 Seneca’s writings usually have an addressee—someone who is plagued by a ‘sickness of the soul’ (On Peace of Mind begins with a full diagnosis of the addressee’s state of mind—first by the patient, and then by the insightful therapist Seneca). Seneca steps back from a format in which a philosopher justifies a theory in a step-by-step argument (Long 2003, 204; on the question of why Seneca chooses to write letters, see Inwood 2007, xiv-xv). Discussion proceeds from a (perhaps merely presumed) situation in the addressee’s life, meandering back and forth between more general and more specific considerations, arguments, side-issues, and sometimes consolation (see Wildberger 2020 for the view that Seneca’s Letters involve the creation of a persona who, over the course of the Letters, gains increasing interest in technical questions in philosophy). This engaging style views the reader as a participant in philosophical thought (Roller 2015; Schafer 2011). Seneca thinks that in order to benefit from philosophy, one cannot passively adopt insights. One must appropriate them as an active reader, thinking through the issues for oneself, so as then to genuinely assent to them (Letter 84.5–10; Wildberger 2006).