We historicize the idea of “responsibility” in relation to science and technology. By charting the multiple and contested notions of responsibility that scientists have espoused from the early twentieth century to the present, we illuminate the very specific and contingent understanding of “responsibility” embodied in RRI. Scientists have used the word “responsibility” strategically, at different times and in different contexts – including the Pugwash conferences from the 1950s, and the rise of the new left in the 1970s – to project their preferred views of how science should relate to wider society. Comparing the Japan and the UK highlights both the context-specific meanings that scientists have associated with responsibility, and the way that those specific meanings have come into conversation with one another. Notably, Japanese physicists played a major role in defining scientific responsibility in the years after the second world war, not just in Japan but internationally, in their capacity as representatives of the only country to have experienced nuclear bombing. In thinking about the purpose and desirability of alternative practices for RRI, it is helpful to consider the professional and wider societal aims and implications of existing configurations and construals of “responsible” research and innovation – including how those configurations may shield scientists from certain kinds of responsibility while embracing others. Showing how the idea of “responsibility” has been deployed in the past provides a means of historicizing, relativizing and thereby evaluating how current claims to scientific responsibility may be configured in different contexts.