 When considering the doctrines of the Stoics, it is important to remember that they think of philosophy not as an interesting pastime or even a particular body of knowledge, but as a way of life. They define philosophy as a kind of practice or exercise (askêsis) in the expertise concerning what is beneficial (Aetius, 26A). Once we come to know what we and the world around us are really like, and especially the nature of value, we will be utterly transformed. This therapeutic aspect is common to their main competitors, the Epicureans, and perhaps helps to explain why both were eventually eclipsed by Christianity. The Meditations of Marcus Aurelius provide a fascinating picture of a would-be Stoic sage at work on himself. The book, also called To Himself, is the emperor’s diary. In it, he not only reminds himself of the content of important Stoic teaching but also reproaches himself when he realises that he has failed to incorporate this teaching into his life in some particular instance. Today many people still turn to Stoicism as a form of psychological discipline. Stoicism has never been ‘purely academic’ and modern adaptations of Stoic thought seek to carry on this tradition of self-transformation. One of the most influential modern interpretations of means through which the Stoic philosophizing accomplished such a transformation introduces the notion of spiritual exercises. Hadot (1998) provides a reading of Marcus Aurelius’ Meditations as a set of such exercises. For a more general treatment covering Stoic philosophy as a whole, see Sellars (2013). For a recent discussion of the entire question of philosophy as a way – or rather as many ways – of life in antiquity, see Cooper 2102. 