Ψ-ontology and the Nature of Probability

“The wave function is real—not just a theoretical thing in abstract mathematical space.”
—Sean Carroll. Something Deeply Hidden.

Harrigan & Spekkens (2010) introduced the distinction between those theories that take the quantum wave function to be real (Ψ‑ontic) and those which take it to only provide us with knowledge (Ψ‑epistemic). One needs to know that the quantum wavefunction is notated as Ψ (Greek capital Psi) which is pronounced like "sigh". So Sean Carroll's oft stated view—"the wave function is real"— is a Ψ‑ontic approach.

Harrigan & Spekkens seem not to have foreseen the consequences of this designation, since a Ψ-ontic theory is now necessarily a Ψ-ontology, and one who proposes such a theory is a Ψ-ontologist. Sean Carroll is a great example of a Ψ-ontologist. These terms are now scattered through the philosophy of science literature.

Still, Carroll's insistence that fundamentally "there are only waves", is part of what sparked the questions I've been exploring lately. The problem as I see it, is that the output of the wave function is a "probability amplitude"; or over all possible solutions, a probability distribution. What I would have expected in any Ψ-ontology is that the Ψ-ontologist would explain, as a matter of urgency, how a probability distribution, which is fundamentally abstract and epistemic, can be reified at all. In a previous essay, I noted that this didn't seem possible to me. In this essay, I pursue this line of reasoning.

Science and Metaphysics

I got interested in science roughly 50 years ago. What interested me about science as a boy was the possibility of explaining my world. At that time, my world was frequently violent, often chaotic, and always confusing. I discovered that I could understand maths and science with ease, and they became a refuge. In retrospect, what fascinated me was not the maths, but the experimentation and the philosophy that related mathematical explanations to the world and vice versa. It was the physically based understanding that I craved.

As an adult, I finally came to see that no one has epistemic privilege when it comes to metaphysics. This means that no one has certain knowledge of "reality" or the "nature of reality". Not religieux and not scientists. Anyone claiming to have such knowledge should be subjected to the most intense scrutiny and highest levels of scepticism.

While many physicists believe that we cannot understand the nanoscale world, those few physicists and philosophers who still try to explain the reality underlying quantum physics have made numerous attempts to reify the wavefunction. Such attempts are referred to as "interpretations of quantum mechanics". And the result is a series of speculative metaphysics. If the concept of reality means anything, we ought to see valid theories converging on the same answer, with what separates them being the extra assumptions that each theory makes. After a century of being examined by elite geniuses, we not only don't have a consensus about quantum reality but each new theory takes us in completely unexpected directions.

At the heart of the difficulties, in my view, is the problem of reifying probabilities. The scientific literature on this topic is strangely sparse given that all the metaphysics of quantum physics relies on reifying the wave function and several other branches rely on statistics (statistical mechanics, thermodynamics, etc)

So let us now turn to the concept of probability and try to say something concrete about the nature of it.

Probability

Consider a fair six-sided die. If I roll the die it will land with a number facing up. We can call that number the outcome of the roll. The die is designed so that outcome of a roll ought to be a random selection from the set of all possible outcomes, i.e. {1, 2, 3, 4, 5, 6}. By design the outcomes are all equally likely (this is what "fair" means in this context). So the probability of getting any single outcome is ⅙ or 0.16666...

By convention we write probabilities such that the sum of all probabilities adds up to one. The figure ⅙ means ⅙^th of the total probability. This also means that a probability of 1 or 0 reflects two types of certainty:

1. A probability of 1 tells us that an outcome is inevitable (even if it has not happened yet). The fact that if I roll a die it must land and have one face pointing upwards is reflected in the fact that the probability of each of the six possible outcomes add to 1.
2. A probability of 0 tells us that an outcome cannot happen. The probability of rolling a 7 is 0. 

We can test this theory by rolling a die many times and recording the outcomes. Most of us did precisely this in highschool at some point. Any real distribution of outcomes will tend towards the ideal distribution.

In the case of a six-sided fair die, we can work out the probabilities in advance based on the configuration of the system because the system is idealised. Similarly, if I have a fair 4 sided die, then I can infer that the probabilities for each possible outcome {1, 2, 3, 4} is ¼. And I can use this idealisation as leverage on the real world.

For example, one can test a die to determine if it is indeed fair, by rolling it many times and comparing the actual distribution with the expected distribution. Let us say that we roll a six-sided die 100 times and for the possible states {1, 2, 3, 4, 5, 6} we count 10, 10, 10, 10, 10, and 50 occurrences.

We can use statistical analysis to determine the probability of getting such an aberration by chance. In this case, we would expect this result once in ~134 quadrillion trials of 100 throws. From this we may infer that the die is unfair. However, we are still talking probabilities. It's still possible that we did get that 1 in 134 quadrillion fluke. As Littlewood's law says:

A person can expect to experience events with odds of one in a million at the rate of about one per month.

It the end the only completely reliable way to tell if a die is fair is by physical examination. Probabilities don't give us the kind of leverage we'd like over such problems. Statistical flukes happen all the time.

These idealised situations are all very well. And they help us to understand how probability works. However, in practice we get anomalies. So for example, I recorded the results of 20 throws of a die. I expect to get 3.33 of each and got:

1. 2
2. 3
3. 5
4. 1
5. 6
6. 2

Is my die fair? Actually, 20 throws is not enough to be able to tell. It's not a statistically significant number of throws. So, I got ChatGPT to simulate 1 million throws and it came back with this distribution. I expect to see 166,666 of each outcome.

1. 166741
2. 167104
3. 166479
4. 166335
5. 166524
6. 166817

At a million throws we see the numbers converge on the expectation value (166,666). However, the outcomes of this trial vary from the ideal by ± ~1.3%. And we cannot know in advance how much a given trial will differ from the ideal. My next trial could be wildly different.

Also it is seldom the case in real world applications that we know all the possible outcomes of an event. Unintended or unexpected consequences are always possible. There is always some uncertainty in just how uncertain we are about any given fact. And this mean that if the probabilities we know add to 1, then we have almost certainly missed something out.

Moreover, in non-idealised situations, the probabilities of events change over time. Of course, probability theory has ways of dealing with this, but they are much more complex than a simple idealised model.

A very important feature of probabilities is that they all have a "measurement problem". That is to say, before a roll my fair six-sided die the probabilities all co-exist simultaneously:

• P(1) = 0.16
• P(2) = 0.16
• P(3) = 0.16
• P(4) = 0.16
• P(5) = 0.16
• P(6) = 0.16

Now I roll the die and the outcome is 4. Now the probabilities "collapse" so that:

• P(1) = 0.00
• P(2) = 0.00
• P(3) = 0.00
• P(4) = 1.00
• P(5) = 0.00
• P(6) = 0.00

This is true for any system to which probabilities can be assigned to the outcomes of an event. Before an event there are usually several possible outcomes, each with a probability. These probabilities always coexist simultaneously. But the actual event can only have one outcome. So it is always the case that as the event occurs, the pre-event probabilities collapse so that the probability of the actual outcome is 1, while the probability of the other possibilities falls instantaneously to zero.

This is precisely analogous to descriptions of the so-called Measurement Problem. The output of the Schrodinger equation is a set of probabilities, which behave in exactly the way I have outlined above. The position of the electron has a probability at every point in space, but the event localises it. Note that the event itself collapses the probabilities, not the observation of the event. The collapse of probabilities is real, but it is entirely independent of "observation".

Even if we were watching the whole time, the light from the event only reaches us after the event occurs and it takes an appreciable amount of time for the brain to register and process the information to turn it into an experience of knowing. The fact is that we experience everything in hindsight. The picture our brain presents to our first person perspective is time-compensated so that it feels as if we are experiencing things in real time. (I have an essay expanding on this theme in the pipeline)

So there is no way, even in theory, that an "observation" could possibly influence the outcome of an event. Observation is not causal with respect to outcomes because "observation" can only occur after the event. This is a good time to review the idea of causality.

Causation and Probability

Arguing to or from causation is tricky since causation is an a priori assumption about sequences of events. However, one of the general rules of relativity is that causation is preserved. If I perceive event A as causing event B, there is no frame of reference in which B would appear to cause A. This is to do with the speed of light being a limit on how fast information can travel. For this reason, some people like to refer to the speed of light as the "speed of causality".

Here I want to explore the causal potential of a probability. An entity might be said to have causal potential if its presence in the sequence of events (reliably) changes the sequence compared to its absence. We would interpret this as the entity causing a specific outcome. Any observer that the light from this event could reach, would interpret the causation in the same way.

So we might ask, for example, "Does the existence of a probability distribution for all possible outcomes alter the outcome we observe?"

Let us go back to the example of the loaded die mentioned above. In the loaded die, the probability of getting a 6 is 0.5, while the probability of all the other numbers is 0.1 each (and 0.5 in total). And the total probability is still 1.0. In real terms this tells us that there will be an outcome, and it will be one of six possibilities, but half the time, the outcome will be 6.

Let's say, in addition, that you and I are betting on the outcome. I know that the die is loaded and you don't. We role the die and I always bet on six, while you bet on a variety of numbers. And at the end of the trial, I have won the vast majority of the wagers (and you are deeply suspicious).

Now we can ask, "Did the existence of probabilities per se influence the outcome?" Or perhaps better, "Does the probability alone cause a change in the outcome?"

Clearly if you were expecting a fair game of chance, then the sequence of events (you lost most of the wagers) is unexpected and we intuit that something caused that unexpected sequence.

If a third person was analysing this game as disinterested observer, where would they assign the causality? To the skewed probabilities? I suppose this is a possible answer, but it doesn't strike me as very plausible that anyone would come up with such an answer (except to be contrarian). My sense is that the disinterested observer would be more inclined to say that the loaded die itself—and in particular the uneven distribution of mass—was what caused the outcome to vary so much from the expected value.

Probability allows us to calculate what is likely to happen. It doesn't tell us what is happening, or what has happened, or what will happen. Moreover, knowing or not knowing the probabilities makes no difference to the outcome.

So we can conclude that the probabilities themselves are not causal. If probabilities diverge from expected values, we don't blame the probabilities, rather we suspect some physical cause (a loaded die). And, I would say, that if the probabilities of known possibilities are changing, then we would also expect that to be the result of some physical process, such as unevenly distributed weight in a die.

My conclusion is this generalisation: Probabilities do not and cannot play a role in causation.

