Shamanic practices, found universally across hunter-gatherer societies worldwide and throughout history, reflect fundamental neurological processes and brain structures. The shamanic paradigm—including animism, totemism, soul flight, animal spirits, and death-and-rebirth experiences—arises from innate brain modules and neurognostic structures. This universal biopsychosocial framework can bridge scientific and religious perspectives by explaining the biological underpinnings of spiritual experiences, thereby providing a basis for neurotheology and evolutionary theology.
The author argues that the Buddhist sacramental substance amrita originated in the Vedic soma, an entheogenic ritual drink. Drawing on ancient texts and archaeological evidence, the analysis contends that soma traditions did not originate with Indo-Aryan peoples but were instead obtained from the Indus Valley Civilization (IVC). Depictions of ceramic strainers associated with soma ritual resemble earlier Harappan artifacts, suggesting cultural transfer. The author further traces parallels between the Vedic myth The Churning of the Ocean and the Tibetan Buddhist text Immaculate Crystal Garland, showing that Buddhist accounts of amrita derive from earlier Sanskrit versions. Additional evidence links features of Vajrayana deities to psychoactive mushrooms such as fly agaric and Psilocybe cubensis.
Elisa Guerra Doce's book argues that contemporary debates about psychoactive substances can be informed by the wide variety of botanical substances used across human history and prehistory. Doce notes the difficulty in determining whether substances are strictly psychedelic versus psychoactive but argues that the context leads to the conclusion that uses were entheogenic. Using ethnographic analogies from the Americas, Near and Middle East, India, China, and the Classical world, Doce reviews evidence for psychoactive plant use in the Neolithic, Bronze Age, and Iron Age of Europe.