The National Academy of Sciences at its 112th Annual Meeting on April 21, 1975, paid homage to the comparatively young National Science Foundation (NSF), in celebration of its 25th birthday. The planning that went into the symposium will become clear to the reader of these four papers, which are quite different in style and content but united by their central concern with the past and future of NSF. Detlev W. Bronk draws on the rich lode of his memory as he describes the Foundation's origins and aspirations. William A. Fowler describes by examples how the Foundation's investment in research has changed our understanding of Planet Earth, the gene, and the universe and is aiding the transfer of knowledge to an attack on environmental and social problems. Joseph B. Platt assays NSF's education programs in the light of recommendations in Dr. Vannevar Bush's report. Finally , H. Guyford Stever reflects on the directions that the Foundation may take in the years that lie ahead, during a time of growing awareness among scientists that they are also citizens and that their research often affects and is affected by individual and social values. (LS)