This collection of essays showcases the most important and influential philosophical works of the ancient and medieval period, roughly from 600 BC to AD 1600. Each chapter takes a particular work of philosophy and discusses its proponent, its content and central arguments. These are: Plato's Republic; Aristotle' Nichomachean Ethics; Lucretius' On the Nature of the Universe; Sextus Emperiicus' Outlines of Pyrrhonism; Plotinus' The Enneads; Augustine's City of God; Anselm's Proslogion; Aquinas' Summa Theologia; Duns Scotus' Ordinatio; William of Ockham's Summa Logicae .