Raison d'être is a Swedish industrial ambient music project formed by Peter Andersson. The name of the band was taken from a sentence in a book by Carl Gustav Jung: "the individuation is the raison d’être of the self". Dark ambient atmospheres, drone elements, industrial sounds, ecclesiastical hymns are all blended together to constitute the music of Raison d'être. Deeply influenced by the writings of C.G.Jung, Raison d'être explores the depths of human psyche providing soundtracks for inner voyages towards the Tragic.

The music produced by Raison d'être is variously dark ambient and soundscape in nature. For example, synthesizers might play a droning melody over the sound of metal scraping together. Andersson often mixes tapes of Gregorian chant with his own keyboard and percussion playing.