The essay "Of Peace of Mind" was written as a means of guidance for all those who wish to dedicate themselves to moral improvement. Seneca presents the stoic doctrine's response to help us overcome the torments caused by human fears and desires and achieve tranquility, the ideal state of serenity experienced fully and permanently by the ideal stoic sage. Seneca's philosophical lecture is used not as a strictly intellectual activity, but as a means to stimulate in the readers an inner disposition that can result in the practice of positive conducts in line with the stoic doctrine, of which Seneca was an important proponent.
Of Peace of Mind begins with a letter from Annaeus Serenus to his friend Seneca, asking for advice and saying that he feels he has a good command over some of his vices but not over others, and as a result his soul has no tranquility. He says "I am neither ill nor well" and realizes that his judgment on his own affairs is distorted by personal prejudices. Serenus lists his problems: doubt in the face of the desire for goods and physical pleasures; alternation between the desire for social action and recollection into studies and an ethical and aesthetic dilemma concerning the search for fame. After presenting the symptoms, making use of the patient's image before the doctor, Serenus asks for the diagnosis and remedy: "I beg you, therefore, if you have any remedy by which you could stop this vacillation of mine, to deem me worthy to owe my peace of mind to you".
For the modern reader, this short, powerful work offers insight into how to think like a Stoic.
