Sénèque
It is not that we have little time, but that we waste much.
On Anger essential
Three books addressed to his brother Novatus. Written after Caligula's death (41), exact date debated. He reports and refutes Aristotle and Theophrastus: anger is never useful.
On the Shortness of Life essential
Addressed to Paulinus, in charge of Rome's grain supply. Date debated (between 48 and 55). Life is not short: we are the ones who waste it.
On Tranquillity of Mind essential
Addressed to his friend Serenus. Chapter 1 is a letter from Serenus, describing his unrest (written by Seneca); Seneca answers from chapter 2 on. Date debated.
On the Firmness of the Wise Man
Addressed to Serenus: the wise man can receive neither injury nor insult, since nothing that is his can be taken from him. Date debated.
On the Happy Life essential
Addressed to his brother Gallio. The second half answers those who accuse the philosopher of living like a rich man. The end is lost: the text breaks off in chapter 28.
Letters to Lucilius (Moral Letters) essential
124 letters to his friend Lucilius, written in his last years. Probably composed for publication: whether they are a real correspondence is still debated. Part is lost (antiquity knew at least one more book). Our corpus contains all 124 letters.
On Providence essential
Full title: "Why misfortunes befall good men, though there is a Providence". Addressed to Lucilius. Date debated. Chapter 6 ends with a speech by God in the first person, written by Seneca.
Consolations, On Mercy, On Benefits, Natural Questions
Three consolations (to Marcia, to his mother Helvia, to Polybius), a treatise addressed to Nero on the ruler's mercy, seven books on benefits, a physics in several books. Not yet in our corpus.
Tragedies (Medea, Phaedra, Thyestes…)
The only Latin tragedies preserved in full. The attribution of two plays (Hercules on Oeta, Octavia) is disputed. Not yet in our corpus.