In this study, we explore the etymology and history of "agency," link it with relational psychoanalytic literature, and examine how it can be understood within Lacanian psychoanalytic theory and practice. Building on its history, we find that "agency" embodies a binary distinction between the person as an actor, on the one hand, and as a being who is subject to determining structures, on the other. This binary approach, however, limits the debate concerning agency. Arendt's concept of "action," which builds on the same etymological stem as "agency" (i.e., "agere"), allows for nuance in the concept and moves it beyond its otherwise binary understanding. Through this conceptual work, we draw three conclusions regarding patient agency: (a) agency can only come about in relation to others; (b) initiating a new beginning in speech acts and actions already implies agency; and (c) one must be willing to take responsibility for the consequences of one's actions to be able to feel agentic. Lastly, we relate these three conclusions to Lacanian psychoanalysis, in particular to the notions of alienation and separation, full speech, and guilt.