It's important to be clear that in critiquing the conceptual explanations of experience, as I did in my essay Thinking it Through, I am not denying experience itself. People have experiences. Clearly people have experiences in very many contexts which fall into the vague category of "mystical" experiences - a sense of boundlessness, feelings of transporting bliss, a sense of connectedness, the loss of a sense of self, apparent separation of the self from the physical body, and so on. I certainly do not deny that people have such experiences. To some extent I've had similar experiences. What I don't do is invoke the supernatural to explain and interpret such experience.
It was reading Thomas Metzinger's account of his out-of-body experiences that finally convinced me that a supernatural explanation is never preferable. Metzinger realised that although he initially was drawn to a supernatural perspective on his OOBEs that there was a simple (and to both him and me) a preferrable explanation which invoked the way that the sense of self is constructed in the brain by integrating several streams of input. An OOBE occurs when the integration breaks down. It's definitely worth reading his account (especially before commenting!) though the very brief summary in New Scientist Magazine 23 Feb 2013 may suffice. (I recommend getting hold of this issue and reading the articles on self!) I finished reading The Ego Tunnel and I simply did not believe in the supernatural any more. It was a relief. It means there are some things I can't explain yet, but there is no principial problem with that, and in most cases the lack does not affect my daily life. Though not having a satisfactory explanation for a phenomena does often make us uncomfortable - the human mind abhors a vacuum every bit as much as nature does. For many people a supernatural explanation is preferable to no explanation, despite the many weaknesses of supernatural explanations.
We are capable of having extra-ordinary experiences. We all have them to some extent. At their highest pitch these experiences are radically transformative. One can't have a mystical experience, it seems, and remain the same. It is a watershed where one realises that there is another mode of experience that is unlike ordinary waking experience in its beauty, peace, happiness; unlike dream awareness in that it is coherent and consistent; unlike unconsciousness in that there is awareness. I think Jill Bolte Taylor does a pretty good job of describing this mode of awareness in her TED talk about her stroke: beautiful, expansive, unifying, inclusive, blissful. She stresses the word beautiful several times. Aldous Huxley coined the phrase "opening the doors of perception" for such experiences based on his experimentation with hallucinogens and they do help us to see our world anew.
Many writers have noted such experiences across the full range human cultures. These experiences seem to be available to any human being. Sometimes they come spontaneously; sometimes they are induced through intense austerities or meditation; and sometimes through the use of hallucinogens. The mystical experiences that result become the touchstones for religieux, even if only vicariously (for a large but unquantified proportion of religieux - my guess would be 99%).
Leading members of my Order have been struggling with how to convey this kind of experience. Recently Dharmacārī Subhuti has been experimenting with different kinds of language. A year ago he spoke at an Order gathering about numinous experiences, and confused this with a noumenal realm behind experience, and it was a relief to see him abandon this attempt. These terms are loaded with unhelpful connotations. More recently he has suggested that there is something he cumbrously calls a "supra-personal force" (a term associated with sociologist Max Weber, but also used by psychologist Erich Fromm - Subhūti doesn't cite his sources). The "supra-personal force" is experienced as acting from an egoless perspective. Subhūti's prototypical example being the weeks after the death of Dr Ambedkar when Sangharakshita did his bit to rally Ambedkar's supporters and felt as if "something were working through me" (this period of his life is recounted in his memoire In the Sign of the Golden Wheel). At the peak of experience, the ego melts away and we act on the basis of this "supra-personal force" rather than our own will. Any artist who has created something will most likely be able to describe the feeling of something coming through them as they create. When I have experienced this it is as though I was merely a conduit for something which emerged on a canvas for example, and I could view it quite dispassionately because it did not seem to be "mine" and in a way the whole seemed unrelated to my dabbing paint on a particular part of it. The suggestion is that this feeling is analogous to the egolessness experienced by mystics and meditators. Sangharakshita has also modified a commentarial list -- the fivefold niyama aka the five niyamas -- to provide another name for this "supra-personal force", i.e. dhamma-niyama. It's now common for my colleagues to speak of "the Dhamma-Niyama" as we used to speak of "the Absolute" or "the Unconditioned". I'm not necessarily endorsing any of this, by the way, but I do find it interesting that the traditional ways of discussing mystical experiences are being re-invented by my senior colleagues drawing (without acknowledgement) from various modern(ist) forms of discourse.
There are two important facts embedded in the preceding statements: mystical experiences can be induced by massive left-brain strokes; and they can be induced by chemicals. Indeed we know from experiments conducted in labs that strong magnetic fields which disturb brain activity in certain spots also produce similar experiences; and can add epileptic seizures and migraine to the list of triggers. Even the most ardent proponent of the supernatural must grant that these mystical states have a physical correlate in the brain. The brain is always involved in experience and thus always involved in mystical experiences. Whether this is causal or epiphenomenal or something else is not so important to my argument, I merely wish to state that as far as can be determined there is always a cerebral correlate to experience. I'd be willing to reconsider if someone can show me evidence of the counter, i.e. an experience with no brain correlate, but I'm not currently aware of any such evidence. Direct changes in the brain--through injury or drugs--do change perception and/or personality and/or awareness, and the descriptions of such changes are often indistinguishable from descriptions of mystical experiences.
All of these experiences come under the general banner of 'insight' in Buddhism. But it is reasonable to ask: "in-sight in-to what?" The most general answer is that the mystic has insight into the "nature of reality" and the claim is that the mystical experience is somehow more real than other kinds of experience. The idea being that reality is in fact more like a mystic vision and that other kinds of experience is poor substitutes. I suppose it is inevitable that peak experiences change the way we perceive the world. The peak experience seems to expand possibilities, and even opens new fields of endeavour for us. We know from first hand experience that we can be more, and for some that can be very inspiring. And most people are never the same after their mystical experience - it brings a radical shift in perspective. I've know one or two people dissipate their lives in trying to recreate that peak experience and never quite managing it.