Now, there may be flaws and loopholes in the argument that I cannot see. But I think I have made a good enough case so far to seriously doubt any attempt to reify probability which does not first make a strong case for treating probabilities as real (Ψ‑ontic). I've read many accounts of quantum physics over 40 years of studying science, and I don't recall seeing even a weak argument for this.

At this point, we may also point out that probabilities are abstractions, expressed in abstract numbers. And so we next need to consider the ontology of abstractions.

Abstractions.

Without abstractions I'd not be able to articulate this argument. So I'm not a nominalist in the sense that I claim that abstractions don't exist in any way. Rather, I am a nominalist in the sense that I don't think abstractions exist in an objective sense. To paraphrase Descartes, if I am thinking about an idea, then that idea exists for me, while I think about it. The ideas in my mind are not observable from the outside, except by indirect means such as how they affect my posture or tone of voice. And these are measures of how I feel about the idea, rather than the content of the idea.

I sum up my view in an aphorism:

Abstractions are not things. Abstractions are ideas about things.

An important form of abstraction is the category, which is generalisation about a collection of things. So for example, "blue" is a category into which we can fit such colours as: navy, azure, cobalt, cerulean, indigo, sapphire, turquoise, teal, cyan, ultramarine, and periwinkle (each of which designates a distinct and recognisable colour within the category). Colours categories are quite arbitrary. In both Pāli and Ancient Greek they only have four colour categories (aka "basic colour terms"). Blue and Green are both lumped together in the category "dark". The word in Pāli that is now taken to mean "blue" (nīla) originally meant "dark". English has eleven colour categories: red, orange, yellow, green, blue, purple, pink, brown, black, white, and grey. To be clear, ancient Indians and Greeks had the same sensory apparatus as we do. And with it, the ability to see millions of colours. It's not that they couldn't see blue or even that they had no words that denoted blue. The point is about how they categorised colours. See also my essay Seeing Blue.

In this view, probability is an abstraction because it is an idea about outcomes that haven't yet occurred. Probability can also reflect our ideas about qualities like expectation, propensity, and/or uncertainty.

When we use an abstraction in conversation, we generally agree to act as if it behaves like a real thing. For example probability may be "high" or "low", reflecting a schema for the way that objects can be arranged vertically in space. The more of something we have, the higher we can pile it up. Thus, metaphorically HIGH also means "more" and LOW means "less". A "high" probability is more likely than a "low" probability, even thought probability is not a thing with a vertical dimension.

This reflects a deeper truth. Language cannot conform to reality, because we have no epistemic privilege with respect to reality. Reality can be inferred to exist; it cannot be directly known. In fact, "reality" is an other abstraction, it is an idea about things that are real. Language need only conform to experience, and in particular to the shared aspects of experience. In this (nominalist) view, "reality" and "truth" are useful ideas, for sure, as long as we don't lose sight of the fact that they are ideas rather than things.

The use of abstractions based on schemas that arise from experience, allows for sophisticated discussions, but introduces the danger of category errors, specifically :

• hypostatisation: incorrectly treating abstract ideas as independent of subjectivity; and
• reification: incorrectly treating abstract ideas as having physical form.

Treating abstract ideas as if they are concrete things is the basis of all abstract thought and metaphor. Treating abstract ideas as concrete things (without the "if" qualification) is simply a mistake.

Abstractions are not causal in the way that concrete objects are. They can influence my behaviour, for example, at least in the sense that belief is a feeling about an idea and thus a motivation for actions. But abstractions cannot change the outcome of rolling a die.

Since probability is expressed in numbers, I just want to touch on the ontology of numbers before concluding.

Numbers

The ontology of numbers is yet another ongoing source of argument amongst academic philosophers. But they are known to avoid consensus on principle, so we have to take everything they say with a grain of salt. Is there a real disagreement, or are they jockeying for position, trolling, or being professionally contrarian?

The question is, do numbers exist in the sense that say, my teacup exists? My answer is similar to what I've stated above, but it's tricky because numbers are clearly not entirely subjective. If I hold up two fingers, external observers see me holding up two fingers. We all agree on the facts of the matter. Thus numbers appear to be somewhat objective.

We may ask, what about a culture with no numbers? We don't find any humans with no counting numbers at all, but some people do have very few terms. In my favourite anthropology book, Don't Sleep There are Snakes, Daniel Everett notes that the Pirahã people of Brazil count: "one, two, many"; and prefer to use comparative terms like "more" and "less". So if I hold up three fingers or four fingers they would count both as "many".

However, just because a culture doesn't have a single word for 3 or 4, doesn't meant they don't recognise that 4 is more than 3. As far as I can tell, even the Pirahã would still be capable of recognising that 4 fingers is more than 3 fingers, even though they might not be able to easily make precise distinctions. So they could put 1, 2, 3, 4 of some object in order of "more" or "less" of the object. In other words, it's not that they cannot count higher quantities, it's only that they do not (for reasons unknown).

There is also some evidence that non-human animals can count. Chimps, for example, can assess that 3 bananas is more than 2 bananas. And they can do this with numbers up to 9. So they might struggle to distinguish 14 bananas from 15, but if I offered 9 bananas to one chimp and 7 to the next in line, the chimp that got fewer bananas would know this (and it would probably respond with zero grace since they expect food-sharing to be fair).

We can use numbers in a purely abstract sense, just as we can use language in a purely abstract sense. However, we define numbers in relation to experience. So two is the experience of there being one thing and another thing (the same). 1 + 1 = 2. Two apples means an apple and another apple. There is no example of "two" that is not (ultimately) connected to the idea of two of something.

In the final analysis, if we we cannot compare apples with oranges, and yet I still recognise that two apples and two oranges are both examples of "two", then the notion of "two" can only be an abstraction.

Like colours, numbers function as categories. A quantity is a member of the category "two", if there is one and another one, but no others. And this can be applied to any kind of experience. I can have two feelings, for example, or two ideas.

A feature of categories that George Lakoff brings out in Women, Fire, and Dangerous Things is that membership of a category is based on resemblance to a prototype. This builds on Wittgenstein's idea of categories as defined by "family resemblance". And prototypes can vary from person to person. Let's say I invoke the category "dog". And the image that pops into my head is a Golden Retriever. I take this as my prototype and define "dog" with reference to this image. And I consider some other animal to also be a "dog" to the extent that it resembles a Golden Retriever. Your prototype might be a schnauzer or a poodle or any other kind of dog, and is based on your experience of dogs. If you watch dogs closely, they also have a category "dog" and they are excellent at identifying other dogs, despite the wild differences in physiognomy caused by "breeding".

Edge cases are interesting. For example, in modern taxonomies, the panda is clearly not a bear. But in the 19th century it was similar enough to a bear, to be called a "panda bear". Edge cases may also be exploited for rhetorical or comic effect: "That's no moon", "Call that a dog?" or "Pigeon's are rats with wings".

That "two" is a category becomes clearer when we consider edge cases such as fractional quantities. In terms of whole numbers, what is 2.01? 2.01 ≈ 2.0 and in terms of whole numbers 2.0 = 2. For some purposes, "approximately two" can be treated as a peripheral member of the category defined by precisely two. So 2.01 is not strictly speaking a member of the category "two", but it is close enough for some purposes (it's an edge case). And 2.99 is perhaps a member of the category "two", but perhaps also a member of the category "three". Certainly when it comes to the price of some commodity, many people put 2.99 in the category two rather than three, which is why prices are so often expressed as "X.99".

Consider also the idea that the average family has 2.4 children. Since "0.4 of a child" is not a possible outcome in the real world, we can only treat this as an abstraction. And consider that a number like i = √-1 cannot physically exist, but is incredibly useful for discussing oscillating systems, since e^iθ = cos θ + i sin θ describes a circle.

Numbers are fundamentally not things, they are ideas about things. In this case, an idea about the quantity of things. And probabilities are ideas about expectation, propensity, and/or uncertainty with respect to the results of processes.

Conclusion

It is curious that physicists, as a group, are quick to insist that metaphysical ideas like "reality" and "free will" are not real, while at the same time insisting that their abstract mathematical equations are real. As I've tried to show above, this is not a tenable position.

A characteristic feature of probabilities is that they all coexist prior to an event and then collapse to zero except for the actual outcome of the event, which has a probability of 1.

Probability represents our expectations of outcomes of events, where the possibilities are known but the outcome is uncertain. Probability is an idea, not an object. Moreover, probability is not causal, it cannot affect the outcome of an event. The least likely outcome can always be the one happen to we observe.

We never observe an event as it happens, because the information about the event can only reach us at the speed of causality. And that information has to be converted into nerve impulses that the brain then interprets. All of this takes time. This means that observations, all observations, are after the fact. Physically, observation cannot be a causal factor in any event.

We can imagine a Schrodinger's demon, modelled on Maxwell's demon, equipped with perfect knowledge of the possible outcomes and the precise probability of each, with no unknown unknowns. What could could such a demon tell us about the actual state of a system or how it will evolve over time? A Schrodinger's demon could not tell us anything, except the most likely outcome.

Attempts by Ψ-ontologists to assert that the quantum wavefunction Ψ is real, lead to a diverse range of mutually exclusive speculative metaphysics. If Ψ were real, we would expect observations of reality to drive us towards a consensus. But there is a profound dissensus about Ψ. In fact, Ψ cannot be observed directly or indirectly, any more than the probability of rolling a fair six-sided die can be observed. 

What we can observe, tells us that quantum physics is incomplete and that none of the current attempts to reify the wavefunction—the so-called "interpretations"—succeeds. The association of Ψ-ontology with "Scientology" is not simply an amusing pun. It also suggests that Ψ-ontology is something like a religious cult, and as Sheldon Cooper would say, "It's funny because it's true." 

Sean Carroll has no better reason to believe "the wavefunction is real" than a Christian has to believe that Jehovah is real (or than a Buddhist has to believe that karma makes life fair). Belief is the feeling about an idea.

Probability reflects our uncertain expectations with respect to outcome of some process. But probability per se cannot be considered real, since it cannot be involved in causality and has no independence or physical form.

The wave function of quantum physics is not real because it is an abstract mathematical equation whose outputs are probabilities rather than actualities. Probabilities are abstractions. Abstractions are not things, they are ideas about things. The question is: "Now what?" 

As far as I know, Heisenberg and Schrödinger set out to describe a real phenomenon not a probability distribution. It is well known that Schrödinger was appalled by Born's probability approach and never accepted it. Einstein also remained sceptical, considering that quantum physics was incomplete. So maybe we need to comb through the original ideas to identify where it went of the rails. My bet is that the problem concerns wave-particle duality, which we can now resolve in favour of waves. 

