On kindness, by Lucius Annaeus Seneca

Seneca (4 BC – 65 AD) is one of the most famous ancient Greek philosophers despite belonging to an extended philosophical trend filled with prominent figures over three centuries before him, which is the Stoic trend; that trend was founded by Zeno under the name "The Stoa" around 307 BC. Usually, historians divide the philosophers of this trend or school into three eras: 1. The ancient era or the ancient Stoicism: which extends over the 4th and 3rd centuries BC, and its most prominent figures are three: Zeno the founder, Cleanthes, and Chrysippus, who is considered the second founder of the school. 2. Middle Stoicism: extending over the 2nd and 1st centuries BC, and its most prominent figures are Panaetius, Posidonius, and Ptolemy, the last of whom was famous for his encyclopedic work to the extent that some historians compared him to Aristotle in the abundance and diversity of his intellectual output. Stoicism in this era succeeded in reconciling the teachings of ancient Stoicism with those of both Plato and Aristotle, attracting many who studied at the Academy, the Platonic school, and the Peripatetic school, the Aristotelian school. 3. Late or modern Stoicism, or Roman Stoicism: because political, military, and intellectual dominance had shifted to Rome at this time, and this late era of Stoicism extended for several centuries from the 1st century AD, although its greatest philosophers—Seneca, Epictetus, and Marcus Aurelius—lived between the 1st BC and the 2nd AD, with the last of them, Emperor Marcus Aurelius, dying in 180 AD.