Abstract
This chapter discusses the ethical theories of Cynics and Stoics. Cynicism traces its origins to Diogenes of Sinope, the most colourful and outrageous of all such founders of philosophical movements. The core Cynic doctrines articulate the principles embodied in Diogenes' way of life. The central theme is that of following nature, understood as leading a life of extreme primitiveness or self-chosen bestiality. Stoicism offers an alternative to Aristotle, who has been the main Classical source of inspiration for those evolving modern versions of virtue ethics. A striking feature of Stoic ethical theory lies in its combination of radical moral rigour or aspiration and a strongly naturalistic outlook.