In 2008 a group of experienced meditators sat down to a plain task: count your own heartbeats, without taking your pulse. Afterwards they were asked how it had gone. They rated their performance as better than the control group’s, and they found the task easier than the controls found it. Their actual accuracy was no better at all.

That is a real finding and it is worth having. But the more interesting question is the one nobody in the room had to ask, because the answer had already been decided for them: why heartbeats?

Two sentences that sound like one

“I am very attuned to my body” is a self-rating. “I detect my own heartbeat” is a performance. In ordinary speech they pass for the same claim, and in the data they come apart. Where both sides are measured with instruments that are stable over time — retested at .60 and .73 — the correlation between objective accuracy and self-reported body awareness is .06. That is not a weak relationship. That is no relationship.

It is not simply that people flatter themselves, either. Professional dancers do have genuinely elevated accuracy, measurably better than controls, and it still fails to line up with how they describe themselves. The two things are not the same thing.

Nobody in this field ever proposed the heart

Here is what is easy to miss. No somatic tradition has ever claimed that the skill it trains is cardiac enumeration. Not Reich, not Gendlin, not any teacher of any lineage. The heart entered this literature for one reason: it produces a discrete, countable, externally verifiable event several thousand times an hour, and almost nothing else in the interior of the body does.

That is a perfectly good reason to build a paradigm on it. It is not a reason to treat the result as a verdict on body-reading. The criterion was chosen for availability, not because anyone argued it was central — and a conclusion can only travel as far as its criterion reaches.

The measure is in worse shape than its use suggests

Since the whole edifice rests on that one task, its condition matters. In a sample of 572, over 95% of scores were under-counts, and the score turns out to be structurally tied to the participant’s own heart rate. When the instruction is tightened from “count your heartbeats” to “count only the beats you actually feel”, scores roughly halve — meaning a good share of what has been published as interoceptive accuracy was something else. Two published comments argue that part of this critique is an artefact of scoring a ratio variable; both sides accept the under-counting, and the objection about instruction wording has not been answered.

Worse for anyone wanting a clean number: counting your heartbeats and detecting your heartbeats are each internally reliable tasks that do not correlate with each other. There is no single quantity called objective interoceptive accuracy. A systematic review of the field’s own measurement situation calls high validity “potentially elusive”. And the tidy three-part model — accuracy, sensibility, awareness — is not a settled structure either: its only direct test confirmed it in part and found the answer depended on which task was used, and its own senior author moved on in 2022 to a broader framework, on the grounds that assessing those dimensions in isolation does not capture what interoception is.

So why does the dissociation still stand? Because it never depended on that task. It appears where both measures are temporally stable; it appears inside a single sample, in those meditators; and it appears where accuracy genuinely is higher, in the dancers. Demolishing the instrument does not demolish the finding — which is the test of whether a result is real.

What measurement is for is not the same in every discipline

This is our own way of sorting it rather than something taken from the literature, but it does the work that a general complaint about proxies cannot.

In engineering, measurability is the decisive factor — even though the interpretation of proxy quantities is genuinely problematic. Nothing ships on a feeling. The problem is handled by naming it, not by abandoning the measurement.

In science, measurability is also decisive, but a coherent model-based interpretive scheme is more fundamental still. A number without a model that says what the number is a measure of is not a finding; it is a reading. A literature with thousands of measurements and no model bridging its levels is not close to an answer, however precisely it measures.

In phenomenological disciplines, a hard push for measurability on proxy scales can do harm, because it obscures the thing. The available scale decides what will count as the subject, and whatever cannot be displayed on it stops being visible. That is not an argument against measuring. It is an argument about what a measurement here is evidence of. (How this site keeps measured, computed and rated apart is set out on what “measurement” means on this site.)

The failure mode, then, is narrower than “proxies are bad”. It is importing one discipline’s norms into another discipline’s question — and the cardiac literature does exactly that, running a phenomenological question under engineering rules.

