Shroom is, in essence, a big bucket of cold water. Refilled repeatedly, its sobering crash quells the inflamed romanticism of one theory about psychoactive fungi after another.

In one sense, ploughing through this thoroughly researched and succinctly crafted survey of the impact of psilocybin and fly agaric mushrooms on human culture becomes, at times, uncomfortably like watching Casualty. Episodes of this BBC hospital drama invariably begin with characters you’ve never seen before going about some everyday business. It’s hard to relax into their reality, though, because you know what’s coming: a nasty physical trauma and a dramatic trip to the emergency ward. Here, Letcher lines up the tantalizing myths surrounding the iconic red-capped Amanita muscaria, the seductively radical theories of people like Gordon Wasson that place psychedelic plants at the origins of religion, and more. Yet before long you become accustomed to the dramatic tension of knowing that while one hand gestures with some fascination towards these beguiling ideas, the other is ready with the pail of icy water.

What prevents Shroom from the more objectionable dangers of this relentless type of cynical dismissal (usually, a repellent smugness that masks its own naivety) is that Letcher is clearly an “insider”. A veteran of the festival and rave culture of the late ’80s and early ’90s, a one-time fan of Terence McKenna, with a clear fondness for the fungus, he’s the kind of guy you want doing your debunking.

There is, it must be said, much to debunk. Gordon Wasson, who brought a surviving Mexican mushroom cult to global attention in the ’50s, and dedicated himself to propagating theories about the role of mushrooms in ancient religions, is brought under an especially harsh light. His avowed repugnance at the “hippy trail” that his wake generated in the Oaxacan highlands is carefully turned over to reveal his hidden affinity with this phenomenon, his subtly exploitative interactions with the Mazatec Indians clearly exposed as being far from opposed to the post-colonial “spiritual tourism” of the freaks who descended on the area. John Allegro’s infamous The Sacred Mushroom and the Cross is easily demolished, the rubble of his theories left shrouded in clouds of doubt about his murky personal motives. And while Terence McKenna is given plenty of leeway (relative to less recent mushroom proselytizers), his dubious Timewave Zero, and many of his prehistorical musings, are in the end cast aside with extreme prejudice.

It’s difficult, though, to gain a firm grasp on Letcher’s own personal motives. Following the exposition of most of the cherished mycological myths, he prefaces his demolition with something like, “Sadly, this theory does not stand up to scrutiny.” There’s a genuine tone in this slight sadness. But is it that of someone patiently dismantling a deluded friend’s walls of defence, or of someone regretfully sweeping up the detritus of their own youthful over-enthusiasm? There’s probably a bit of both.

It would be easy to accuse Letcher of setting up a straw man, in constructing a one-dimensional target of the uncritical hippy, and taking such a person’s view as the only proposed route into these slippery speculations in order to flatten it. However, such characters do live and breathe—probably cornering Letcher at parties one time too many.

Also, as Letcher is firmly (though not stridently) in favour of an open, rational approach to mushrooms and other such drugs in current society, one suspects a certain tactical necessity at work. Securing a deal with a major publisher for the “definitive” history of the shroom, it may have been prudent, probably shrewd, to prefix a generally tolerant and positive message with lashings of cold facts.

Even so, there are many problems with the book’s approach. It may be true that Shroom wasn’t the place to address these issues, but they deserve an airing here, at least.

In a talk on gnosticism Erik Davis is asked by a member of the audience (inevitably, the venue being the Burning Man festival) whether psychedelic plants might have been involved in early gnostic practices. His response is instructive:

What’s a better question for me is not, “Is it true?” or “Is it not true?”, because they’re both boring. […] We don’t know; and that is the place to work. It’s in watching yourself want there to be a mushroom hidden in that story—or not. […] But we don’t know. And that “we don’t know” is very deep.

“We don’t know” is indeed the core thread that runs through Letcher’s episodic narrative of dismissal. For all the non-loopy theories—proto-hominids munching African shrooms, European cave painters harvesting Liberty Caps, some nebulous drug cult behind the Indian Soma myth, etc.—there is, after harshly dragging the idea through all the counter-arguments, a concession of, “Well, it may well be the case. But the fact remains, we don’t know.”

