The studies of mysticism have traditionally emphasized a common core centered around experiences of ego dissolution and unity. However, this focus on a central set of experiences tends to downplay the non-central aspects, resulting in a limited understanding that may not encompass many other types of extraordinary experiences. This article proposes a layered hierarchy model of mysticism, which reverts to the fundamental definition of mysticism and resonates with the Jamesian characteristics of mysticism as noetic and ineffable. Consequently, an extended definition (...) is put forth to characterize mysticism as the transcendence of perceived reality and the transformation of the perceiver. Within this proposed model, four layers of mysticism are delineated. Monistic Mysticism is characterized by the perception of oneness in all existence and the dissolution of selfhood, exemplified by perennialist mystical unity. Nondualistic Mysticism involves the recognition of a higher reality beyond the mundane world and the subjugation of the ego to an idealized divine, exemplified by religious experiences. Dualistic Mysticism encompasses a world of spirits in contrast to human reality, where the self detaches from and interacts with spiritual beings, exemplified by psychedelic experiences and spiritism. Pluralistic Mysticism entails numerous coexisting realities, and the self is understood to have many facets and boundless potentials, exemplified by psychic phenomena and non-physicalism. This expanded framework broadens the scope of mysticism and makes it a versatile tool for studying a wide range of human experiences under a unified framework. (shrink)