~~Φ~~

Bibliography

Everett, Daniel L. (2009) Don’t Sleep, There Are Snakes: Life and Language in the Amazon Jungle. Pantheon Books (USA) | Profile Books (UK).

Harrigan, Nicholas & Spekkens, Robert W. (2010). "Einstein, Incompleteness, and the Epistemic View of Quantum States." Foundations of Physics 40 :125–157.

Lakoff, George. (1987). Women, Fire, and Dangerous Things: What Categories Reveal About the Mind. University of Chicago Press.

On the Cognitive Linguistics of Emptiness

This essay applies an analytical method developed by George Lakoff and Mark Johnson, especially as it occurs in the book Metaphors We Live By, originally published in 1981, with a revised edition 2003. I will also draw on their other published works, notably Lakoff (1987) and Johnson (1987). Lakoff and Johnson tell us that "cognitive metaphors" are ubiquitous in human language. These metaphors involve treating a target domain as if it were a member of the same category as the source domain. In these metaphors the source domain is usually some form of physical interaction that humans have with the objective world, and the target domain is some feature of cognition. In this way, cognitive metaphors are what enable us to think about the world in abstract terms. 

This is a modern form of philosophical analysis not available to the ancient world. So this type of analysis offers the possibility of new insights when applied to old discourses. This method has occasionally been applied to Buddhism in the past, though the application has been patchy and the methods involved have not become mainstream. In this essay, I am going to use the methods developed by Lakoff and Johnson to critique the abstract concept of "emptiness" as we mainly meet it in accounts of Buddhism. In this case, I'm not criticising any particular usage, but want to make some general points about the concept. 

Cognitive Metaphors

A metaphor involves treating one things as if it were another. In a series of five blog posts in 2016, I outline John Searle's account of social reality in which "as if" plays a major role (see Social Reality). In that account of social reality I noted that language is an institutional fact:

Language itself only works because of collective intentionality, i.e. we all agree that certain verbal sounds count as words; that certain words count as representing concepts; that certain combinations of words count as sentences, and so on. (Institutional Facts & Language: Social Reality. II).

What this means is that language relies on us all agreeing that a given word means what it means.  As Wittgenstein famously said, 

“For a large class of cases—though not for all—in which we employ the word “meaning” it can be defined thus: the meaning of a word is its use in the language.” (Wittgenstein 1967, section 43)

This is often abbreviated to "meaning is use". Individualism has a role to play in the evolution of language, especially where the individual is influential.  But, generally speaking, language relies on our collective agreement on what words mean (semantics) or do (pragmatics). Cognitive metaphors are no different; other people must understand our use of cognitive metaphors in order for us to communicate about abstractions. 

The metaphor relation is not arbitrary. It is not that anything can be anything. The relation requires that the target domain has some properties that make it a good candidate for metaphorical projection. I won't go more deeply into this since it involves invoking the image schema and explaining this is too involved for an essay like this one. The standard work on image schemas is still (as far as I know) Mark Johnson's book The Body in the Mind (1987). Suffice it to say that the target domain for the metaphor must be a good fit. 

For example, we may state a commonly used cognitive metaphor: IDEAS ARE OBJECTS. (I use Lakoff and Johnson's convention of citing metaphors in small caps). In this metaphor, the source domain is our physical interactions with objects, while the target domain is a subjective experience of thought. If we accept the metaphor IDEAS ARE OBJECTS, then any operation we can physically perform on an object we can perform mentally on an idea. If I can grasp an object, then under this metaphor I can grasp an idea, as if it were an object. I can turn an idea over and look at it from another angle. I can look at an idea from different angles. If I have more than one idea, I can juggle them. I can throw an idea out, toss it around, and kick it into the long grass. Virtually anything I can physically do with an object finds a metaphorical application to an idea under the cognitive metaphor, IDEAS ARE OBJECTS.

A poor metaphor might be IDEAS ARE COWBOYS. Cowboys ride, bait, and subdue semi-wild animals for entertainment. It's not clear in what way an idea is like a cowboy. This metaphor is not intuitive. Another one might be FISH ARE BICYCLES. Note that these propositions are not forbidden by the rules of English grammar. Still, they don't make for obvious metaphorical usage. The metaphor IDEAS ARE OBJECTS works because ideas have a limited scope, they can often expressible in a succinct way that makes each idea seem discreet from other ideas. Expressing the idea leads to a transfer of that discreet piece of knowledge to another person. It's not that an idea is an object, but that an idea is sufficiently like an object in specific ways. The similarity occurs at the level of "image schemas", which I'm trying to avoid for reasons of brevity. 

It may seem simplistic to labour the point, but I think it's worth saying that ideas are not real objects. In making the metaphor, we are not reifying the abstraction. Moreover, contrary to the prevailing view of humans amongst Buddhists, people are not easily fooled into reifying cognitive metaphors. It would be odd for a person to claim that ideas are objects in a substantial sense. We know this is not true. No one ever literally held an idea in the palm of their hand, for example. We know it's a metaphor and we intuitively deal with thousands of such metaphors every day. If we had to stop to analyse each one, abstract thought would not be possible.

Unlike a computing language I don't have to "declare" the metaphor before using it. We effortlessly decode hundreds and thousands of these cognitive metaphors on the fly without even noticing that we are doing it. When people are sitting around a table at a meeting and someone says, "we need to move on", and they change the subject rather than getting up and leaving the room, no one is surprised by this.

In this case, it is because we can form a cognitive metaphor: A CONVERSATION IS A JOURNEY. For example, we might be having a conversation and it "takes a turn" (perhaps a strange or unexpected turn, or a turn for the worse). Someone might wish to "return" to what was said earlier. If it's going badly, we might say "Let's start over". If the conservation was difficult but productive, we may say: "we got there in the end". When a conversation is at an impasse, we might say that we have to move on and leave the impasse unresolved. And a conversation may reach a natural conclusion: "let's stop there".

These cognitive metaphors are not incidental but rather they form an integral part of language use. The richness of our metaphorical use of language is part of what makes us human. Our ability to talk about one thing as if it were a member of a completely different class of thing is what distinguishes human communication from all other animals. Clearly, some animals and birds are capable of abstract thought to some extent. But they don't communicate in metaphors. We do. 

Once we get attuned to this idea of cognitive metaphors, we begin to see them everywhere. When I talk about typing on my keyboard (a physical act) and words appearing "on my screen" this is two cognitive metaphors: WORDS ARE OBJECTS and SCREENS ARE SURFACES. Of course the screen is literally a surface, but the words are not on it in a physical sense. I can't physically interact with words on a screen. Even on a touch screen that's not what is happening. Rather the patterns of light and dark created by pixels make words seem to appear on the screen, and electrical interactions between surface and finger help to create the illusion of physical interaction. At the end of the day there is dust and fingerprints on my screen, but no physical objects called "words". Still, all the verbs that can be used to describe interacting with objects on a surface, can now be applied to "words on a screen".

In order to get at the underlying metaphors involved in talking about emptiness in a Buddhist context, we have to consider the use of container metaphors.

Container Metaphors

A very common cognitive metaphor involves likening something to a container. For example, in English we have the metaphor: A BOOK IS A CONTAINER. A book can, for example, be filled with ideas (here again: IDEAS ARE OBJECTS). With this combination we make a complex source domain: putting objects into a container maps onto putting ideas or words into a book. We use the same verb in each case, but use it substantively on one hand and metaphorically on the other.

A very common metaphor in English is MIND IS A CONTAINER and more specifically, mind is a container of experiences. In this view, experience happens in the mind; experience is the content of the mind qua container of experiences. Interestingly, however, Indian Buddhists do not seem to have used a specific container metaphor that we take for granted: i.e. sensory experience is contained in the mind. In Buddhism, the mind (manas) is more like a translator that turns (physical) sensory experience into (mental) perception. An ancient Buddhist could not, for example, say something like "empty your mind" because this relies on the container metaphor and they did not conceive of the mind as a container or sensory experience as the content of the mind. They are more likely to use a surface metaphor for the mind, and to talk about sensory experience as a disturbance of that surface. They may also talk about a sensory event in terms of the sense organ being struck by the appearance of an object. Keeping in mind that "appearance" (rūpa) is to the eye as sound is to the ear.

Despite the fact that ancient Buddhists did not use the container metaphor for the mind, it is so ingrained in us as English speakers that it's almost impossible to not think of the mind as a container and sensory experience as the content. 

Given all this, what can we say about how to understand the term "emptiness" (Skt. śūnyatā)

Emptiness and Experience

The adjective "empty" and the abstract noun "emptiness" are part of the broader cognitive metaphor involving containers. There is no abstract "emptiness" in the absence of a container that could potentially contain something. Moverover, emptiness in the dictionary sense boils down to "the absence of content". "Emptiness" is defined by the Online Etymology Dictionary as "the state of containing nothing". Similarly Merriam-Webster defines emptiness as "containing nothing, not occupied or inhabited" and "lacking reality, substance, meaning, or value."

These definitions are curiously opposed to Buddhist definitions of "emptiness" which specifically state that it does not mean "void" or "nothingness". As one writer seeks to clarify:

"Emptiness is not complete nothingness; it doesn't mean that nothing exists at all. This would be a nihilistic view contrary to common sense." - Lewis Richmond.

In other words, in a Buddhist the concept "emptiness" does not mean emptiness, at least in any general sense. Rather it means, we are told, that things are not as they appear to us. It is the difference between appearance and reality. In which case, "emptiness" is obviously the wrong term for this concept. Still I want to press on and consider the cognitive metaphors that apply to our English word and circle back to the doctrinal mismatch.

Any given container—physical or metaphorical—may contain something or not, but to be a container it must potentially contain something. If a container contains anything, then it is not empty. If it contains nothing, it is empty. 

Note that this is unrelated to the expected content of the container. I drink my morning coffee from a teacup I like. The rest is in a thermos and stays hot. One could say that my cup is empty of tea, for example, but by being specific one falls down a rabbit hole. My cup may well be empty of tea, water, lime-juice, cooking oil, kerosene, and every other kind of liquid, but it presently is filled with coffee and thus my cup is not empty at all. This gives emptiness an important parameter. Emptiness tends to be an absolute: if my cup has any kind of content, then it is not empty. My cup is only empty when there is no liquid in it; i.e. when there is emptiness.