I, like Letcher, was probably “convinced” for a few years in my early twenties by McKenna’s theory in Food of the Gods, that mushrooms played a vital role in human evolution. But as I delved deeper into prehistorical studies—especially that crucial and compelling arena, the archaeology of rock art—it quickly became apparent that there’s no getting away from the bottom line. We don’t know. Certain physical information is verifiable, and a number of relatively secure inferences can be constructed atop the meager tangible remains of early human life; but past that, in the end, we don’t know and can never know, not for certain.

For me, though, this “don’t know” was the starting point for inquiry, not the end point. Keats’ “negative capability” (“when man is capable of being in uncertainties, Mysteries, doubts without any irritable reaching after fact & reason”) is the baseline. It can be applied as the necessary humility of genuine science (especially in the notoriously shaky social sciences), as much as some vague wishy-washy poetic state. It suggests a tolerant appreciation of limits without castrating the irreducible human urge to understand; consideration of multiple models, always with a psychological eye that sees through itself, rather than the search for monolithic “truth”. Unfortunately, the pressures of academic careerism and the unsubtle filters that mass media force ideas through tend to exaggerate the latter tendency.

Of course, it is exactly this monolithic approach that Letcher discerns and dismisses in people like Wasson. But, in attacking his theory rather than the general cultural ground that feeds both academic orthodoxy and amateur heresies, the power and fertility of “we don’t know” is rather lost. His analysis of us wanting there to be “a mushroom hidden in that story” is brilliant and, in the end, quite forgiving. But there’s a tendency to use analysis of the modern cultural background to these ideas to wipe away their projections into the past, rather than to just loosen their literal solidity a bit while allowing them to still populate our images and narratives of prehistory.

In rounding off his discussion of the important work of David Lewis-Williams and Thomas Dowson on the “trance theory” of prehistoric rock art, Letcher remarks:

There are all manner of reasons why people could have been moved to leave patterns and marks upon rocks and stones. Inspired by nature, they might have wanted to draw ripples or waves. Primitive tools might have limited artistic expression to curves and zigzags. Like doodlers everywhere, prehistoric artists might simply have found the patterns pleasing. Or they might have been bored. […] Academic opinion is at best divided over the model, at worst against it, so once again this particular line of inference reaches a dead end.

Such quotidian possibilities are always useful to keep to hand when considering these archaic creations. But multiple models doesn’t imply a kind of flat relativism where, when considering art that is sometimes found deep in barely accessible tunnels, the “doodling” theory carries equal weight next to the idea of religious trance. Here in particular, Letcher’s agenda of debunking seems to have edged him towards allegiance to some highly questionable factions in an academic battle that he sketches with the kind of broad, biased strokes he so often sees in others’ work.

And again, rather than framing the theory within a network of models, grounded in doubt but willing to entertain possibilities, he finds “a dead end”. “We don’t know” is the overt statement, but it’s so loaded with cynicism that its ambiguity tends to creak under the weight of outright dismissal. As in archaeology, there is lip service to the maxim that “absence of evidence is not evidence of absence”; but impatience with lack of evidence, and with those who abuse this lack, leaves the pregnant void of unknowing in imminent danger of miscarriage.

Summing up the attempts to identify Soma, that slippery but pervasive figure in psychedelic mythology, Letcher laments: “The hard truth is that, while the search for Soma is diverting, exciting even, it is ultimately futile.” Another dead end, and one that fails to see through itself. A key part of Letcher’s argument is that our ideas about the mushroom in other cultures say more about ourselves than about anything else. What, though, does this perception of futility reveal? It demonstrates this book’s frequent allegiance to (or, at least, blunt use of) the positivist quest for literal truth. Anything short of verifiable certainty (and if we’re talking about archaeology and prehistory, that’s most of the object of study) seems disappointingly insubstantial.

The sober adherence to documented history itself creates what is basically a fantasy image of the past. The first recorded instance of a mushroom’s use subtly becomes—however hedged with qualifications about the vast realms of actuality that history inevitably omits—“the first” instance. Letcher fully appreciates the irrepressible nature of the human imagination (this is especially evident in his lucid assessment of the power of the fly agaric to insinuate itself into cultural representations), but as ever, its inevitable role in reifying hard evidence into a fantasy of objective apprehension is left unaddressed in the background.

