Ethics in science and technology is frequently viewed in terms of critically important values and processes to be upheld in university research. As the research enterprise has become larger, more global, faster, more complex, and associated with valuable intellectual property, a commitment to scientific integrity has become more important than ever. At a more macroscopic level, scientific knowledge is increasingly critical to major public and political decisions, e.g. about global warming, embryonic stem cells, privacy of digital communications, nanotechnology, and genetically modified foods. In this lecture I will examine three past successes as case studies -- Recombinant DNA, phasing out of Ozone-depleting chemicals, and deployment of the World Wide Web. None of these map directly onto today’s issues, but they offer hints about better ways of proceeding.