Helena Blavatsky in the context of "Magick (Book 4)"

The occult (from Latin occultus 'hidden, secret') is a category of esoteric or supernatural beliefs and practices which generally fall outside the scope of organized religion and science, encompassing phenomena involving a 'hidden' or 'secret' agency, such as magic and mysticism. It can also refer to paranormal ideas such as extra-sensory perception and parapsychology.

The term occult sciences was used in 16th-century Europe to refer to astrology, alchemy, and natural magic. The term occultism emerged in 19th-century France, among figures such as Antoine Court de Gébelin. It came to be associated with various French esoteric groups connected to Éliphas Lévi and Papus, and in 1875 was introduced into the English language by the esotericist Helena Blavatsky.

Neo-Theosophy is a term, originally derogatory, used by the followers of Helena Blavatsky to denominate the system of Theosophical ideas expounded by Annie Besant and Charles Webster Leadbeater following the death of Madame Blavatsky in 1891. This material differed in major respects from Blavatsky's original presentation, but it is accepted as genuinely Theosophical by many Theosophists around the world.

Main innovations of post-Blavatsky Theosophy as expounded by Besant and Leadbeater were the focus on exploring past lives and the astral plane using clairvoyance, the promotion of the young Indian boy Krishnamurti as the vehicle of the coming "World Teacher" and the introduction of Catholicism and its religious rituals in the form of the Liberal Catholic Church.

Ignatius Loyola Donnelly (November 3, 1831 – January 1, 1901) was an American Congressman, populist writer, and pseudoscientist. He is known primarily now for his fringe theories concerning Atlantis, Catastrophism (especially the idea of an ancient impact event affecting ancient civilizations), and Shakespearean authorship. These works are widely regarded as examples of pseudoscience and pseudohistory. Donnelly's work corresponds to the writings of late-19th and early-20th century figures such as Helena Blavatsky, Rudolf Steiner, and James Churchward.

Theosophy is a religious movement established in the United States in the late 19th century. Founded primarily by the Russian Helena Blavatsky and based largely on her writings, it draws heavily from both older European philosophies such as Neoplatonism and Indian religions such as Hinduism and Buddhism. Although many adherents maintain that Theosophy is not a religion, it is variably categorized by religious scholars as both a new religious movement and a form of occultism from within Western esotericism.

As presented by Blavatsky, Theosophy teaches that there is an ancient and secretive brotherhood of spiritual adepts known as the Masters, who are found around the world but primarily centered in Tibet. These Masters were alleged by Blavatsky to have cultivated great wisdom and supernatural powers, and Theosophists believe they initiated the modern Theosophical movement through disseminating their teachings via Blavatsky. Theosophists believe that these Masters are attempting to revive knowledge of an ancient religion once found around the world that will again come to eclipse existing world religions. Theosophy holds a monist position that there exists a single divine Absolute and articulates an emanationist cosmology in which the universe is perceived as outward reflections from this Absolute. The purpose of human life is spiritual emancipation and the human soul undergoes reincarnation upon bodily death according to a process of karma. Universal brotherhood and social improvement are guiding principles, although there is no particular ethical framework.

The Theosophical Society is the organizational body of Theosophy, an esoteric new religious movement. It was founded in New York City, United States in 1875. Among its founders were Helena Blavatsky, a Russian mystic and the principal thinker of the Theosophy movement, and Henry Steel Olcott, the society's first president. It draws upon a wide array of influences, among them older European philosophies and movements such as Neoplatonism and occultism, as well as parts of eastern religious traditions such as Hinduism and Buddhism.

The founders described "Theosophy" as the synthesis of science, religion and philosophy. It notes that the purpose of human life is spiritual emancipation and the human soul undergoes reincarnation upon bodily death according to a process of karma, referring to the principles from Indian religions. Around 1880, Blavatsky and Olcott moved to India, and the organization split into the Theosophical Society (Adyar, India) and the Theosophical Society (Pasadena, California).