Mysticism is "a constellation of distinctive practices, discourses, texts, institutions, traditions, and experiences aimed at human transformation, variously defined in different traditions."The term "mysticism" has Western origins, with various, historically determined meanings. Derived from the Greek μυω, meaning "to conceal", it referred to the biblical, the liturgical and the spiritual or contemplative dimensions in early and medieval Christianity, and became associated with "extraordinary experiences and states of mind" in the early modern period.

In modern times, "mysticism" has acquired a limited definition, but a broad application, as meaning the aim at the "union with the Absolute, the Infinite, or God". This limited definition has been applied to include a worldwide range of religious traditions and practices.

Since the 1960s, a scholarly debate has been ongoing in the scientific research of "mystical experiences" between perennial and constructionist approaches.