<p>Philosophers provide excellent resources for developing a science of virtues, and an interdisciplinary collaboration between philosophers and psychologists seems ideal. This suggestion is not new, but there has been little guidance for psychologists about how philosophical work can be useful in developing a science of virtue. This article provides some guidance by dividing the contributions of philosophers into three categories. First, many philosophers provide theories of virtue’s nature or value, but these are generally not useful for psychological scientists and can be safely ignored. Second, awareness of the range of philosophic positions can enable scientists to recognize contentious theoretical assumptions that they are making. Psychologists need not try to resolve these debates; they can choose to only identify which position(s) they are taking. Third, awareness of the range of philosophic positions and the competing conceptual analyses of various virtue concepts and traits can help psychologists to identify and test new empirical hypotheses.</p>