“If one does not know to which port one is sailing, no wind is favorable.” - Lucius Annaeus Seneca.
Letters from a Stoic still holds the power to enthrall. The epistles were written by Seneca at the end of his life, during his retirement, after he had worked for the Emperor Nero for fifteen years. They are addressed to Lucilius, the then procurator of Sicily, although he is known only through Seneca's writings. Whether or not Seneca and Lucilius actually corresponded, or whether in fact Seneca created the work as a form of fiction, is not clear from the historical record.
This is the third volume of the Letters, Epistles Letter XCIII - CXXIV.
Lucius Annaeus Seneca (often known simply as Seneca or Seneca the Younger); ca. 4 BC – 65 AD) was a Roman Stoic philosopher, statesman, and dramatist of the Silver Age of Latin literature. He was tutor and later advisor to emperor Nero, who later forced him to commit suicide for alleged complicity in the Pisonian conspiracy to have him assassinated.
É um bom livro com boas dicas sobre o estoicismo, mas entre os 3 esse é o mais fraco, no final dele eu já estava entediado...
Caso você não tenha muito tempo disponível e queira um bom livro sobre estoicismo leia o volume 1, ele é excelente e já vai te dar uma base ótima sobre essa filosofia.