So far, so logical. But this is not how Buddhists, especially Mādhyamikas, use the termin practice. Mādhyamikas use the abstract noun "emptiness" in a concrete sense. The classic example is the statement "form is emptiness". This is a valid English sentence, but there is something wrong with it. Even when we take "form" to be "form in the abstract" (or matter generally as many Mādhyamikas do), this sentence is not logically valid because it is trying to equate two different levels of abstraction. "Form" here is generally taken to mean "phenomena". If the metaphor is FORMS ARE CONTAINERS then we might validly state that form is empty. 

There are several problems here. The first is that rūpa is (in English at least) not the container of experience, it is the content of experience (or part of it). Rūpa is to eye what sound is the ear. And note that this applies across the senses. Importantly, rūpa is to the eye as tangibles (spraśtavya) are to the body (kāya). Rūpa is on the wrong side of the equation to be equated with body, even metaphorically. In Chinese, rūpa is routinely translated as sè 色 "hue (from original meanings "form, appearance, complexion"); visual surface quality." (definition from Kroll). In Sanskrit, rūpa is typically a property of a surface reflecting light, it is not a metaphorical container. 

That said, there is no doubt that some modern Buddhists do take rūpa to mean "substance", "matter", or "body". We can see that this is incoherent even at face value since the word is neither defined that way nor used that way in ancient texts. Even the translation "form" misleads most English-speakers into thinking in substantive terms about rūpa. Rūpa means "appearance". Moreover, even if we invoke the container metaphor, it can't be applied to rūpa because rūpa is an element of experience, this is to say that rūpa is content. Ancient Buddhists preferred to see rūpa as a disturbance on the surface of the mind, but even in this metaphor, rūpa is not substantive.

The second problem is that even if rūpa were a container we could go as far as saying that it is empty if it did not contain anything. We could not logically assert that it is "emptiness". If emptiness is the absence of content and rūpa is content, then the two are logical contraries. Despite a great deal of hand waving in modern Buddhist philosophy, "form is emptiness" simply does not make sense in English. But then it doesn't make any more sense to state this in Sanskrit; rūpameva śūnyatā is still equating two different levels of abstraction. This is an egregious wrong turn in Buddhist philosophy.

I might never have thought of this had I not discovered that the phrase was not originally rūpaṃ śūnyatā "form is emptiness", but rūpaṃ māyā "appearance is illusion" (Attwood 2017). This equation occurs in Aṣṭa and in a few places in Pañc as well. It is clearly translated into Chinese by Kumārajīva as 色不異幻、幻不異色，色即是幻、幻即是色。 (e.g. at T 223, 8.239c6-7). Here huàn 幻 translates māyā "illusion", though it originally meant "creation" or the creative power of the devas to keep the world in harmony (ṛta). Given the long history of Buddhists comparing sensory experience to an illusion this makes perfect sense. A classic example of this is the Pheṇapiṇḍūpama Sutta, which concludes with a well-known verse:

Pheṇapiṇḍūpamaṃ rūpaṃ, vedanā bubbuḷūpamā /
Marīcikūpamā saññā, saṅkhārā kadalūpamā;
Māyūpamañca viññāṇaṃ, desitādiccabandhunā (SN iii.142).

Appearance is like a ball of foam, valence like a bubble.
Recognition is like a mirage, volition like a plantain.
Discrimination is like an illusion. So Ādiccabandhu taught.

Here, Ādiccabandhu means the Buddha, but it is a distinctively Brahmin name completely unconnected to any of the standard myths of the Buddha. A similar verse occurs at the end of the Vajracchedikā, where the simile becomes a metaphor:

tārakā timiraṃ dīpo māyāvaśyāya budbudaḥ |
supinaṃ vidyud abhraṃ ca evaṃ draṣṭavya saṃskṛtam ||Vaj 22 || (Harrison and Watanabe 2006)

We should see the conditioned as a star, a kind of blindness, a lamp;
An illusion, a dewdrop, a bubble, a dream, a lightning flash, a cloud.

We also find the simile in Aṣṭa, “appearance is like an illusion” (māyopamaṃ rūpam. Vaidya 1960: 9). And this is all quite straightforward: experience and reality are not the same thing; different rules apply. 

There is a popular rhetorical strategy for dealing with "form is emptiness" amongst Buddhists which can be illustrated with a random example from the Tricycle website:

Avalokita found the five skandhas empty. But, empty of what? The key word is empty. To be empty is to be empty of something.

If I am holding a cup of water and I ask you, “Is this cup empty?” you will say, “No, it is full of water.” But if I pour out the water and ask you again, you may say, “Yes, it is empty.” But, empty of what? Empty means empty of something. The cup cannot be empty of nothing. “Empty” doesn’t mean anything unless you know empty of what. My cup is empty of water, but it is not empty of air. To be empty is to be empty of something. This is quite a discovery. When Avalokita says that the five skandhas are equally empty, to help him be precise we must ask, “Mr. Avalokita, empty of what?”

What we see here is a fantastic distortion of reality, leading to a false conclusion. It is nonsensical for you to ask me what my cup is empty of, because to be empty in any sense, it has to be empty of everything. As I noted above, my cup could be and regularly is empty of tea (and all other liquids) but full of coffee: in which case my cup is not empty at all. The conclusion here—“Empty” doesn’t mean anything unless you know empty of what—is simply not true. This is a case of the tail wagging the dog. That is to say, we know what the answer had to be in order to legitimise Buddhist dogma on emptiness, and the question is phrased in such as way as to elicit only that answer. But in doing so, Buddhists blithely defy the conventions of language. 

We can never legitimately ask "empty of what?" The question is meaningless and the answer is simply a restatement of a dogma that doesn't make any sense. The idea that "empty of what" is a natural question is either extraordinarily naive or disingenuous. Either way, Buddhists propagate this falsehood in all sincerity. 

This invalid method and false conclusion are often parlayed into an even worse question using the abstract noun: "emptiness of what?" Such a thing is not allowed under English grammar. Emptiness is emptiness. "Of what" is an entirely meaningless question because if the answer is not "everything", then the vessel is not empty at all. 

We do sometimes suggest that emptiness might have degrees.  For example, we may say that a cup may be half full or half empty. Still, it's only from the point of view of being half full that we can ask "of what?" The "of what?" question only applies to the content of the container. An empty container has no content; a half empty container is half empty of all content. Even if we say the glass is half empty, no one in their right mind asks "Half empty of what?". This is simply not how the container metaphor works. 

We can see that the cognitive linguistic perspective is a powerful method for understanding utterances. But it also highlights how dogmatic the Buddhist discourse on emptiness is. This kind of invalid logic is de rigueur for Buddhist philosophy and is almost never questioned or critiqued: either from within or without. Rather such views are carefully curated by Buddhists, in the sense of being framed as deep truths, discovered by visionaries and mystics, and accompanied by frenzied hand waving so that they can be presented as something they are not, i.e. true. This is what we expect of a religious philosophy or theology. There are axioms that cannot be questioned or the whole thing would fall apart. The fabric of Madhyamaka is held together with unquestioned, religiously inspired, axioms. 

The same argument holds for Sanskrit which has identical cognitive metaphors. In Sanskrit it is nonsensical to say rūpaṃ śūṇyatā, but it is sensible to say rūpaṃ māyā, and even better to say rūpaṃ māyopamaṃ "appearance is like an illusion"

So my, rather awkward conclusion is this: Buddhists don't seem to understand the concept of empty, let alone the concept of emptiness. If they did understand, the question "empty of what?" would never occur to them. Worse, Buddhists routinely insist that this flawed concept of emptiness is what makes sense of Prajñāpāramitā. Two wrongs don't make a right. 

In this case, how should we understand the word emptiness?

Making Sense of Emptiness

The key here is to note that the first use of śūnyatā as a technical term is to refer to the state of meditative concentration in which all sensory experience has ceased due to the withdrawal of attention from the senses. This state is called suññatāvihāra or śūnyatāsamādhi. Since sensory experience is dependent on attention (manasikāra), by practising non-attention (amanasikāra), one prevents sensory experience from arising and causes arisen sensory experience to cease. 

Here, sensory experience can be seen as the content of experience or, in Buddhist terms as a distortion of the (naturally) smooth surface of the mind. As such, sensory experience may be present or absent and even admit degrees of these. Hence, between ordinary waking awareness and emptiness there are numerous stages (āyatana) of increasingly attenuated sensory experience. But here, too, absence is absolute; the presence of an any sensory experience means that emptiness doesn't apply. This point is made repeatedly in the Aṣṭasāhasrikā, for example. Emptiness in this case, is the complete absence of sensory experience. 

There are several Buddhist approaches to analysing the content of experience: a range of reductive ontologies into which experience is analysed. For example, the skandha-ontology, which focuses on the processes that give rise to experience, or the dhātu-ontology, which is focussed on the sense faculties and their objects. Mainstream Buddhism foregrounds this reductive, analytic approach of breaking experience down into simpler components in order to eliminate it as a source of absolute being. That complex objects disappear under analysis is not some great metaphysical truth, it is simply a consequence of methodological reductionism. 

If I dismantle my chariot, of course I no longer have a working chariot because I've just broken it on purpose. Who does that? Why would I want to dismantle a working chariot in the first place? And why would my destruction of the thing constitute proof that it never existed in the first place? This is the claim that many Buddhists make but, again, it is nonsensical.   

Prajñāpāramitā Buddhists, building on a tradition that is probably older than Buddhism itself, sought first to bring sensory experience to a halt. They didn't analyse sensory experience in any depth because the acme of their program was not an insight into sensory experience. What they sought, first and foremost, was an insight into death and rebirth. The whole fetish of emptiness was originally established on the analogy of emptiness with death. Mastery (vidyā) over sensory experience, in the form of the ability to voluntarily make it stop, equated to mastery over repeated death. This mastery was and is the driving force of Buddhism, even when it is buried in centuries of intellectual accretion. 

My current thinking is that the discovery of how to do this probably arose around the same time as major socio-political changes in India, reflected in, for example, the replacement of red and black pottery type by the painted grey ware style of pottery. Within a few centuries we see the emergence of walled city states which are stable for some 200-300 years before the Moriyan Dynasty of Magadha overwhelmed all the others, founding the first pan-Indian empire. One possible source of mind-training techniques that limit sensory experience is the "interiorisation" of Brahmanical rituals. In this development, some Brahmins began to perform their daily rituals in imagination rather than physically. This led to the discovery of radical changes in sensory experience, especially in the form of hallucinations due to sensory deprivation, and ultimately to the cessation and absence of sensory experience. By the time the Bṛhadāraṇyaka Upaniṣad was composed (in or around the Kingdom of Kosala) the correct performance of rituals was being linked to one's afterlife destination. Buddhists and Jains had similar ideas but focussed on actions more generally, with Buddhists refining this to just volitional actions. 

