The chapter reviews the essentials of Seneca’s positions in moral psychology as compared to those of earlier Stoics whose works he might have studied. On the material nature of the mind (or soul); on the mechanisms of thought, belief, and action; and on the nature and management of the emotions, Seneca’s views are consonant with those of his Stoic predecessors; however, his knowledge of the system is not necessarily complete, and his emphases are sometimes different. Thus, he shows some awareness of earlier discussions of phantasia (impressions) but does not explore the topic deeply; on the other hand, he gives assent and impulse the same kind of significance in ethics as Chrysippus had. Contrary to some earlier studies, this chapter does not find Seneca to be innovative as concerns volition (voluntas) or the will. Likewise, his analysis of the emotions and of involuntary emotional response finds parallel in earlier texts. For the good emotions (eupatheiai) of the Stoic sage, he seems to know only that part of the analysis that concerns joy, to which he assigns an important role in his own ethics.

Seneca’s discussions of prose style frequently apply language of masculinity or effeminacy not only to authors but also to their works. For him, the laxness that he finds in Maecenas’s writing is a direct reflection of character flaws that he as a cisgender Roman male attributes to defective masculinity. The figure of Maecenas thus emblematizes the proverb that style mirrors conduct (talis oratio qualis vita). But there is also a philosophical underpinning to Seneca’s position. Stoic ethics attaches great importance to integrity and coherence in one’s thought, and thought, as internal speech, is closely allied to what he calls the ingenium; that is, the linguistic ability of an individual that is manifested in speech and writing. Prose style is thus understood as a reflex of character: The “manly” style is a highly structured, hypotactic style that traces connections between all elements of the thought.

In the early treatise On Anger, Seneca struggles to reconcile what he thinks is required of a therapeutic treatise with the view of emotions to which he is philosophically committed. In book 1 and the first part of book 2, he states the Stoic position with great clarity: that anger, like any emotion, consists essentially in a judgment by the rational mind; that the moment this voluntary judgment has been made, anger becomes unmanageable; that involuntary corporeal responses (pre-emotions) that occur prior to that assent are not themselves anger. Even the contested passage in De ira 2.4 can be read consistently with Stoic orthodoxy if one recognizes that the “third movement” described there is a further response that goes on beyond anger, namely the impulses of post-rational feritas as described in 2.5. Seneca’s recommendations for the management of anger in the remainder of the book mainly accord with this theoretical framework, in that they concentrate on the period before assent. At one point in book 3, however, he does offer a stratagem for managing anger in full swing, in tension with his own theoretical position.