The moral terrain of science, the full range of ethical considerations that are part of the scientific endeavor, has not been mapped. Without such a map, we cannot examine the responsibilities of scientists to see if the institutions of science are adequately constructed. This paper attempts such a map by describing four dimensions of the terrain: (1) the bases to which scientists are responsible (scientific reasoning, the scientific community, and the broader society); (2) the nature of the responsibility (general or (...) role); (3) the level of responsibility (minimum demand or ideal); and (4) who bears the responsibility (the individual or the community). Such a map will be used to elucidate the recent debate over the publication of studies concerning H5N1 flu virus. (shrink)