However it happened, it is apparent that in this milieu some religieux developed and shared the techniques that allowed them to bring sensory experience to a halt and to dwell in a state in which there is awareness but no content. Some Buddhists called this "emptiness" (śūnyatā). Other Buddhists called it "extinction"(nirvāṇa) and other names. This state is also known in modern times as "contentless awareness", "minimal phenomenal awareness", or "non-dual awareness". 

This is how I presently understand "emptiness" in Prajñāpāramitā.  I believe this is a better approach than anything based in later traditional interpretations based on the Madhyamaka telos (which sees Prajñāpāramitā merely as proto-Madhyamaka). 

Dharma as Container?

One of the key concepts in Madhyamaka is "the emptiness of dharmas". In this usage, dharmas have to be considered as metaphorical containers. The broader translation of dharmas as "phenomena" (as distinct from noumena; i.e. appearances rather than reality) seems to fit here, but what is the content of  a phenomenon? Is there really any phenomenon that is not sensory experience?

Nāgārjuna tells us that he expects that we will expect a dharma to have svabhāva in the sense of being autopoietic or self-creating. Nāgārjuna points out that this self-creating property of dharmas cannot exist in any changeable phenomenon. So far so good. The problem is that no one ever believed in self-creating dharmas. No one ever proposed this before Nāgārjuna. But he said that everyone believed it. Nāgārjuna appears to have lied about this. What puzzles me is that no one really cares about the lie. Many people seem to prefer this lie. 

The svabhāva of a dharma, according to Abhidharma lore, is the sui generis quality that gives us the ability to identify it. For example, it's important to all Buddhists to distinguish skillful (kuśala) motivations (cetanā) from unskillful (akuśala) ones. If I experience a moment of greed or generosity, I identify it as such by introspecting the content of the experience. The fact that I can identify an experience as motivated by greed or generosity doesn't imply anything like Nāgārjuna's autopoietic dharmas. As far as I can see, there is no way to even infer autopoietic dharmas from any early Buddhist doctrine. We have different kinds of experiences and these are identifiable by certain characteristics. No one disputes this, not even Nāgārjuna. 

However, Nāgārjuna also assumes that to be real a dharma must have svabhāva in his autopoietic sense. This axiom is incoherent, but is blindly accepted by all and sundry; even Graham Priest, the academic logician, seems to fail to see this basic logical error in Nāgārjuna's argument. Since he can (trivially) prove that no dharma can be autopoietic, he then deduces that dharmas are not real, that they don't exist. But this definition of "real" is completely incoherent. Not only did Buddhists never use this definition of real, they weren't even interested in the question of the reality or unreality of dharmas. They were interested in the arising and ceasing of dharmas; especially in the light of a state in which all dharmas cease except for the asaṃskṛtadharma, i.e. emptiness. Emptiness is asaṃskṛta because it does not occur due to the presence of a condition but rather occurs when all conditions for sensory experience are absent. 

In order to square the circle, Nāgārjuna has to introduce the nonsense idea of a "relative truth", which is not true at all. The ultimate truth, in this view, is that dharmas don't exist, because they are not self-creating. I can see no good reason to take Nāgārjuna seriously as a philosopher or even, frankly, as a Buddhist. He seems to have entirely missed the point of Buddhism and has gone off on a tangent. And still, he is routinely cited as "the most important Buddhist philosopher". 

Conclusion

The term "emptiness" is generally used in an incoherent way by Buddhists, especially in statements containing the idea "emptiness of...". We can never legitimately ask "empty of what?" let alone "emptiness of what?" because this is not how the container metaphor works. 

The idea that the proposition "form is emptiness" is meaningful now seems doubtful. Moreover, when we look at the kinds of post hoc arguments put forward to justify this proposition, they simply don't make sense. In addition, we know that it used to make sense when presented in the form: "appearance is an illusion." A sensory experience is like an illusion. I doubt anyone would argue with this.

It is also true that in the state called "emptiness" there are no dharmas because that state occurs only when all dharmas have ceased and no new dharmas are arising. This sense of the term is far more coherent than the general religious consensus that emptiness is reality. 

The incoherence reaches its apotheosis in Madhyamaka rhetoric about the emptiness of dharmas, by which Mādhyamikas mean that they think dharmas don't exist, since they tie existence to self-creation and it is trivial to show that dharmas cannot be self-creating. Nāgārjuna insists on an incoherent definition of what "real" means and uses that to argue that the concept of existence is incoherent. Prior to Nāgārjuna no one ever used this definition of real. Apart from his devotees, most Buddhists still don't use this definition. 

The standard ways we have of talking about this all seem to miss the point. Early Buddhists did not venture opinions on the existence or nonexistence of dharmas, except in the case of the sarvāsti doctrine. Even the Sarvāstivādins did not argue that the existence of dharmas was due to self-creation. The logic of sarvāsti is completely different but not difficult to follow. If a past dharma can be the cause of a present effect, then the doctrine of dependent arising itself says that it presently exists since imasmin sati, idaṃ hoti and imasmin asati, idaṃ na hoti. If the dharma doesn't exist now, then it cannot be a factor in the arising of a dharma in the present. This central argument is not even considered by Nāgārjuna, let alone refuted. 

The nature of dharmas is irrelevant in light of the fact that dharmas arise and cease, depending on where our attention goes. To say that dharmas lack svabhāva in Nāgārjuna's sense is trivial. To say that they have svabhāva in the Abhidharma sense is also trivial since we routinely recognise hundreds of different kinds of experience (for which we have thousands of words). The key to understanding Prajñāpāramitā lies in another direction entirely. The main point is that attention can be withdrawn from sensory experience. When we withdraw attention from sensory experience, it ceases, leaving us in a particular state characterised by some kind of basic awareness without any experiential content. That is, in a state of emptiness.

While it is not essential to my critique of Madhyamaka, it helps to understand the cognitive metaphors of emptiness and how cognitive metaphors function generally. This is so because "the emptiness of dharmas" is a cognitive metaphor: DHARMAS ARE CONTAINERS. But this is only true if dharmas exist and are capable of acting as metaphorical containers.

Still, it is only Madhyamakas who believe that in order to exist, to be real, a dharma must be self-creating. "Self-creation" is an odd choice for the content of that container. I can imagine a thing being self-creating, but I cannot imagining a thing containing self-creation. Self-creation doesn't fit the cognitive metaphor. 

So even if we could legitimately ask "empty of what?" the answer "empty of self-creation" is nonsense on several levels. For example, it would require us to relate to "self-creation" as content. To my mind this simply doesn't work. "Self-creation" is not a suitable target for the source domain of things we put in containers, except in the very broadest sense that IDEAS ARE OBJECTS. The idea of self-creation might be the content of a metaphorical container, the fact of self-creation cannot be.  

On the other hand, the emptiness of the mind, i.e. the concept of the absence of mental content in meditation, is not plagued by these inconsistencies and incoherences. In English it is natural to use the container metaphor for this. It is not so natural in scriptural languages, but, nevertheless, the absence of dharmas in meditation is the key concept here, not the absence of being self-creating. The whole idea of self-creating dharmas is a red herring. 

The metaphysical speculations that attract us as explanations for emptiness are largely based on prior indoctrination. In my reading, such speculations are absent from both early Buddhism and Prajñāpāramitā. This is not to say that metaphysics is generally absent from or irrelevant to Buddhism.  All ancient Buddhists believed in karma and rebirth, for example. These involve commitments to metaphysical views that we now know to be false, though few Buddhists will admit to this. 

The methods of cognitive linguistics are a powerful tool for thinking critically about Buddhist doctrines. That said, most existing applications of these methods have been in the service of tradition, i.e. used purely descriptively by scholars who have no interest in critiques of Buddhist philosophy. Whatever the reason for it, this side-stepping manoeuvre allows those people to continue evangelising for traditional Buddhism without ever confronting the inevitable antinomies between Iron Age or Medieval thought in India and present day science and philosophy. Many Buddhists seem attracted by the idea of subsuming all knowledge within Buddhism. This tends to involve a rather blasé form of dualism in which science is merely concerned with the "physical" and Buddhism is concerned something that we often see called "spiritual".

Unfortunately, this exceptionalist discourse appears to obscure and devalue the real contribution of Buddhists, i.e. the cultivation and exploration of states of contentless awareness. I see this as a lose-lose scenario. I see the neuroscience community studying this phenomenon and developing their own terminology for it, though at present we still see a proliferation of different terminologies. At some point, an objective account of the methods and consequences of meditation will eclipse the religious accounts. Those who insist on the religious accounts, with all their incoherence and misdirection, will be relegated out of the conversation and become irrelevant. I'd prefer to see experienced meditators staying in the game, but as long as they cling to outmoded forms of talking about emptiness, they will not be part of the conversation for much longer. 

~~oOo~~

Bibliography

Attwood, J. (2017). "Form is (Not) Emptiness: The Enigma at the Heart of the Heart Sutra." Journal of the Oxford Centre for Buddhist Studies, 13,52–80. http://jocbs.org/index.php/jocbs/issue/view/15/showToc.

Johnson, Mark. (1987). The Body in the Mind: The Bodily Basis of Meaning, Imagination and Reason. University of Chicago Press.

Lakoff, George. (1987). Women, Fire, and Dangerous Things: What Categories Reveal About the Mind. University of Chicago Press.

Lakoff, G. & Johnson, M. (2003). Metaphors We Live By. New Ed. [Originally published 1981]. University of Chicago Press.

Some Notes on Cessation and Prajñāpāramitā

My thirteenth article on the Heart Sutra has been published. 

(2022) "The Cessation of Sensory Experience and Prajñāpāramitā Philosophy" International Journal of Buddhist Thought and Culture 32(1):111-148. IJBTC Website. [free download]. Academia.edu

In this article I directly address the philosophy of Prajñāpāramitā as it occurs in Prajñāpāramitā texts for the first time (for me, and probably for you too). I'm not the first to attempt to explain Prajñāpāramitā, by any means. That said, these days I'm operating in an entirely different paradigm to scholars like Edward Conze or Linnart Mäll, or religious leaders like the Dalai Lama and Thich Nhat Hanh. I never did fully accept the metaphysical speculations that surround this genre, which always sounded screwy to me, but now I know there is a better alternative. As usual, I rely a great deal on pioneering work by Sue Hamilton, Jan Nattier, and Matthew Orsborn (aka Huifeng).