Humans seek out peak experiences is many ways: meditation, drugs, and extreme situations or activities of various sorts. Starvation and painful austerities have often proved popular and effective triggers. People are often willing to risk injury or death in search of a peak experience. And we often dine out on recounting the peak experiences of our lives, or if our lives are very drab we may simply recount the experiences of others. Buddhists with special teachers are prone to the last. It seems that the peak experience defines us in some way. That peak experiences seem more real because they are more intense. Ironically the pursuit of intense experience of any kind merely blunts our sensibilities, which is a consequence of being embodied in an organic feedback system. Either we reach satiation and stop, or if we persist we experience less and less pleasure from our activity and must seek out more intense forms of stimulation. This may be why pain becomes fascinating as an intense experience. As the Buddha said, we mistake the painful for the pleasant.
How we interpret experience, especially peak experience, is heavily culturally determined. We are not free to interpret experience in any old way. We make sense of the world on the basis of some built in concepts such as causality and time (though these are also to some extent culturally determined); and in terms of concepts we learn through our memberships of various groups: family, school, peers, religious groups, etc. So if we have a mystical experience we will understand it in terms of our previously accumulated categories and concepts. Though the experience itself may give us new categories and concepts.
Thus many of my friends have experienced sleep paralysis and all of the creepy sensations involved, but because they live in a house that is supposedly haunted, they describe the experience as involving the ghost(s) of the house. Some are quite convinced they have experienced a disembodied spirit, some are more sceptical but favour the ghost story, and none have been receptive when I point them to the well documented phenomenology of sleep paralysis.
The belief in ghosts or disembodied spirits comes from our pre-scientific past and has persisted through to the present. Ghosts and other entities which survive death are prominent themes in modern literature and film. The ghost belief forms a complex with the prominent stories of the haunted house which is listed in more than one book as "one of the most haunted houses in Britain". The experience of sleep paralysis is certainly unnerving, but why the resistance to the idea that it might just be sleep paralysis? Why does belief persist in the face of plainer, simpler facts? I addressed this in some depth in my essay Facts and Feelings. Beliefs alter the salience of facts so that when we come to weigh things up, certain facts are deemed by us to be more weighty or more important. (Recent research suggests that those with supernatural beleifs find sleep paralysis more distressing - ScienceBlog). Thus the ideas of a ghost outweighs the idea of sleep paralysis for a whole complex of reasons. And not least of which is the impression that being visited by a ghost comes with a certain notoriety and even popularity and everyone wants to hear your story and marvel at your fortitude in dealing with it. Who wants to give that up?
I'm arguing that peak experiences are just like this. We no doubt have experiences. There is no doubting the sincerity of the people who describe these experiences. But for some it is a meeting with god, for others a glimpse into reality, and still others it is non-dualism or egolessness or brahman. There is a clear coherence in the phenomenology of the experiences themselves, but there is no coherence in the phenomenology of the interpretation except in relation to culture. The interpretation is generally in terms of categories we already have.
However sometimes we have experiences for which there are no convenient explanation. In the modern world we cast about, often in popular literature or on the internet, until we find someone or something who can explain what happened. Thus for instance the people who are sincerely convinced that they have been abducted by aliens. Often such inexplicable experiences are what lead us to religion in the first place. Scratch a Buddhist and you often find a trauma.
The sad fact is that however much we pursue such experiences most of us will not have a mystical experience. Even amongst long term meditators (and I know dozens of people who have been meditating for more than two decades) such experiences are relatively rare. Certainly meditation can give us all peak experiences, and I've my share of those, but the mystical or visionary experiences that transform, even radically transform the practitioner are elusive. Most long term meditators are certainly admirable people, but they are refined versions of themselves, rather than egoless or saintly or whatever. For most of us the path produces slow growth and evolution, but not revolution. Personally I mourn the loss of the value placed on cultivating virtues that has come with our societies struggling free of superstition and supernatural religions. I admire people who consciously cultivate virtues such as generosity, harmlessness, contentment, empathy and heightened awareness. So I don't see it as a problem, nor as any great surprise, that most people are not saints.
In my search for better explanations and interpretations I certainly do not mean to devalue the experiences themselves. In some cases my approach does take away the personal kudos attached to an experience like sleep paralysis because my explanation is at first glance more mundane. But only at first glance, because sleep paralysis reveals a fascinating side of our embodied minds and has its own value. It raises all sorts of questions about our embodied minds, and those who explore such questions are producing the most tantalising results.
When I was a youngster (in the 70s) we used to call vanilla ice-cream 'plain'. We'd be asked "Do you want chocolate ice-cream or plain?" As I got older however I began to appreciate that vanilla is a delightful flavour in its own right, and when I first smelt a real vanilla orchid pod I though I had died and gone to heaven. Serrendipitously, in my third-year organic chemistry lab I was handed a vile of white powder and, with no clues, required to identify the compound before the end of the term. So I analysed it (using chemical methods and Nuclear Magnetic Resonance and Infra-red spectroscopy) and it turned out to be 4-Hydroxy-3-methoxybenzaldehyde or vanillin (right) one of the main compounds associated with the smell and taste of vanilla -- artificial vanilla essence is basically an alcoholic solution of methyl- and ethyl-vanillin. If I had a greenhouse I would grow the vanilla orchid. Vanilla ice-cream is my favourite these days. My kind of explanation need not lead to a grey world which lacks meaning. It is not plain compared to the chocolate of the supernatural. My world is full of wonder and colour. Also full of questions to be answered. Life is deeply puzzling. But I no longer feel any need to invoke the supernatural in response to questions and puzzles.