Esotericism:

The adjective esoteric can be traced back to antiquity where Aristotle is credited with having invented it even though it was first introduced by Lucian of Samosata around 166 C. E. [1] The use of the English substantive esotericism, however, has not been traced fur¬ther back into history than 1829. [2] Scholars such as Wouter J. Hanegraaff and Antoine Faivre claim that the substantive esotericism itself was first popularized by Eliphas Levi around 1856. [3] As Antoine Faivre writes:

“Eliphas Lévi (1810-1875) is credited with the coining of this term [esotericism]. He derived it from “philosophia occulta,” in the sense promulgated by Henricus Cornelius Agrippa in De Occulta philosophia (1533), to designate a group of investigations and practices having to do with such “sciences” as astrology, magic, alchemy, and the Kabbalah.”[4]

From this we see that Eliphas Lévi brought the substantive esotericism into use as a term for which all the “sciences” as mentioned above could be classified, because, they shared something in common. As Wouter J. Hanegraaff writes:

“...he [Eliphas Lévi] introduced “esotericism” as a new term applicable to a range of phe¬nomena which had traditionally been referred to by other names. In doing so, he con¬strued what we may call an etic category. The term “esotericism” covered the traditional “occult sciences” and a wide range of historical phenomena connected or loosely associ¬ated with them.”[5]

From this we see that the concept esotericism was a term brought forth around 1856 by Eliphas Lévi in order to categorize certain phenomena or various sciences under the same class, but this does not really tell us what the concept means it only tells us that these various sciences have something in common.

If we examine the English adjective esoteric etymologically and a priori we see that the concept comes from the Greek word esoterikos where eso means inner and with the comparative suffix terikos it means inside. The original use of the concept was that of distinguishing the inner (esoteric) teachings or schools from that of the outer (exoteric) teachings or schools. However, many definitions of esotericism are at present used in different contexts, many of which stretch beyond that which is merely inner or for the initiates see especially Antoine Faivres definition as set forth in his 'Access to Western Esotericism'.

Tim Rudbøg, 2002

[1] See Wouter J. Hanegraaf, New Age Religion and Western Culture, E.J. Brill, Leiden, The Netherlands 1996, p. 384.

[2] Used by Jacques Matter in his Histoire du gnosticisme (1828).