 Kabbalah is considered by its followers as a necessary part of the study of Torah – the study of Torah (the "Tanakh" and rabbinic literature) being an inherent duty of observant Jews.Modern academic-historical study of Jewish mysticism reserves the term "kabbalah" to designate the particular, distinctive doctrines that textually emerged fully expressed in the Middle Ages, as distinct from the earlier Merkabah mystical concepts and methods.According to this descriptive categorisation, both versions of Kabbalistic theory, the medieval-Zoharic and the early-modern Lurianic Kabbalah together comprise the "Theosophical" tradition in Kabbalah, while the "Meditative-Ecstatic Kabbalah" incorporates a parallel inter-related Medieval tradition.