This chapter is excerpted from the expanded 2nd edition of Zig Zag Zen: Buddhism and Psychedelics, edited by Allan Badiner and Alex Grey, published by Synergetic Press.

Join Allan Badiner and special guests Alex Grey, Kokyo Henkel and Brad Warner for a live, interactive course: “Buddhism Meets Psychedelics,” starting July 6th on Evolver Learning Lab. Learn more here.

Mystical experiences are usually conceived of as coinciding with altered states of consciousness. As a result, a consideration of mystical states should begin with a discussion of consciousness itself. Yet the nature of consciousness is one of the most fundamental and difficult of all philosophical questions.

The answers to this question have ranged across an enormous spectrum throughout cultures and eras. At one extreme, they include the idea that con-sciousness is a mere by-product of matter; this is the philosophy of materialism. At the other extreme is the idea that consciousness is the fundamental substrate of reality; this is the philosophy of absolute idealism as proposed, for example, by Yogachara Buddhism. For Nietzsche, consciousness was a suffering-producing disease of life, while for the Vedantic religion of India, it is being and bliss. Small wonder, then, that two contemporary researchers, Douglas R. Hofstadter and Daniel Dennett, claim “So far there is no good theory of consciousness. There is not even agreement about what a theory of consciousness would be like. Some have gone so far as to deny that there is any real thing for the term ‘consciousness’ to name” (Hofstadter and Dennett, 1982).

Yet whatever consciousness is, the desire to alter it is clearly common and widespread. In a cross-cultural survey, anthropologist Erika Bourguignon found that 90 percent of the several hundred societies she surveyed possessed institutionalized means to alter states of consciousness. She concluded that “this represents a striking finding and suggests that we are, indeed, dealing with a matter of major importance, not merely a list of anthropological esoterica” (Bourguignon, 1973). Moreover, she found that in traditional societies, these altered states were viewed as sacred, almost without exception. In his book The Natural Mind, Andrew Weil, a leading researcher on psychoactive substances, concluded that “the desire to alter consciousness periodically is an innate normal drive analogous to hunger or sexual desire” (Weil, 1972).

If this is so, it raises the obvious question of the nature of an “optimal” state of consciousness. This is the question I would like to discuss here, along with a related issue of whether psychedelics can ever induce these optimal states.

In the West it is commonly assumed that our usual waking state is optimal. Yet many religious and contemplative traditions make claims about consciousness that run counter to Western assumptions, among them that:

Our usual state of consciousness is severely suboptimal or deficient; Multiple states of consciousness—including true “higher states”—exist; These states can be attained through training; Verbal communication about them may be necessarily limited.

The teachings of mystical traditions inform us that our usual state of consciousness is not only suboptimal, but dreamlike and illusory. They assert that whether we know it or not, without mental training, we are prisoners of our own minds, unwittingly trapped by a continuous inner dialogue that creates an all-consuming distortion of perception. These traditions suggest that we live in a collective dream variously known as maya, “illusion,” or what psychologist Charles Tart calls “consensus trance.”

Obviously, if these various philosophies regard our usual state as subopti-mal, they must regard some other state(s) as superior. Numerous traditions con-verge on the idea that the unio mystica, described by mystics and saints, consti-tutes the supreme states of consciousness—and in fact is the highest achievement of human existence. In these states the mystic transcends the usual boundaries of ego and feels at one with the universe. Usually the state of mystical union arrives after years or even decades of intense spiritual and mental discipline. This training aims to overcome the fact that, as Sigmund Freud said, “man is not even master in his own house . . . in his own mind.” This is why, as the great Hindu sage Ramana Maharshi expressed it, “all scriptures without any exception proclaim that for attaining salvation mind should be subdued” (Maharshi, 1955).

Yet with the advent of psychedelics in the West came a remarkable claim. Noncontemplatives who took these substances reported a vast range of experi-ences—some high, some low; some ecstatic, some demonic—but also some that seemed remarkably similar to those described by mystics across the centuries. This set off a debate that still rages about the nature of “chemical mysticism.”

