In Shroom: A Cultural History of the Magic Mushroom, Andy Letcher has given us a thorough and rigorous study of mushroom culture. Among books on psychoactive mushrooms, Shroom is unprecedented in the degree to which the author demands that arguments be supported by evidence. Anyone familiar with the voluminous literature on this topic will immediately recognize this as a revolutionary step; the genre is crowded with speculation ranging from cautious (The Road to Eleusis) to extravagant (Food of the Gods).

A scholar boasting PhDs in both ecology and religious studies, Letcher is also no stranger to the psychedelic underground. In this book he painstakingly reconstructs mushroom theories ranging from Eleusis to Santa Claus. Letcher is highly critical of most of these theories, which he sometimes characterizes in sardonic terms that border on contemptuous. Although his tone can be caustic, he pays mushroom enthusiasts the compliment of taking their arguments seriously and analyzing them as such.

Shroom opens with a serviceable overview of the biology and chemistry of psychoactive mushrooms. The book then moves into the cultural history of mushrooms, including a valuable review of pre-1950s reports of mushroom use. Letcher documents and analyzes nearly every major argument written about psychoactive mushrooms in the last century. He chronicles the channels by which a cloudy mix of science and speculation has flowed into the collective reservoir of the psychedelic underground.

The basic argument that Letcher critiques looks something like this: For thousands of years, humans have had an important relationship with psychoactive mushrooms. After stumbling upon them unawares, our ancestors grasped the power of the psychedelic experience they provide. It may be that the spiritual insights which inspired the major world religions were based on entheogenic mushroom sacraments. The druids of pre-Roman Europe, the ancient Greeks of Eleusis, and perhaps even our early ancestors on the African savanna knew that one could contact the spirit world or commune with the gods under the influence of psychoactive fungi.

This wisdom was tragically lost when conservative elements within the world’s religious institutions began to attack entheogens, driving their use underground. In some cases, the use of mushroom entheogens was secretly transmitted by various codes. Hidden references to mushroom use abound in scriptures and religious art, such as the Soma of the Hindu Rig Veda, which may refer to Amanita muscaria.

The urge to suppress entheogens comes from what Riane Eisler called a “dominator culture” – a patriarchal, hierarchical culture based on power and authority. Such a culture imposes itself on others by force. People living in dominator cultures are alienated from the natural and spiritual worlds, while members of communal egalitarian societies are deeply rooted in the cycles of nature and have an uncontrived, experience-based religious life. Some of these sharing cultures made open and uninhibited use of entheogens, until they were suppressed by dominator cultures, especially the Judeo-Christian culture of Europe.

Sound familiar?

Shroom documents the arguments by which this received wisdom took shape, tracing its origins to the works of figures such as Robert Graves and R. Gordon Wasson. Over time the story was elaborated and extended by Jonathan Ott, John Allegro, Terence McKenna, Clark Heinrich, and many others.

Letcher effectively dismantles nearly every aspect of this mushroom history. In some cases, as in the implausible theories of McKenna, little more is needed than asking “What is the basis for this claim?” In the words of curmudgeon Christopher Hitchens, “A claim that is put forth without evidence may be dismissed without evidence.”

Letcher maintains that the conventional wisdom of mushroom history is rooted in the beliefs and attitudes of members of an industrial society who themselves feel alienated from the spiritual world and from the cycles of nature. Such persons are liable to project an idealized portrait of their own longings onto cultures that are remote in time or in space, such as the Paleolithic hunter-gatherers of Africa or the shamans of Siberia. It is easy to project beliefs onto a druidic culture about which one knows nothing. Letcher demonstrates that the closer one looks at the druids of Europe and the curanderos of Mexico, the less plausible idealized stories become.

Quoting from a considerable number of pre-twentieth century accounts of accidental ingestion of psychedelic mushrooms and finding that the experience was invariably regarded as poisoning or illness, not as spiritual epiphany or gratuitous grace, Lechter contends that there is nothing intrinsic to the experience of eating psychoactive mushrooms such that people in other cultures would necessarily interpret it as valuable.

Stories about the antiquity of psychoactive mushroom sacraments probably owe more to R. Gordon Wasson than any other figure. By Wasson’s own account, he successfully rediscovered secret mushroom cults in central Mexico which had survived the Spanish Inquisition. Wasson argues throughout several books that these mushroom cults are analogous to ancient mushroom cults that inspired the great spiritual traditions of the East (Vedic Hinduism in India) and the West (the Minervic mystery rites in Greece).

Letcher cogently argues that the character of mushroom use in Mexico was distorted by R. Gordon Wasson’s amateurish and biased ethnographies. Wasson arrived in Mexico already convinced that the use of psychoactive mushrooms was related the origin of the world’s religions, and he was eager to find evidence to support his theory. According to Shroom, Wasson turned down opportunities to participate in mushroom rituals with curanderos who did not fit the profile of the sacred mushroom shaman he was looking for. He was overjoyed to find Maria Sabina, whom he could depict as a shaman who used mushrooms in sacred ceremonies. In Sabina’s own account, however, she used mushrooms to heal, not for spiritual enlightenment. A devout Catholic, Sabina found her spiritual needs amply met every Sunday in church.

Letcher builds a strong case that Wasson extruded his observations through the filter of his convictions. The structure of Wasson’s mistakes is common to most of the stories that depict ancient or remote cultures as sacred mushroom eaters. These stories typically begin with a zealous hypothesis, cherry-pick for supporting evidence, and disregard counter-evidence.

Letcher makes an important moral argument that inaccurate and fantastical depictions of other cultures, such as those that abound in mushroom literature, are not merely inaccurate – they constitute a form of intellectual colonialism. Edward Said gave us the term “Orientalism” to describe the process by which remote peoples are exoticized and made into symbols by inaccurate ethnography and fanciful storytelling. Orientalist anthropologies deprive the people they study of their right to their actual history. In Letcher’s reading, Orientalism runs riot through psychedelic mushroom culture, and his sharply-honed arguments are fueled by abundant evidence drawn from anthropology, history, and religious studies.

This review focuses on the broad outlines of Letcher’s argument because the overarching theory warrants analysis. No brief review can do justice to the rich detail and close analysis that Letcher offers. This is an essential book on the subject of psychoactive mushrooms, and an important step forward in the evolution of how we talk about the history of entheogens.