And our own side is caught by the same thing

This is where it would be comfortable to say that the felt sense is too rich to be measured, and that the researchers should have come to us. That argument is not available, because it was tried.

The Experiencing Scale has been rating depth of experiencing from therapy transcripts since 1969. It is reliable in good conditions, and it works: a meta-analysis of ten studies and 406 clients finds it predicts outcome, at a magnitude of about r = 0.19 — roughly four per cent of the variance. Something in the neighbourhood of felt sense has been operationalised for sixty years.

And it fails in a structurally identical way. Treatment approach was not a moderator — it predicts outcome just as well inside CBT, and its own authors call it a probable common factor, so it is not measuring anything distinctively experiential. The strongest available critique of its construct validity found its closest correlate to be the density of first-person self-disclosing utterances: a countable feature of speech. Nobody has ever tested whether it is confounded by verbal fluency, education or class — on an instrument that rates transcripts. An independent study in 2026 found it did not change and predicted nothing, while the therapeutic alliance did. And Focusing itself, after sixty years, has no completed randomised trial at all, which is stated in print by the Gendlin Research Center rather than by any critic.

So the honest version is symmetrical, and it is stronger than the self-serving one. Cardiology measures the heart because hearts are countable. The experiential camp measures transcribed speech because speech is recordable. Neither is measuring the construct it names — and whether the absence of a solid model working in simple measurable quantities is a virtue or a failing is a side quarrel about the standing of a discipline, not about its subject.

The same shape, larger

Robert Sapolsky’s Determined (2023) argues there is no free will: every decision has neurobiological antecedents, layer under layer all the way down, and there is no crack in that chain into which freedom could be fitted. He frames his challenge as a shift of the burden of proof — show me a neuron that is a causeless cause, and you have demonstrated free will.

The flaw is in that challenge. It is not in the data but in the inference — a logical error, and therefore a scientific error of the most basic kind, because logical consistency is not something beside scientific honesty but its precondition. It is an unstated premise. Sapolsky makes causelessness the condition of freedom. Nobody defends that freedom; pure randomness is not control over one’s own action, as his opponents readily grant. The only thing that could count as free will on his terms is therefore something no one claims, and the question is settled by definition before any evidence arrives. The book gives six chapters to emergence, chaos and quantum indeterminacy — but discussing them is not the same as showing that a decision has no degree of freedom left. That randomness is not freedom is true, and it answers a question nobody asked. The step on which everything rests, from „has antecedents“ to „has no freedom“, is argued nowhere in the book. It is built into the definition and never acknowledged. That someone writes six chapters does not make the conclusions true, nor even show that the author knows what he is writing about.

To defend determinism credibly, one must not stop halfway. And if one does not stop in time, fundamental determinism is hard to defend.

What follows is our own reasoning, not taken from the free-will literature; it rests on physics that can be looked up. Determinism can be credibly asserted only where a system can be described by deterministic equations — that is, in physics. Anywhere else it enters the description only as an assumption, and an assumption is not a proof: whoever puts it in at the start finds it at the end. Whoever wants to play the deterministic game honestly must therefore go down as far as it goes, to equations of evolution that really are deterministic. The only road there is consistent reduction — from behaviour to tissue, from tissue to cells, from cells to molecules.

And there one hits a wall, twice. First, complexity: the quantum description of molecules rests on the Schrödinger equation, which is deterministic but which we cannot solve in full. Bedřich Velický recalls Dirac’s remark of 1929 that the fundamental laws for most of physics and all of chemistry are completely known, and the only difficulty is that their exact application leads to equations too complex to be solved (Velický 2016, pp. 184–185; our rendering); in a footnote he works out that the wave function of a single water molecule would occupy on the order of 1039 petabytes. Everything we know about molecules is therefore an approximation — of solid-state physics he writes that the solutions of its equations are „admittedly approximate“ (p. 12; our rendering). Second, chance: even if the evolution were fully deterministic, what we call the classical world arises only where a system is separated from its environment — and the result of that separation, the result of measurement, is random by nature. Roger Penrose, among others, has pointed this out; and one meets it every time a description is split into system and surroundings, whether the boundary is molecular, cellular or tissue-level. What that descent looks like when a physicist leads it is shown in Pavel Krtouš’s lecture Free Will in a Deterministic Prison (in Czech) from the seminar Philosophical Problems of Physics at the Faculty of Mathematics and Physics, Charles University (2021).

