He is the author of The Art of Living: The Stoics on the Nature and Function of Philosophy, Stoicism (2006), and Hellenistic Philosophy, Lessons in Stoicism. He is one of the founder members of 'Modern Stoicism', the group behind Stoic Week and Stoicon.
For the Stoics philosophy is an art or craft analogous to medicine.
Like medicine it involves a body of complex ideas but, also like medicine, the point of learning those complex ideas is in order to achieve a very practical outcome.
That outcome, again like medicine, is therapeutic, but it is therapy for the mind rather than the body.