Proponents, such as writers and scholars of religion Aldous Huxley, Walter Houston Clark, and Huston Smith, offered arguments supporting the equivalence of chemical and natural mystical experiences. They based their arguments on the experiential similarities between natural and chemical states and on ex-periments such as that of Walter Pahnke, who in 1962 administered psilocybin to students at the Harvard Divinity School before a Good Friday church service. The majority of the group reported a variety of experiences including difficult psychological struggles that sounded indistinguishable from reports of classical mystical experiences. Twenty-five years later, almost all the subjects who were given psilocybin still affirmed that they “considered their original experience to have had genuinely mystical elements and to have made a uniquely valuable contribution to their spiritual lives” (Pahnke Study, 1991).

Others, including scholars of religion R. C. Zaehner and Arthur Koestler, argued vehemently against the idea that a few milligrams or even micrograms of some chemical could possibly induce experiences that contemplatives labor for decades to achieve. In a piece entitled “Do Drugs Have Religious Import?” (the most frequently reprinted article in the history of the American Journal of Philosophy), Huston Smith considered the arguments against the equivalence of chemical and natural mysticism. He concluded that these arguments were unconvincing (Smith, 1964).

The arguments, and Smith’s responses to them, can be summarized as follows:

Some drug experiences are clearly anything but mystical and beneficial. Agreed! But this does not prove that no drug experiences are mystical or beneficial. The experiences induced by drugs are actually different from those of gen-uine mystics. They are obviously different in causation, but, as the Harvard Good Friday study showed, they may be experientially indistinguishable. Mystical rapture is ostensibly a divine gift that can never be brought under mere human control. This argument is, of course, unlikely to convince atheists, nontheists such as Buddhists, or those Christians who believe more in the power of good works than of grace. Drug-induced experiences are too quick and easy to be considered identical to contemplative experiences. However, if the states are experientially indistinguishable, then the fact that they rise from different causes and with different degrees of ease may be irrelevant. The philosopher W. T. Stace has called this “the principle of causal indifference.” The aftereffects of drug-induced experiences are different, less beneficial, and less long-lasting than those of contemplatives. Smith put this point eloquently, noting that if “drugs appear to induce religious experiences, it is less evident that they can produce religious lives.” Nonetheless, the fact that aftereffects may be different does not necessarily mean that the experiences are.

Despite these well-argued points, the debate continues over whether psychedelically induced mystical experiences are “really genuine.” The psychia-trist Stanislav Grof, who probably did more research on psychedelics than anyone else before authorized research was curtailed in the mid-1960s, wrote that “after thirty years of discussion, the question whether LSD and other psychedelics can induce genuine spiritual experience is still open” (Grof, 1980).

One reason the debate continues is that there is no adequate theory of mystical states that could resolve it. For the purposes of this discussion, the term “mystical experience” will refer to an altered state of consciousness characterized by:

Ineffability: the experience is of such power and is so different from ordinary experience that it seems to at least partly defy description; A heightened sense of understanding; Altered perception of space and time; Appreciation of the holistic, integrated nature of the universe and one’s unity with it; Intense positive effect, including a sense of the perfection of the universe.

Such experiences have many names. In the West they have been described as “cosmic consciousness” by Richard Bucke (Bucke, 2001) in his classic work of the same name, and “peak experiences” by the psychologist Abraham Maslow. In the East, common terms include samadhi in yoga and satori in Zen.

We lack a theory that accounts for the induction of identical states by such different means as LSD and meditation, as well as for their different after-effects. It may now be possible to advance such a theory in the light of current understanding.

Psychologist Charles Tart’s model of consciousness is helpful here. Tart suggests that any state of consciousness is the result of the interaction of multiple psychological and neural processes such as perception, attention, emotions, and identity. If the functioning of any one process is changed enough, the entire state of consciousness may shift. It therefore seems possible to reach a specific altered state in more than one way by altering different processes. For example, one may attain states of calm by reducing muscle tension, visualizing restful scenery, or focusing attention on the breath. In each case, the brain-mind process employed is different, though the resulting state is similar.

