Stoic Six Pack 5 - The Cynics presents the key primary sources of this ancient philosophy, as well as secondary material to provide insight and understanding: An Introduction to Cynic Philosophy by John MacCunn, The Moral Sayings of Publius Syrus, a Roman Slave by Publius Syrus, Life of Antisthenes by Diogenes Laertius, Book IV of The Symposium by Xenophon, Life of Diogenes by Diogenes Laertius and Life of Crates by Diogenes Laertius.