John M. Doris has been a leading proponent of interdisciplinary approaches to moral psychology since their rise to prominence in the 1990's. His work has helped foster a methodological reorientation in the field, and has had a transformative effect on the way philosophers approach questions of character, virtue, and agency. This volume collects a selection of Doris' work spanning 20 years, focusing on the ways in which human personality orders (and fails to order) moral cognition and behaviour. It also presents two new chapters, which together form an in-depth assessment of recent developments in the moral psychology of character, as well as a closing commentary outlining methodological recommendations for those aspiring to do empirically responsible moral psychology. Together, these works present a distinctive vision of moral psychology which will engage both philosophers and psychologists.