A similar phenomenon could occur with mystical states. Thus different techniques might affect different brain-mind processes, yet still produce the same mystical state of consciousness. For example, a contemplative might finally taste the bliss of mystical unity after years of cultivating such qualities as concentration, love, and compassion. Yet a psychedelic substance also might affect chemical and neural processes so powerfully as to temporarily induce a similar state.

Tart’s theory of consciousness could explain the supposition that chemical and natural mysticism may be biochemically and experientially identical.

But what of the fact that the long-term effects of the two can differ? These differences may also be compatible with Tart’s theory.

Both psychological and social factors may be involved. The psychedelic user might have a dramatic experience, perhaps the most dramatic of his or her life. But a single experience, no matter how powerful, may not be enough to permanently overcome psychological habits conditioned over decades. The contemplative, on the other hand, may spend decades deliberately working to retrain habits along more spiritual lines. Thus when the breakthrough finally occurs, it visits a mind already prepared. In addition, the contemplative has acquired a belief system that provides an explanation for the experience, a discipline that can cultivate it, a tradition and social group that support it, and an ethic that can guide its expression. One is reminded of Louis Pasteur’s statement that “chance favors the prepared mind.” The contemplative’s mind may be prepared, but there is no guarantee that the drug user’s is.

This is not to say that the contemplative will always be spiritually transformed and the drug user never will be. Some psychedelic users may be psychologically and spiritually mature enough to be transformed by their experience. Likewise some mystics may not be, or at least may have areas of personality, behavior, and neurosis that remain relatively untransformed.

In summary, these ideas suggest a qualified equivalence between contemplative and chemical mysticism; that some drugs can indeed induce genuine mystical experiences in some people on some occasions. However, they seem more likely to do so and more likely to produce enduring benefits in prepared minds.

Yet we may be able to push our investigation a stage further, for it is becoming increasingly apparent that there is not a single type, but rather multiple types, of mystical experiences. In The Spirit of Shamanism I attempted to show that careful mapping of mystical experiences may enable us to identify states that are in reality quite different from each other yet have not been distinguished in the past. For example, the states induced by yoga, shamanism, and Buddhist meditation have sometimes been described as identical. Yet careful comparison of the experiences shows that they may be quite distinct.

The general principle seems to be that different contemplative techniques are more likely to induce certain types of mystical experiences than others, For example, some shamans may feel a sense of unity with the universe, with all of creation (which may be described as “nature mysticism”), whereas Buddhist vipassana meditators aim for an experience of nirvana, in which all objects and phenomena of any kind disappear.

I suspect that careful studies would show that specific psychedelics are more likely to facilitate certain mystical states than others. LSD and analogous substances, for example, may induce experiences of nature mysticism or non-duality more often than nirvanic experiences. Likewise, other substances, for example empathogens such as MDMA (Ecstasy), which are reputed to have a strong “heart” effect and induce feelings of love, may be likely to foster other kinds of mystical experiences. Clearly a further level of sensitivity and discernment may be possible in research on mystical experiences, however they are induced.

For those people who are graced with the mystical experience—whether induced spontaneously, contemplatively, or chemically—the crucial question is what to do with it. It can be allowed to fade; it can be ignored or even dis-missed, or perhaps clung to as a psychological or spiritual trophy. Or it can be consciously used as a source of inspiration and guidance to direct one’s life along more beneficial directions.

One such direction—indeed the one recommended by the great mystics— is to undertake the necessary contemplative training of life and mind so as to be able to reenter and extend the mystical state. The aim is to extend a single peak experience to a recurring plateau experience, to change an altered state into an altered trait, or, as Huston Smith so eloquently put it, to transform flashes of illumination into abiding light (Smith, 1964).

Even this personal experience of abiding light is not the endpoint of the journey. For beyond personal realization lies the stage of sharing that realization with the world, of using one’s wisdom and illumination to teach, serve, help, and heal. The mythologist Joseph Campbell described this as the “hero’s return.” The world’s religions offer many descriptions of this opening of the spirit; in Zen it is called “entering the marketplace with help-bestowing hands,” and in Christianity it is known as the “fruitfulness of the soul.” Thus the task is first to open to the experience of illumination, then to bring that light back to the world for the benefit of all.