Esotericism refers to the doctrines or practices of esoteric knowledge, or otherwise the quality or state of being described as esoteric, or obscure.[LINK: http://www.webster.com/dictionary/esotericism] Merriam-Webster Online Dictionary : esotericism Esoteric knowledge is that which is specialized or advanced in nature, available only to a narrow circle of "enlightened", "initiated", or highly educated people.[LINK: http://www.webster.com/dictionary/esoteric] Merriam-Webster Online Dictionary : esoteric Items pertaining to esotericism may be known as esoterica.[LINK: http://www.webster.com/dictionary/esoterica] Merriam-Webster Online Dictionary : esoterica Some interpretations of esotericism are very broad and include even unconventional and non-scientific belief systems, typically as contrasted with the "scientific" or "traditional