Whoever follows the best current knowledge consistently therefore faces a question the book does not answer: how can full determinism be defended at the level of behaviour, when the description of that level hangs on many storeys of approximation and, beneath them, on decoherence that is random? A reasonable partial model of a complex system can say a great deal that is useful. It cannot yield a strong statement about the nature of that system — and „you have no free will“ is a statement about its nature.

David Bentley Hart put it more sharply. The book’s science, he says, is up to date and worth reading, but its argumentation contains basic logical errors on essentially every page; he arrived there by way of Libet’s experiments of the 1970s, in which, on his account, the mechanistic assumption was built into the method, so the reading of the results was decided in advance. It was said in passing, in about two minutes of a conversation with Philip Ball from March 2024 (the passage begins around 0:56:16); we do not give the exact wording until it has been checked against the recording, and refer the reader to it directly. None of that changes the weight of the objection: it holds not because of where it was said but because it fits the text — and the reading of the definition above is one anyone can repeat. Hart is not a libertarian about free will; he thinks that model is nonsense. His quarrel is with mechanism raised to metaphysics: with deciding a question about intention and reason under the rules of a discipline that can measure antecedents.

It is the same transfer error as with the heartbeats, at the level where the concept of a person is at stake.

And the direction the argument must not run

In the 1980s a chain of reasoning looked airtight: ventricular arrhythmias after a heart attack predict sudden death; encainide and flecainide suppress them; therefore they will save lives. The criterion — arrhythmias on a Holter recording — was chosen because it was objective, measurable and quickly available. The phenomenon was survival.

The trial found 56 deaths in 730 patients on the drugs against 22 in 725 on placebo. The drugs did exactly what the surrogate measured, and killed people. The authors of the final report state that the mechanism of the excess mortality remains unknown — which is the part that matters: the proxy’s failure was demonstrated before it was explained. Refusing measurement out of respect for the richness of the phenomenon would not have produced that knowledge. Nothing would have.

So this is not a case for measuring less. It is a case for knowing which question is being asked.

What actually follows

The narrow finding stands and is worth keeping. Confidence in a reading is not evidence of the reading — for the client who says they are very in touch with their body, and equally for the practitioner who is certain about what they are sensing in the room. Those meditators were not lying and were not careless. They were confident, and confidence was uninformative.

Years of practice are not a credential for accuracy. They may be a credential for steadiness, for tolerance of difficult states, for staying present with another person — and those are not nothing. They are simply not the same as reading the body more correctly, and this field lets the first stand in for the second.

One more thing needs saying, so that the word accurate does not stay with measurement alone. Therapeutic practice speaks of precision too, in another sense. Hakomi looks for the precisely resonant probe — the sentence that sets something ringing in the client, and not the one a word away. Focusing looks for the word that “fits” the felt sense, and the body itself knows when it does not. That precision cannot be expressed as a correlation. It is a far finer play with language than technical measurement conducts, and the two metaphors overlap only in part. The heartbeat study says nothing about it — and neither does this text. (This paragraph is our own reading, not a finding of the study.)

What does not follow is that the cardiac result is the verdict on body-reading. It is a verdict on heartbeat counting, which nobody here ever claimed was the skill.

The evidence, including what stands against all of this, is on the What We Know, and How Well page — sources named, gaps marked as gaps.