What kind of people make good scientists? What personal qualities do scholars say their peers should exhibit? And how do they express these expectations? This article explores these issues by mapping the kinds of virtues discussed by American scientists between 1945 and 2000. Our wide-ranging comparative analysis maps scientific virtue talk across three distinct disciplines - physics, psychology, and history - and across sources that typify those disciplines' scientific ethos - introductory textbooks, book reviews, and codes of ethics. We find that, when inducting students into a discipline, evaluating peers, or codifying their professional standards, postwar American scientists routinely named virtues like carefulness, objectivity, and honesty. They applied such virtues not only directly to scholars' characters, minds, and attitudes (thereby equating virtues with personal qualities), but also to their methods, modes of reasoning, and working habits (in the form of what we call virtue-qualifiers). Strikingly, we find that physicists, psychologists, and historians drew upon largely similar repertoires of virtue. For all of them, scientific work required carefulness, thoroughness, and accuracy. Not all virtues, however, were equally important in all disciplines (notably objectivity), nor did each ethos-forming genre place equal emphasis on the directly personal nature of such virtues. All in all, our research establishes an extended framework for understanding the ways virtues remained present in postwar American scientific discourse writ large.
Keywords: epistemic virtues; history; integrity; physics; psychology; scientific attitude; virtue.