Hamilton (2000) explores an epistemic reading of early Buddhism, notably the khandhas. She shows that it is far more coherent to think of the Buddha as being concerned with experience rather than with reality. Indeed, there is no Pāli word that corresponds with our concept "reality" and few, if any, texts that discuss reality or the nature of reality. What the Pāli suttas mainly discuss, amidst all the myth and miracles, is sensory experience and, in particular, the cessation of experience during meditation. That sensory experience can cease without loss of consciousness is the key discovery that sets Indian religion and philosophy apart. A great deal of Indian religion seems to me to be bound up with the implications of this discovery.

Nattier (1992) showed that the text was composed in Chinese, and both Huifeng and I have independently confirmed this by showing that the patterns she observed in the core passage can be seen throughout the Heart Sutra. Huifeng (2014) was the first to notice certain mistakes in the Sanskrit text that have contributed to our misreading of the Chinese Xīn jīng «心經». He noted, at the time, that the corrected text points to the need for an epistemic reading if the Heart Sutra. In 2015, I published the first of a series of articles pointing out long-standing, but unrelated, mistakes in Conze's critical edition of the Prajñāpāramitāhṛdaya. Between us, we ought to have created enough doubt to suggest the need for a reappraisal of Prajñāpāramitā philosophy. 

This essay is a kind of supplement to the published article, with more background information. I begin with some history.

Some History

At around the time that city states were emerging on the central Gaṅgā Valley floodplains, new religions , or Dharmas, were emerging in the region: theistic Brahmanism, Sāṃkhya, Jainism, Ajivaka-ism and, of course, Buddhism. And these appear against a backdrop of local animistic religions from which Buddhism  got yakkhas, tree-spirits, and other non-human (amanussa) beings. Archaeologists tell us the new cities begin to appear in the sixth century BCE. The cities are mainly kingdoms and several of them are characterised by imperialism and military conquest. The Moriya dynasty of Rājagaha and Paṭaliputta went on to spawn a subcontinent spanning empire in the third century BCE. Of the ancient cities from that time, only Varanasi (Pāli: Kāsī) has been continuously occupied.

Incidentally, although it is de rigueur to give historic names in Sanskrit, the practice is incoherent. Almost no one outside of the Punjab spoke Sanskrit at that time. The other thing that emerged at this time were the Middle Indic (or Prakrit) languages, the everyday speech of people in those regions was not the Old Indic saṃskṛtabhāṣya recorded by Pāṇini. The new vernacular languages probably don't derive directly from the language of the Brahmins, either, since that was only one form of Old Indic and preserved only within a hermetic community of Brahmins. In particular, there can be no suggestion that Lāja Piyadasi, aka King Asoka, ever spoke or used Sanskrit in any way. It is anachronistic to refer to him in Sanskrit as Aśoka (or Ashoka).

I have speculated (Attwood 2012), based some informal comments by Michael Witzel, that one catalyst for the social transformation that resulted in city and Prakrits emerge was the arrival of small groups of people (including the Vajji, Mallas, Kāmālas, and Sakkas) who initially migrated into India from Persia (bringing with them some Persian ideas and customs, a few of which were incorporated into Buddhism). After a dry spell, they moved into the interior, avoiding the Brahmin territories to the north, and settled on the margins of the emerging city states in the Gaṇgā Valley, where they took up the patterns of life that we see depicted in Pāli stories.

We have little reliable evidence for this period, but it seems likely, from texts like the Bṛhadāraṇyaka Upaniṣad and the Ariyapariyesanā Sutta, that meditation in the sense of withdrawing attention from sensory experience was discovered by a group of migrant Brahmins living around the city of Kosala who were experimenting with visualising rituals, rather than acting them out (sometimes called the "interiorisation of ritual").

However it happened, the early hagiographies of the Buddha show him learning how to meditate from non-Buddhist teachers whose attainment of the āyatana states are consistent with attention-withdrawal being their main technique and who are distinguished only by how far they got with it. Buddhists, especially the Theravāda sect, were at pains to show the Buddha breaking away from his early teachers and finding his own technique, which we now refer to as jhāna (Skt dhyāna). But there are also suttas in Pāli, notably the Cūḷasuññata Sutta (MN 121), that show Buddhists still doing the older style of meditation in which one withdraws attention and reflects on the absence of sensory experience that results from this. The persistence of this thread in Buddhism in the Buddhist canon is all the more interesting when we consider that it went against the flow of Buddhist orthodoxy, which at that time was rapidly moving towards focus on Vinaya and Abhidharma. In this sense we can think of Prajñāpāramitā as an innovative literary form emerging from a conservative community of meditators. 

Learning to withdraw attention from sensory experience can be fascinating. Not least because it is functionally identical to sensory deprivation and has the same side effects, i.e. visual, aural, and somatic hallucinations. Experienced meditation teachers tell us that the weird sensations, lights, and even sounds that we encounter in our minds when we first learn to meditate are not significant. However, as sensory deprivation intensifies we may have more vivid hallucinations with a hyperreal quality that very often are judged to be significant. We tend to call these types of hallucinations "visions" and attribute a heightened meaning to them. Many meditators feel that their "visions" have revealed an ineffable truth about the universe to them. As yet there seem to be no scientific studies of the role that sensory deprivation and consequent hallucinations play in Buddhist meditation (I've dropped hints with some of the leading neuroscientists via Twitter: look up people like Karin Matko, Heleen Slagter, Thomas Metzinger, Ruben Laukkonen, etc).

Ancient texts like the Cūḷasuññatā Sutta tell us that beyond all this foam of ephemeral sensory experience there is a state (variously deeper or higher depending on preferred cognitive metaphors) in which all sensory experience has ceased (nirodha), is extinguished (nirvāṇa), or absent (śūnya). I speculate that after emerging amongst Brahmins in the Kosala region, these techniques were taken up by all the religions of Second Urbanisation India. People of those various religions were all practicing attention withdrawal but (then as now) interpreting the results differently according to their own doctrines. 

The Buddhist explanation of the absence and presence of sensory experience became the dependent arising doctrine, which some Buddhists sought to make a theory of everything. In this view, sensory experience arises dependent on the presence of conditions (imasmin sati idaṃ hoti), one of the main conditions being "attention" (manasikāra). In manasikāra, the kāra refers to "a maker" and manasi is manas "mind" in the locative case. In English we naturally want to read this as "in the mind", but I'm a little doubtful about whether ancient Buddhists had the cognitive metaphor: MIND IS A CONTAINER (see The 'Mind as Container' Metaphor 27 Jul 2012). In translation the locative typically becomes the prepositions "in, on, at, etc," but we can also read it as "with reference to". So manasikāra would be "a maker with respect to the mind". It is apparent that in some contexts words like manas, citta, and vijñāna were seen as interchangeable; while in other contexts they have distinct technical meanings. We typically take this context to be temporal, with technical terms emerging relatively "later" than undifferentiated forms. But this is a presupposition and as far as I know there is no evidence external to the texts that could corroborate this. Such differences need not be temporal at all. They might be sectarian, for example, or geographical. We really don't know. 

A Digression on Causality and Proximity

I'm sometimes chided by orthodox Buddhists for saying that dependent arising implies the presence of the condition; a view on this that I notably share with Anālayo (2021). A prominent Theravāda scholar and journal editor once insisted that the formula only requires the existence of the condition. At the time, I was flummoxed by this but found it difficult to articulate why. 

In modern arguments about causality (which is more rigorous than mere conditionality) physical proximity (or locality) is required for causation. Causation or action at a distance is a deeply problematic idea. Where we see apparent action at a distance, such as magnetic attraction, we always find some intervening medium (the electromagnetic field) or an alternative explanation (gravity is not a force, but an effect of the geometry of spacetime). Most modern scientists and philosophers would question whether any action at a distance is possible on the macro-scale that Buddhism deal with. There is an exception for nanoscale at which is seems that locality may be up for grabs. Causation, as far as any Iron Age Buddhist could have understood it, at a minimum requires the cause to be in the same physical location as that which it acts on, or immediately physically proximate to it. This is not only a logical necessity, but is also implied by the grammar of the Pāli formula of dependent arising. 

So, I can now more confidently insist that the dependent arising formula states that a condition must be present for an effect to arise. It's existence is insufficient if, for example, the condition existed on the other side of the planet at the bottom of the ocean, then there is no possibility of it causing an effect here in my house. 

From Experience to Reality

Causality is a tricky topic (especially if we are trying to understand an Iron Age worldview), but it is easy compared to "reality".  The word is used so vaguely and ambiguously that sometimes it hardly seems to mean anything. Defining "reality" is next to impossible without invoking some other metaphysical quality. For example, we might say that reality is that which exists. But what does it mean to exist? Philosophers are still arguing about this one.

In my view, to be "real" is to have some observable quality that is, or some qualities that are, independent of any particular observer or their beliefs.  It is entirely possible that some real things cannot ever be observed by us. About such things we know nothing and at this stage we likely never will. Many things that might be observed have not been. Think of bacteria which existed for billions of years, but were first observed in the eighteenth century.  

For those aspects of reality that are apparent, all observers agree on some ontologically objective facts. For example, gravity on earth is experienced as an acceleration of 9.8 ± 0.03 m/s² towards the centre of the planet, and everyone who measures it accurately gets a value in that range. Variations can be explained by the inherent measurement error, and the thickness and density of the earth's crust at the point of measurement (the oblate-spheroid shape of the planetis a factor in this). Gravity is not a matter of opinion. It is not produced by each person individually. Gravity is a fact that transcends the observer. How we explain the universality of gravity depends on the context. 

Those who argue that the material world is an illusion or is generated by the mind, have no interest in explaining a phenomenon such as gravity. It's just part of the "illusion". Illusion and related words are often bandied about in this context. We often see clickbait headlines like "Reality is an illusion" or "self is an illusion". But this is not a form of explanation: it does not help us to understand the concepts involved. Even if something is actually an illusion—like "the dress"—simply calling it an illusion leaves open all the important questions. 

That said, gravity certainly does not behave like an illusion, it behaves like a "brute fact". Anyone who seriously doubts this could try jumping off a tall building while fervently imagining that they can fly to test their belief (Darwin Awards await). 

