Rosicrucianism is a philosophical secret society said to have been founded in late medieval Germany by Christian Rosenkreuz. It holds a doctrine or theology 'built on esoteric truths of the ancient past', which, 'concealed from the average man, provide insight into nature, the physical universe and the spiritual realm.' Rosicrucianism is symbolized by the Rose Cross. Many esoteric societies have claimed to derive their doctrines, in whole or in part, from the original Rosicrucians (including Freemasonry). Several modern societies have been formed of the study of Rosicrucianism and allied subjects. William Walker Atkinson (1862-1932) was a prolific writer. His works treat themes related to the mental world, occultism, divination, psychic reality, and mankind's nature. They constitute a basis for what Atkinson called 'New Psychology' or 'New Thought'.