James Hillman wrote in Re-Visioning Psychology that the ego’s “specific characteristic, and its specific function, is to represent the literal view: it takes itself and its view for real.” He sees the ego as, in the end, just another psychic figure, with its own archetypal background in the Hero—that can-do, literal-minded attitude exemplified by Hercules, who “entered the realm of the shades in order to take something, and while he was there he wrestled, he drew his sword, he slaughtered, and was confused about the reality of images.” Letcher does a sterling job of exposing the heroic ego at work in the early pioneers who descended into the underworld of prehistory looking to return with concrete, incontrovertible mushrooms; but he also leaves largely in place the Herculean lack of appreciation for the airy liminality of Hades that hard-nosed science constellates.

In playing the science game (which, like the ego, is entirely valid, necessary, but takes itself too literally), Letcher may be judged as betraying his subject. Surely the elven, capricious nature of the psychedelic mushroom, eluding both materialist science and rarified de-fleshed spirituality, deserves an imaginal treatment with some fidelity to its source? In a way, though, the mushroom is honoured. The scoffing cynic won’t be confronted with many challenges here, but the probable target audience of the curious or enthused, who have absorbed a little or a lot of mushroom myths, may find the relentless debunking as ontologically challenging as any high-dose psilocybin voyage.

Fidelity to the mushroom and appreciation for the positive openings of “we don’t know” is one thing; what about intellectual coherence? At the fine level of detail, Letcher is usually impeccable. If anywhere, it is again the scientific suspicion of the broad stroke, the generalization, that trips things up. Introducing his study of myth, The Two Hands of God, Alan Watts observed:

When the critical intellect looks at anything carefully, it vanishes. This is as true of the solid substance of bodies as of historical generalizations, of entities such as nations, of epochs such as the Middle Ages, and of subject matters such as myth. The reason is, of course, that “things” exist only relatively—for a point of view or for convenience of description. Thus when we inspect any unit more closely we find that its structure is more complex and more differentiated than we had supposed. Its variety comes to impress us more than its unity. This is why there is something of the spirit of debunking in all scholarship and scientific inquiry. As a historian of science once put it, “Isn’t it amazing how many things there are that aren’t so?”

This quip may be taken as Shroom‘s unofficial subtitle! For various reasons, concern for the variety and difference of cultural phenomena is very much the current academic vogue, and distaste for the blunders of the old-school fascination with cross-cultural similarities comes to the fore here in considering Wasson’s scholarship. The word “armchair” is invoked to magically banish all traces of credibility, as attempts to grasp the ecology of the cultural forest are rejected in favour of a more botanical adherence to the differences between trees.

Here, the discriminating, micro-level critique of the reflective macro perspective is devastatingly accurate, especially in challenging the “cultural evolution” paradigm that informed Wasson’s approach to both the “primitive” Mazatecans and the large-scale dynamics of history when considering the mushroom’s possible role in the origins of religion. Typically, it misses itself. Its implied narrative describes a history of ideas in which the “primitive” approach of armchair generalists has been soundly defeated, consigned to the rubbish tip of academic history to make way for the more advanced, sophisticated constructionist paradigm. In reality, I sense neither view precludes horrendous mischaracterizations of existence, and any current sense of “progress” will in due course dissolve as some further compensatory shift reveals the folly of prioritizing one scale over the other.

For sure, Lewis Carroll almost certainly didn’t base Alice In Wonderland on personal psychedelic experience; but in Alice’s wisdom, taking a piece of both sides of the mushroom—one to make her bigger and the other to make her smaller—he may have left us a useful general hint about epistemology.

Having said all that, I have to end by saying: buy this book. It’s an invaluable source of information, much of it previously scattered in obscure publications, and is consistently entertaining and insightful.

Besides, cold dips are bracing. The obvious hit of frigidity makes it easy to forget that in fact a blast of cold water actually stimulates the circulation to warm us up a bit. The excellent final chapter, with its generous affection for mycological ecstasies, has the ambience of a refreshed afterglow. Despite its faults, in the end the book’s cold water isn’t a repressive crushing of psychedelic passion; rather, it aims to invigorate and refresh. We are wiser for it.