The eight-circuit model of consciousness is a holistic model originally described by Timothy Leary, later expanded on by Robert Anton Wilson and Antero Alli, that suggests "eight periods [circuits] and twenty-four stages of neurological evolution". This model has been described as a potential route towards reconciling different interpretations of what it means to be a human being. The eight circuits, or eight systems or "brains", as referred by other authors, operate within the human nervous system. Each corresponds to its own imprint and subjective experience of reality. Leary and Alli include three stages for each circuit that details developmental points for each level of consciousness. Bringing the Eastern spiritual traditions, which perceive all objects and phenomena as various interrelated aspects of a single supreme reality, transpersonal psychology and modern sciences together, contemporary philosophers are able to design and develop a new approach to a human that will bridge the gap between different interpretations of a human being. Overview The first four circuits concern themselves with life on Earth, and the survival of the human species. The last four circuits are post-terrestrial, and concern themselves with the evolution of the human species as represented by so-called altered states of consciousness, enlightenment, mystical experiences, psychedelic states of mind, and psychic abilities. The proposal suggests that these altered states of consciousness are recently realized, but not widely utilized. Leary described the first four as "larval circuits", necessary for surviving and functioning in a terrestrial human society, and proposed that the post terrestrial circuits will be useful for future humans who, through a predetermined script, continue to act on their urge to migrate to outer space and live extra-terrestrially. Leary, Wilson, and Alli have written about the idea in-depth, and have explored and attempted to define how each circuit operates, both in the lives of individual people and in societies and civilizations. The term "circuit" is equated to a metaphor of the brain being computer hardware, and the wiring of the brain as circuitry. The comparison of the brain to computer hardware and wiring has been replaced with models describing the different functions of brain networks and how they interact with each other. Leary used the eight circuits along with recapitulation theory to explain the evolution of the human species, the personal development of an individual, and the biological evolution of all life. The Eight Circuits Each circuit listed has each name from Leary's