Marius the Epicurean: his sensations and ideas is a historical and philosophical novel by Walter Pater (his only completed full-length fiction), written between 1881 and 1884, published in 1885 and set in 161–177 AD, in the Rome of the Antonines. It explores the intellectual development of its protagonist, a young Roman of integrity, in his pursuit of a congenial religion or philosophy at a time of change and uncertainty that Pater likened to his own era. The narration is third-person, slanted from Marius's point of view, added to which are various interpolated discourses, ranging from adaptations of classical and early Christian writings to Marius’s diary and authorial comment.