The Symphonie Fantastique was sub-titled 'Episode in the life of an artist,' and it deals autobiographically with Berlioz's overwhelming infatuation with an Irish actress, Harriet Smithson. Another major influence on the symphony was Berlioz's reading of Thomas de Quincey's Confessions of an English Opium Eater. This may well have introduced a certain nightmarish character into his dreams of his beloved. She is represented by a musical 'idee fixe' which occurs in many different guises throughout the symphony and which provides a unifying element. Each of the work's five movements describes different aspects of the composer's passion, from the romantic and reflective to the garish and vulgar. The Symphonie Fantastique is a supreme example of the romantic imagination in action.