This chapter provides an introduction to the major figures in the history of Ancient Stoicism, and describes the sources of knowledge in Stoic philosophy. The Stoic school began a little before 300 BC, and reached the height of its theoretical elaboration in the next century. Stoic philosophers include Chyrsippus, Epictetus, Zeno of Citium (founder of the Stoic school), Cleanthes, Diogenes of Babylon, Antipater of Tarsus, and Cicero. The four sources accounting for more than half the bulk of testimony and evidence on Stoicism are: Cicero, Seneca, Epictetus, and Marcus. The most important source of biographical information about early Stoics and their philosophy is the author Diogenes Laertius.
Keywords: Ancient Stoicism, Stoic philosophy, philosophers