Esotericism or Esoterism signifies the holding of esoteric opinions or beliefs, that is, ideas preserved or understood by a small group or those specially initiated, or of rare or unusual interest. The term derives from the Greek ἐσωτερικός (esôterikos), a compound of ἔσω (esô): “within“, thus “pertaining to the more inward”, mystic. Its antonym is “exoteric“.
The term can also refer to the academic study of esoteric religious movements and philosophies, or more generally of alternative or marginalized religious movements or philosophies whose proponents distinguish their beliefs, practices, and experiences from mainstream institutionalized traditions.
Examples of esoteric religious movements and philosophies include Alchemy, Astrology, Anthroposophy, early Christian mysticism, Magic, Mesmerism, Rosicrucianism, Swedenborgianism, Spiritualism, the Christian Theosophy of Jacob Böhme and his followers, and the Theosophical currents associated with Helena Blavatsky and her followers. There are competing views regarding the common traits uniting these currents, not all of which involve “inwardness”, mystery, occultism or secrecy as a crucial trait.
Since esotericism is not a single tradition but a vast array of often unrelated figures and movements, there is no single historical thread underlying them all. The developments that one might wish to emphasize in drawing up a history of esotericism furthermore depends on whether esotericism in the dictionary (non-scholarly) or the scholarly sense is intended.
Several historically attested religions emphasize secret or hidden knowledge, and are thus esoteric in the dictionary sense, without necessarily being esoteric movements in the scholarly sense of the word. Thus, the Roman Empire had several mystery religions which emphasized initiation. Some saw Christianity, with its ritual of baptism, as a mystery religion. None of these are “esoteric” in the scholarly sense. The terms “Gnosticism” and “Gnosis” refer to a family of religious movements which claimed to possess secret knowledge (gnosis). Another important movement from the ancient world was Hermeticism or Hermetism. Both of these are often seen as precursors to esoteric movements in the scholarly sense of the word.
Non-Western traditions can also display the characteristics of esoteric movements. The Ismaili Muslims also stress a distinction between the inner and the outer. It is believed that spiritual salvation is attained by receiving the ‘Nur’ (light) through the “esoteric”, that is, spiritual search for enlightenment. Ismaili Islam also has some of the characteristics associated with esotericism as defined by Faivre, e.g. the belief in an intermediate spiritual sphere mediating between humans and the divine. Esoteric movements in Buddhism, which fall under the general category of Vajrayana Buddhism, employ esoteric training into Buddha’s teachings, through use of symbols, mantra and hand-gestures, or mudra. Initiation rituals are typically given to students as they progress along these paths, and care is taken not to discuss specific rituals to those lacking the right empowerment.
In order to distinguish esoteric currents based primarily on sources from late Antiquity and the European Middle Ages, from e.g. Islamic or Jewish currents with similar features, the more precise term “Western esotericism” is often employed.
Western esoteric movements in the scholarly sense thus have roots in Antiquity and the Middle Ages. A major phase in the development of Western esotericism begins in the Renaissance, partly as the result of various attempts to revive such earlier movements. During the Italian Renaissance, for example, translators such as Ficino and Pico della Mirandola turned their attention to the classical literature of Neoplatonism, and what was thought to be the pre-Mosaic tradition of Hermeticism. Other pursuits of Antiquity that entered into the mix of esoteric speculation were astrology and alchemy. Beside such revived currents from late Antiquity, a second major source of esoteric speculation is the Kabbalah, which was lifted out of its Jewish context and adapted to a Christian framework by people such as Johannes Reuchlin. Outside the Italian Renaissance, yet another major current of esotericism was initiated by Paracelsus, who combined alchemical and astrological themes (among others) into a complex body of doctrines.
In the early 17th century, esotericism is represented by currents such as Christian theosophy and Rosicrucianism. A century later, esoteric ideas entered various strands of Freemasonry. Later in the 18th century, as well as in the early 19th century, the diffuse movement known as Mesmerism became a major expression of esotericism. In the 19th century, esotericism is also represented by certain aspects of the philosophy, literature and science associated with Romanticism, by spiritualism, and by a notable French wave of occultism.
The major exponent of esotericism in the latter part of the 19th century is the Theosophy of H. P. Blavatsky, not to be confused with the Christian Theosophy mentioned above. In the 20th century, Theosophy was reformulated by Annie Besant, Charles Webster Leadbeater, Alice Bailey, Rudolf Steiner and many others, and became the source for a whole range of post-theosophical movements such as The Summit Lighthouse. A particularly successful post-theosophical movement is Anthroposophy, a synthesis of occultist, Christian and Neoplatonic ideas with Western esoteric concepts as formulated in the wake of Theosophy. Anthroposophy, which was founded by Rudolf Steiner in the early part of the 20th century, includes esoteric versions of education, agriculture, and medicine.
Yet another notable esoteric strain stems from the teachings of G. I. Gurdjieff and P. D. Ouspensky.
Theosophy is also considered a major influence on the many less institutionally organized varieties of esotericism in metaphysical milieus, “Ascended Master Activities”, and within the New Age.
Finally, it can be noted that Carl Gustav Jung can be seen as an exponent of esotericism: his writings concern esoteric subject matter such as alchemy, and rephrased the concept of correspondences in a modern, psychologizing terminology in his theory of synchronicity.