Lucius Annaeus Seneca the Younger was a major philosophical figure of the Roman Imperial Period. As a Stoic philosopher writing in Latin, Seneca and early Roman Emperor Marcus Aurelius, among others, made lasting contributions to Stoicism.
Meditations by Marcus Aurelius has long been one of my favorite books, and I often quote passages from his meant-to-be private diary at AA meetings. I believe Stoicism works well with the principles of Alcoholics Anonymous, and I often encourage sponsees of mine and members to read Meditations alongside the AA Big Book.