Jung postulated, in addition to the personal unconscious (roughly adopting Freud's concept), the collective unconscious, which is the repository of human experience and which contains "archetypes" (i.e. basic images that are universal in that they recur regardless of culture). The irruption of these images from the unconscious into the realm of consciousness he viewed as the basis of religious experience and often of artistic creativity. Some of Jung's writings have been devoted to elucidating some of the archetypal symbols, and include his work in comparative mythology.