Some Buddhists are surprised to discover I distinguish experience from reality. They wonder if they not one and the same thing (i.e. they are Idealists). The reasoning is usually along the lines of "mind creates reality". This is a misconception. If mind did create reality, then there would be no reason for everyone to imagine gravity being 9.81 ± 0.03 m/s². There would be nothing to prevent me from inventing gravity at 5.6 ± 0.3 m/s². or any arbitrary figure. In the absence of an objective world, what could possibly account for the uniformity and universality of gravity? I've yet to see any convincing explanation of this from an Idealist. 

NB the standard figure for gravity is often given with greater precision that the measurement error allows. The standard figure is 9.80665 m/s² but the variation due to error is on the order of two significant figures (0.03 m/s²), so the standard figure cannot have a precision greater than that, i.e. 9.81 m/s².

Gravity is just one of many universal quantities that we know of. Others include the mass of a proton, the charge of an electron, and the speed of light in a vacuum. Explaining these from an Idealistic worldview is difficult at best. Universality seems to requires something extrinsic to the observer  in order to impose standardisation but how to achieve this in a nonmaterial, idealistic worldview? An objective universe, independent of observers, is far and away the simplest and most elegant solution to shared knowledge and universal constants. Over the last 450 years, scientists have described our universe to an exquisite level of detail, often to 10 or 12 decimal places, so that in terms of our everyday world, we now completely understand the processes involved. On this see these blog posts by Sean Carroll. 

• The Laws Underlying The Physics of Everyday Life Are Completely Understood.
• Seriously, The Laws Underlying The Physics of Everyday Life Really Are Completely Understood.

The gaps in our understanding of the universe as a whole are huge, but they are at the extremes. The physics of human scales of mass, length, and energy are fully comprehended by the atomic theory of matter and forces. Buddhist idealism is forced to sweep 450 years of science under the carpet and pretend that it is inconsequential compared to what Buddhists say they learn in meditation about the nature of reality. 

Early Buddhists didn't explicitly say, but they did imply that they accept the existence of an objective world. An objective world is not a problem for early Buddhist doctrine, or for Prajñāpāramitā, because the focus is on sensory experience and what happens to our minds when we withdraw attention from sensory experience. The nature of the objective world is, at best, secondary to questions about the nature of experience and the meaning and significance of the complete cessation of sensory experience. As long as the nature of reality allows for sensory experience and cessation it doesn't matter what we believe about it. Especially in Iron Age India when it seemed plausible to take nirvāṇa as an analogue of death, so that by attaining the former, we bring the latter to an end. Once rebirth caught on, the end of it became the avowed goal of all known Iron Age Indian religions. 

Still, getting from objectively real to objective reality is a much bigger step than most people realise.

From Reality to Myth

My approach to abstract concepts like "reality" is broadly speaking nominalist. In this view, reality is the abstract notion that all real things have something in common that qualifies them as real. This common quality then retrospectively authenticates a phenomena as "real". On a nominalist reading, however, abstractions themselves are not real. Abstractions are ideas that we have about experience. Abstracting a perceived commonality and then retrospectively using that abstraction to define what is "real" is a method that produces nonsense. I noted above that it's very difficult to define reality from first principles. Part of the problem is that "reality" is an abstraction; an idea. And this allows that different people can define reality differently depending on their idea. This also means that a phenomenological account of "reality" is no help: what kind of phenomena is an idea? Ideas are subjective phenomena. So how can a subjective phenomena be used to define something objective? 

A further problem we routinely face in Buddhism is that many Buddhists believe in a magical reality over and above "mundane reality". In other words, many Buddhists are openly dualistic about this world (ayaṃ loko) and the world beyond (paraṃ loko). This is typical of all religions that emphasise "life after death". Many Buddhists insist that there is a more real world, or a real world juxtaposed with the world of illusions reflected by sensory experience, waiting for us after death, be it nirvāṇa or a buddhakṣetra. The world of experience is, at best, a poor reflection of a "spiritual" (read "magical") reality beyond. For example, my bête noire, Edward Conze openly argued for a magical [his word] reality existed over and above physical reality. Moreover, he apparently believed this for many years before he ever encountered a Sanskrit text. He managed to shoehorn this view into a Marxist analysis of Aristotle long before he shoehorned it into Prajñāpāramitā. 

There is an obvious attraction in the idea of a "world beyond"; a world that has none of the flaws of our world; a world that is not broken, cruel, and merciless; a world in which all of our desires are fulfilled, and so on. One need not labour the point since a better afterlife is the essence of what all religions promise followers. Although it is notable that some early Buddhists stated that their intention was "the end of the world" (lokassa anto). 

It's not until the Pure Land texts that we see this idea of a magical reality beyond the "mundane" world begin to take hold in Buddhism. Before this there were better and and worse rebirths, but all rebirth was problematic. Rebirth in a "heaven" (devaloka) only prolongs the inevitable and has no soteriological value. Indeed, some Buddhists say that liberation is only possible from the human realm (manussaloka).

Because there can only be one Buddha at a time (by Buddhists' own definition) and Gautama disappeared from our world when he died. Gautama brought rebirth to an end and his post-mortem status was officially "indeterminate" (avyākṛta). But this was apparently interpreted in some quarters as Gautama abandoning us to our fate. In response to this Buddhists invented alternative universes where living Buddhas could still be found who were willing to "save" us. These Buddhas effectively live forever and would rescue any faithful devotee from saṃsāra. At first this centred around the Buddha Akṣobhya and his buddhafield Abhirati, but he was soon eclipsed by Amitābha who lives in Sukhāvati and is much less demanding: a single act of recalling his name (nāmānusmṛti) is enough to draw his attention and he comes to our universe to collect us after death so that we are reborn in Sukhāvati and from there attain liberation from rebirth. The two sutras that describe this are both called the Sukhāvativyūha Sūtra. They seem to have appeared around the same time as Prajñāpāramitā literature and have proved to be amongst the most influential texts in Buddhist history. It's likely that theistic Pure Land followers are the majority of all Buddhists worldwide. 

Such stories are mythological. That is to say, these stories reflect the values of some Buddhists at some point in time and space, expressed in symbolic, often anthropomorphic, terms. The stories don't reflect actual events. Myths are not objective histories to inform us about the past. As noted, Buddhist myths reflect a growing dissatisfaction with the idea that Gautama simply left us behind when he ended his own stream of rebirths. A really good person, they reasoned, would have stuck around to give us a helping hand: who could look at the world and not conclude that it desperately needs help? Not me. The Buddha was supposed to be the epitome of good. 

A little later a related idea emerges, i.e. the idea of a pluralistic Buddha who at one level seemed to be a human man, but the mortal man was merely a material manifestation of a timeless, immaterial, undying principle of awakening. The issue of the Buddha's apparently short lifespan is tackled in this way in the Suvarṇabhāsottama Sūtra (aka the Golden Light Sutra). These are religious myths, but Buddhists the world over either believe that they are objectively true or behave as if they describe reality. Again, this is theism, turning the Buddha into a god.

At around the same time as these myths were emerging and taking Buddhism in innovative directions, some Buddhists, notably one known as Nāgārjuna, began to assert that the absence of sensory experience is reality. This is the essence of Madhyamaka metaphysics, for example. We often see this stated as "emptiness is reality" as though this means something, although I think it does not. Mādhyamikas also say things like "dharmas don't exist", although whether or not Nāgārjuna said this or even implied it is moot. The problem here is that although there is a state in which all sensory experiences cease, asserting that this state is reality is problematic since it lumps all phenomena into the "not real" category, which is completely absurd and creates paradoxes. In short, reifying the absence of experience following gets us nowhere. But some Buddhists still value the contradictions and paradoxes that this stance throws up. They seem to find the existence of paradox as confirmation that they are on the right track whereas I would say that a paradox either reflects our ignorance or a mistake. In the case of Prajñāpāramitā it is both: we were naively ignorant of the context and misled by the lies of Edward Conze (et al) to believe that paradox was normal when, in point of fact, paradox and contradiction play no role in Buddhism until substantially later. 

Not Doing Metaphysics

Talk of grand abstractions like truth, reality, and existence all comes under the heading of metaphysics. Anyone who gives an opinion on "reality", let alone the "nature of reality" is ipso facto doing metaphysics. Hence, I do not believe Mādhyamikas when they claim not to be doing metaphysics but assert that they understand or have experienced the nature of reality. 

Humans are constantly trying to discern the reality that lays behind or beyond sensory experience because we all know that our eyes can be deceived. In modern terms, the world we experience is a virtual model created by the brain (as demonstrated, for example, by phantom limb syndrome or the Capgras delusion). The better our model of the world is, the better our chances of survival and procreation. Most of us are not naive realists. We do understand that reality and experience are not identical and we strive to minimise the differences or errors. When we foreground this in our thinking we may become more reticent about drawing conclusions about reality based on unusual experiences. 

When someone makes an assertion about reality or has an opinion on what is real, it is always legitimate to ask "How do you know?". Doing this we find that Buddhists place high value and significance on experiences in meditation. Some of these experiences have all the hallmarks of hallucinations caused by the brain's response to sensory deprivation. In the end, the one thing that makes all the difference is the  fact that sensory experience can cease, though I still hesitate to call this "an experience". Along the way we lose our sense of our body, our sense of self, and our sense of a world "out there". In the end, when all sensory experience has stopped and we are still alive and aware, we find ourselves in an contentless but nonetheless hyperreal state that begs to be assigned meaning and significance. The cessation of the sense of self, for example, is often seen as evidence of the nonexistence of self. 

However, "I don't see it" and "It doesn't exist" are very much not the same thing. 

The mystic says that the experience of, say, selflessness, is sufficient to establish that our "self" is not real. This is a metaphysical conclusion. But it's also solipsistic (i.e. egocentric). One of my most striking memories of timelessness in meditation was on a long retreat. I was deeply concentrated and sat on after the bell rang for the conclusion of the session. While I was there not noticing the passing of time, the other retreatants prepared, cooked, and served a meal. That took time; about one hour in fact. Time that I didn't notice passing. The obvious conclusion here is not "time is not real" or "time doesn't exist", but that I was unaware of time passing for about an hour while everyone around me had a pretty normal experience of time. This is an epistemic conclusion. It lacks the panache and glamour of metaphysics, it doesn't cast me as the hero of the story, but it's more intellectually honest. 

