This paper formulates the categories of “ethics,”“self,” and “subject” for an analysis of classical rabbinic ethics centered on the text, The Fathers According to Rabbi Nathan. Early rabbis were concerned with the realms of life that today's scholars describe as ethics and self-cultivation, yet they had no overarching concepts for either the self/person or for ethics. This analysis, then, cannot rely only upon native rabbinic terminology, but also requires a careful use of contemporary categories. This paper first sets out basic features of Rabbi Nathan and presents appropriate formulations of the relevant scholarly terms. The latter sections address possibilities for employing and revising these categories in descriptive and comparative studies more broadly, first surveying relevant scholarship on Christian, Muslim, and Manichaean sources, and then turning to ancient East Asian sources with a particular focus upon passages in the Zhuangzi.