Emanuel Swedenborg (born Emanuel Swedberg; February 8, 1688–March 29, 1772) was a Swedish scientist, philosopher, Christian mystic, and theologian. Swedenborg had a prolific career as an inventor and scientist. At the age of fifty-six he entered into a spiritual phase in which he experienced dreams and visions. This culminated in a spiritual awakening, where he claimed he was appointed by the Lord to write a heavenly doctrine to reform Christianity. He claimed that the Lord had opened his eyes, so that from then on he could freely visit heaven and hell, and talk with angels, demons, and other spirits. For the remaining 28 years of his life, he wrote and published 18 theological works, of which the best known was Heaven and Hell (1758), and several unpublished theological works.