much to add to what our colleagues have said about the nature of particular problems and the successes and failures of individual programs in responding to them, so we will concentrate our attention on the more general implications of recent experience for social intervention and social reform.