The weight of evidence is that most of these kinds of metaphysical conclusions that appeal to Buddhists are factually wrong. What other conclusion might someone who has experienced, say, the cessation of their self come to? I like to use the example of Gary Weber who reports that he has no sense of self. I find Weber very credible, so I believe him when he says that he doesn't experience much if any sense  of self. And yet, wildly contrary to Buddhist doctrine, he takes this to mean that everything that happens is predetermined and events unfold without any influence from us whatever. He will tell you that we don't really make decisions, we are just carried along falsely believing that our desires cause our actions, when in fact it's all just a fixed set of events playing out as they were always going to. Clearly this is a very different metaphysical conclusion than your average Buddhist would arrive at based on experiences that seem to be exactly the same. 

An alternative explanation that occurs to me is that the apparently selfless might conclude that selfing, the activities of the self, is now going on unconsciously. This would help explain why a person with "no self" is able to carry on a conversation for example, as Gary Weber obviously does. A conversation is a complex social interaction in which each participant has to keep track of who said what to whom, and whose turn it is to talk. It seems to me that this would be impossible without some sense of self/other dichotomy. If someone who has no sense of self is conversing normally, we might want to conclude that their selfing was now unconscious. Unconscious selfing presents fewer problems than conscious selfing, because the role of self-centeredness is reduced. Moreover it is considerably less problematic than the view that no self exists, even in people who sincerely believe that they are experiencing themselves as a self from moment to moment. 

In Triratna we often talk about this in psychological terms, particularly in terms of the subject/object duality "breaking down". Many, perhaps most, of us take this to mean that the subject/object duality is not real. The corollary, that the absence of a subject/object duality is reality, follows but all the same caveats apply to us as to others. Just because we can experience the subject/object duality breaking down, does not mean that it is not real or that it doesn't exist. And so on. 

The Alternative: An Epistemic Approach

Reality is a complex subject. And the relationship of experience to reality is not clear either in Buddhism or in some modern accounts of mind. 

The mind-body problem is one of the most famous philosophical conundrums. My own view is that the dichotomy is not really one of mind and body but is, more fundamentally, a matter-spirit dichotomy. That is, I take the distinction to have deeper roots in our basic ideas about the material world and another world of invisible life-force often associated with the afterlife. This is a prominent topic in my book Karma and Rebirth Reconsidered and in a range of blog posts. My sense is that while most scientists  now eschew the grosser forms of matter-spirit dualism (since they don't believe in "spirit"), the average person still has a profoundly dualistic outlook. Almost everyone I know believes in an afterlife for example, and this necessitates some ontological dualism. 

In epistemic terms the subject/object duality is real since we get information about subjectivity and objectivity through completely different sensory modalities: introspection and extrospection. One way of thinking about meditation is that it shuts down extrospection and leaves us in a purely subjective state. If we mistake this purely subjective state for objective reality, then we may be tempted into the conclusion that "mind makes reality", but this requires that we give no value whatever to objectivity. And this seems a perverse way of thinking about it. 

Dualisms are deeply embedded in how humans conceptualise the world. And when we take the distinctions to be metaphysical, as we do in matter-spirit dualisms, we find ourselves in tricky territory. What usually happens is that having divided the world into two, we dismiss one part (usually matter) as unreal. Materialism, as John Searle pointed out, is a dualism in which proponents divide the world into material and non-material halves and declare the non-material to be unreal. This manoeuvre has consequences. If the mind is non-material, then the materialist is left with no explanation of it except to argue that it is an illusion. 

An epistemic approach to this problem rapidly finds purchase and leverage over this particular dualism. As I say, there is an obvious epistemic distinction between how we get information about the world and how we get information about ourselves. We have a range of external senses that inform us about the world in particular modalities: sight, sound, smell, taste, touch. This information allows us to construct virtual models of the world that are efficient for navigating the world. We have a different set of senses for the internal states of our body, many of which are not available to introspection or conscious control (e.g. blood sugar levels). Notably our mind—thoughts, feelings, emotions, etc—is an important source of information about our own internal states. 

There is some crossover, as when we gain information about our body by looking at it. But generally speaking there is a clear epistemic distinction between "in here" and "out there". Just as there is an epistemic distinction between, say, seeing light reflected from an object and hearing the physical vibrations that it makes. To my knowledge, and despite the phrase "seeing is believing", no one has ever argued that seeing is real and hearing is unreal, or vice versa. We acknowledge that both occur, that they are different modes of sensing, and give us different information. And we can always ask another person, "Did you see/hear that?" and compare notes. Problems emerge when we jump to metaphysical conclusions based on epistemic differences without first establishing whether there is some metaphysical basis for the differences. 

As far as anyone can tell, there is no mind/body dualism in the sense that they are different substances. But that said, we do have an undeniable experience of an epistemic difference between mind and body. We gain knowledge of each in different ways. One cannot introspect an external object for example. Nor can one use empathy to project the emotional disposition of a non-sentient object. When I put my cup down I don't wonder how the table will feel about it. There is no way for the table to support sentience let alone forming an opinion. 

At this point, Buddhist cite mystical experiences as evidence for their conclusions. The problem with mystical experiences, is that they are interpreted differently according to one's preferences. I have already cited the example of Gary Weber, the Advaita Vedantin. But there are also Christian mystics, for example who interpret what seem like the same experiences as evidence for the existence of God. 

Conclusion

Everyone is trying to make sense of their world. Some go about it more systematically than others. The less systematic our approach, the more likely that errors and infelicities will creep into our worldview. Early Buddhists systematically explored mental states that occur in the process of withdrawing attention from sensory experience. The results are practices that we call "meditation", a word that goes back to an Indo-European root *med and (rather appropriately) means "take appropriate measures". Early Buddhists did not systematically investigate anything else. They showed no interest in "reality" or the "nature" of reality, except insofar as it pertained to karma and rebirth, which they accepted a priori as true. 

Here we see the disadvantage of religious modes of thinking. Religieux begin reasoning from a metaphysical commitment; a belief. And recall Michael Taft's aphorism: belief is an emotion about an idea. From the belief, religieux look for evidence that is consistent with that belief and hold it up as confirmation of the belief. At the same time they overlook, ignore, or dispose of any counterfactual information. 

Religious metaphysics are not motivated by a search for the truth. Religieux invariably believe they already know the truth. This applies to Buddhists as much as any other religion. We start from certainty and then inquire as to how reality confirms our assumptions. A procedure known as confirmation bias. 

Buddhist metaphysics, of which there are several, are fine except that they disagree in every possible way with physics. Buddhists who are aware of this fact (and appalled by it) will often invoke Eugene Wigner's version of Niels Bohr's interpretation of the Schrödinger equation, i.e. "consciousness collapses the wavefunction". Back in the real world, physicists universally agree that Wigner was talking bollocks, and most of them have abandoned Copenhagen (though they continue to teach it to undergraduates). Buddhists seldom, if ever, come out in defence of other valid interpretations of the Schrödinger equation. We see no Buddhist essays arguing that, for example, Bohmian mechanics (aka pilot-wave theory) reflects the Buddha's insight. Buddhists are attracted to the deprecated Copenhagen interpretation because purely by confirmation bias. There really is no connection between the Iron Age observations of Buddhists about how their minds work and the twentieth century observations about how matter changes  over time on the nanoscale. 

That said, like other physicists, Bohm himself later went into the business of speculative metaphysics. It is a quirk of many physicist that they start to believe that they really do understand everything. There are any number of books of unscientific (but influential) nonsense from people like Eugene Wigner, Linus Pauling (Vitamin C), and including Bohm himself, and even the Venerable Albert Einstein. 

When I began to adopt an epistemic approach to Buddhism, I realised that I no longer had any conflicts with my education in the physical sciences (I majored in chemistry). 

Buddhist metaphysics as reflected in various texts across time have no advantages over any other religious metaphysics. The Buddhist worldview is always stated in such a way as to allow for the supernatural (or what I sometimes call "the unnatural"): karma, rebirth, gods, demons, spirits, heavens, hells, ESP, etc. At best these views approach the sophistication of Descartes, accepting a dualistic world in order to preserve a place for non-natural entities, forces, locations, and events. Buddhism provides us with nothing approaching the physical laws of nineteenth century science. No equivalent to, say, the universal principle of conservation of momentum.  Which is hardly surprising given that most Buddhists think the real world is "an illusion" and that a "spiritual" Reality is to be found in purely subjective mental states. Why would this approach produce any insights into the real? 

While religious Buddhists have an ongoing battle with the real, in that it clearly does not conform to Buddhist orthodoxy, I no longer have this problem. I no longer feel any tension between my scientific outlook and my Buddhist vocation based on working with my mind. They are two distinct provinces of knowledge, at least for the time being. 

Why does this matter? I think religion in Europe (and her colonies), generally, is struggling with two tendencies: the tendency towards fundamentalism and the tendency towards rationalism. The former stymies all intellectual progress, while the latter sees no value in religion. We've all watched secular mindfulness rapidly become very much more popular than religious Buddhism. We've seen many emotive arguments against practising mindfulness outside of the metaphysical commitments held by most Buddhists. How much worse will it be when we begin to see secular training in attention withdrawal (if it does not already exist) and a secular "enlightenment". That could easily eclipse European Buddhism, though my sense is that Asian Buddhism is more insulated from this kind of discourse.

Central to my faith in 2022 is this credo: I believe that sensory experience can cease without loss of basic awareness. I believe this knowledge was discovered in ancient India and became the basis for a number of religions. 

Although the result is described as "contentless awareness" those who undergo this can remember what it was like and are usually eager to offer an interpretation. To date religious explanations have dominated the field. Nascent academic attempts to characterise and categorise such phenomena are fascinating, but still lack coherence. While I mainly write for a Buddhist audience, I kind of hope that some academic will also notice my epistemic approach and see how it disentangles religious sentiments from the difficult work of identifying and characterising what is real. 

In this sense, then, I think enlightenment, awakening, liberation, purification, or whatever we call it, is a real phenomena. I feel fairly confident that I've met people who are "in that state" (tathā-gata, as we say in Pāli). And scientists are right now measuring the neural activity of people in a state of contentless awareness looking for, and finding, neural correlates of cessation and awakening. Where Buddhism and science part company is precisely where all religions breakdown, that is on the interpretation of experience, especially with respect to what experience tells us about "reality". 

Cessation is something we can systematically cultivate. The way to cultivate it is to minimise sensory experience, both in daily life and more radically in meditation. The goal of practice is a form of knowledge, not a form of existence. We call this knowledge prajñā or paragnosis, knowledge from beyond the cessation of sensory experience. Without the supernatural elements, with the view that the Buddha was talking about experience rather than reality, we can drop all the metaphysical speculation about what it all means, and arrive at a simpler, more coherent view of Buddhism, that has realistic goals for maximising human potential.  

~~oOo~~