What difference does history of science make, anyway?

This essay opens up the question of what difference the history of science makes. What is the value of the history of science, beyond its role as an academic pursuit that we historians of science know and love? It introduces the set of essays that follow as explorations that grew out of a seminar on this topic and that arise from the authors' particular concerns both that historians of science do not work hard enough to make their work of value and that others do not know of the potential. That seminar, at the Marine Biological Laboratory, was funded for nineteen years by the Dibner Institute and last year by Brent Dibner. It will continue and carry such discussions forward in new ways as the Arizona State University-Marine Biological Laboratory History of Biology Seminar Series. This set of focused essays seeks to invite lively discussion and response.