All is One

All is One is a phrase for the felt subsuming of self and world into a single whole, a central feature of many accounts of mystical experience. The book treats it not as proof of a supernatural reality but as an experience whose force, interpretation, and cultural meaning can diverge: unity may feel revelatory to one person and disturbing to another, while the practices and histories associated with it resist reduction to a universal spiritual formula.

Unity as an experience, not a verdict

In the Mystical Experience Questionnaire, the author found that the item concerning an experience of All is One was easy to endorse, but not as a positive revelation. During the toad journey, the mind storm had felt so all-consuming that differentiation and multiplicity were precisely what the author missed. The same questionnaire yielded a score of sixty-one, just above the threshold for a complete mystical experience, although the author regarded the result as psychological bycatch: the test appeared to classify an experience whose character did not fit the expected spiritual frame.

That mismatch exposes a tension in the phrase. Unity can name the disappearance of ordinary boundaries without deciding whether the disappearance is blissful, sacred, or desirable. In the author’s account, the survey’s vocabulary pulled an experience toward a conclusion that did not match its emotional character. All is One therefore functions both as a description of a reported phenomenon and as an interpretation that can overstate what the experience meant to the person undergoing it.

Scholars of mysticism commonly describe unity as one feature among several: the self and other things are subsumed; ordinary categories such as time, space, and the distinction between self and world lose their hold; the experience may carry certainty, joy, blessedness, sacredness, paradox, and a sense that it cannot be adequately expressed. These features form a family of reported qualities, not a guarantee that every instance will contain them all. The author’s difficulty rating the toad experience demonstrates how a standard list can make unity legible while leaving its particular emotional valence unresolved.

The self, the brain, and claims of truth

Research on the default mode network offers one proposed account of why unity may accompany the loss of self. In Robin Carhart-Harris’s first experiment, the steepest reductions in default mode network activity correlated with volunteers’ reports of ego dissolution. The greater the drop in blood flow and oxygen consumption in that network, the more likely participants were to describe losing their ordinary sense of self. Judson Brewer later noticed that fMRI scans from experienced meditators showed a striking resemblance to Carhart-Harris’s findings: in both contexts, reported transcendence of self accompanied a quieter default mode network.

The proposed connection helps explain how the sense of All is One might arise without settling what, if anything, it reveals about reality beyond the experience. If the boundary between subject and object weakens, consciousness may continue even as the familiar self recedes. Carhart-Harris also suggested that this loss of subjectivity could help account for the feeling that an insight is objectively true: judging an idea as merely personal normally requires a sense of oneself as a subject, and that is precisely what may have diminished. The account explains a possible relationship between self-loss and certainty; it does not establish that the certainty is metaphysical proof.

The book accordingly holds open both the phenomenological force of unity and the possibility of a brain-based explanation. The experience may feel like access to an encompassing reality, while research describes conditions under which the self-world distinction becomes less pronounced. Neither description cancels the other, but they answer different questions: one concerns how the event is lived, the other how it might be associated with brain activity.

A cultural container for the experience

The phrase also appears in contemporary efforts to make profound experiences more available. A draft charter found on a guide community’s website described its aim as supporting access to experiences called unitive or nondual consciousness. It listed meditation, breathwork, and fasting alongside psychoactive substances, understood as potent spiritual catalysts. In this setting, unity is not tied to one substance or a single religious institution; it names an experience sought through different practices.

The community’s documents also recognized that such experiences make participants especially open to suggestion and exploitation. Its ethical code placed responsibility for the client’s well-being on the guide, requiring disclosure of risks, consent, confidentiality, protection of health and safety, restraint from self-promotion, and accommodation regardless of ability to pay. Its guidelines covered preparation, intention, possible drug interactions, difficult material, and post-session integration. These protocols matter to the meaning of unity: they frame it as an experience requiring care and interpretation, rather than as an automatically beneficial revelation.

The clinical sessions described in the book provide another example of how an experience is structured. Patrick Mettes’s planned treatment involved preparatory conversations and two dosing sessions, one using a high dose of niacin as an active placebo and the other a twenty-five-milligram capsule of Psilocybin. During the sessions he would lie on a couch wearing eyeshades and listening to music, with two sitters present. His guide, Tony Bossis, encouraged him to move toward frightening material rather than flee it. This arrangement does not define All is One, but it shows how preparation, music, guidance, and support can shape the conditions in which a participant encounters and later interprets an altered sense of self.

Historical meanings and the limits of universality

The book places contemporary language about mystical unity beside the history of sacramental mushrooms in southern Mexico. The practice had been kept from Western observers after Spanish conquest and repression. A sixteenth-century account by a Spanish missionary described people eating mushrooms before dawn, then dancing, singing, weeping, or sitting pensive; some reported visions of death, animals, warfare, or other events. The record depicts varied experiences and communal practices, not a single uniform doctrine of unity.

The Roman Catholic Church treated mushroom ceremonies as a challenge to its authority. Indigenous people were interrogated and tortured for their participation, and carved mushroom stones were destroyed; in 1620 the Church condemned the use of plants for divination. The conflict was also theological. A mushroom sacrament offered its users what could be understood as direct access to the divine, in contrast with Christian communion mediated by a priest and liturgy. The comparison helps explain why the practice seemed institutionally threatening, but it does not make historical mushroom use interchangeable with modern accounts of mystical experience.

R. Gordon Wasson’s interpretation illustrates the danger of collapsing distinct meanings into one. He arrived in Huautla de Jiménez with a theory that psychoactive fungi lay behind the roots of religious experience, and his account presented María Sabina and the ceremony in terms of communion. Yet the book emphasizes that by 1955 many Mazatecs were devout Catholics and used mushrooms for healing and divination, including locating missing people and objects. Wasson knew of these purposes and told María Sabina he was worried about his son in order to gain access to a ceremony. His framing thus recast a complex, contemporary practice to fit a prior theory about humanity’s encounter with God.

That distinction is essential to reading All is One. The phrase can describe a powerful feature of experience, and the neural and clinical accounts can illuminate how such an experience is approached. But neither the phrase nor a participant’s feeling of unity licenses the erasure of differences among people, practices, or histories. The book’s insistence on those differences makes unity a question to examine, not a final answer.