Sweden may be seen as a Protestant nation of great engineers and entrepreneurs, but the nation's spiritual life has long been governed by a less official current, visible in its art and literature. Mysticism and esoteric speculation runs through the writings of some of Sweden's most important figures, from the 18th-century scientist, theologian and philosopher Emanuel Swedenborg to the turn of the 20th-century with August Strindberg, known as a novelist and playwright, but who was also involved in alchemic