Epicurus posited a materialistic physics, in which pleasure, by which he meant freedom from pain, is the highest good. Serenity, the harmony of mind and body, is best achieved, through virtue and simple living. In addition to the Principal Doctrines , included here is the essay Epicureanism by William De Witt Hyde discussing Epicurus and his philosophy, an Epicurus biography by Charles Bradlaugh and an image gallery.