Michael Pollan’s psilocybin journey with Mary Cosimano gave him an experience he could recognize as spiritual without taking it as proof of a supernatural reality. Its significance lies in that distinction: the journey felt profound and sacred, and scored as a complete mystical experience on a research questionnaire, while leaving his disbelief in God and cosmic consciousness intact.

A Guide and a Lineage

Mary Cosimano guided Pollan’s psilocybin journey. Her own training connected the session to an underground tradition of psychedelic guidance: the woman who later guided Pollan through an ayahuasca ceremony had trained under Leo Zeff and, in turn, had trained Mary. This lineage situates Pollan’s encounter within an established practice rather than presenting it as an isolated experiment.

The broader guide community described in the book had developed shared methods and written resources. Its draft charter aimed to make profound experiences more available; its ethical code emphasized informed consent, confidentiality, safety, and the guide’s responsibility toward the client. Guidelines for voyagers and guides addressed preparation, intention, possible drug interactions, frightening material, and post-session integration. These documents provide context for the kind of professional and ethical framework around Pollan’s journey, though the account does not specify which particular forms or procedures Mary used with him.

The Journey and Its Images

The journey included an interlude with Bach’s cello music that Pollan later found easier to describe through the language of mystical experience. Reflecting on it, he could recognize a sense of his personal self merging into something larger, a feeling of sacredness and spiritual elevation, and a sense of unity with ultimate reality. The questionnaire’s terms seemed to fit the phenomena more readily than they had during his markedly different toad experience.

The journey also belonged to a wider pattern of encounters in which Pollan felt himself merge with other presences. He recalled the plants in his garden as possessing spirit, and described psychedelic mergings with the cello music, his son Isaac, and his grandfather Bob, each accompanied by an intense feeling of connection. He interpreted these moments through the language of ecology and coevolution: living beings act upon one another as subjects, not merely as objects. When that idea became felt experience, he was willing to call it spiritual.

A Score Without a Conversion

Pollan’s score on the Mystical Experience Questionnaire was sixty-six. That result marked the journey as a complete mystical experience according to the researchers’ threshold, and he felt an almost embarrassing pride in meeting a goal he had set for himself. The number offered a scientific classification for what had happened, but it did not settle what the experience meant.

Despite the score and the sense of sacred unity, Pollan did not emerge believing in God, a supernatural realm, or a cosmic consciousness. The journey had not brought him closer to those beliefs, even though he had partly hoped it might. What it did leave him with was the conviction that something novel and profound had occurred—something he was prepared to call spiritual, but with reservations about what the word implied.

Spirituality Without Supernatural Belief

The journey helped Pollan reconsider an assumption he had long held: that spirituality necessarily rests on a faith he did not share. His experience suggested that a person could undergo a powerful sense of sacredness and unity without adopting a supernatural explanation for it. The questionnaire could register the experience’s recognizable features, but its categories could not dictate a metaphysical conclusion.

That distinction also clarified a paradox Pollan had encountered in Dinah Bazer, an avowed atheist whose psilocybin session had extinguished her fear of death while leaving her atheism intact. Pollan came to understand how an experience described in religious language could remain compatible with disbelief: overwhelming love might feel like grace without being assigned to a divine source. His own journey thus mattered less as a conversion than as a new way to hold spiritual experience and skepticism together.