Posts Tagged ‘causality’

Materia Prima

10 December 2012


The Beginning of the End
So this is it for me and Bernard d’Espagnat’s On Physics and Philosophy.

In the final chapter d’Espagnat allows himself to speculate on the philosophical and spiritual importance of his veiled reality (which he capitalizes) in particular, and the results of modern physics in general.

The chapter is entitled “The Ground of Things.”

It is in these concluding sections that d’Espagnat makes his final defence of a materia prima, a mind-independent reality, before the objections of both realists (who concentrate on empirical reality) and antirealists (who say mind is all).

Some of those arguments say there’s no reality-in-itself, some say it exists but is inaccessible, and others say empirical reality is “reality.”

Kant vs d’Espagnat
D’Espagnat believes “the Real” is a mystery as it is (in his opinion) not accessible through discursive knowledge.

He notes Immanuel Kant distinguished between phenomena and “reality-in-itself,” but disagrees with Kant that a mind-independent reality is just a boring “limiting concept” filled with “pure x.”

Cassirer vs d’Espagnat
Ernest Cassirer strongly objected to being content with a “mystery,” which he felt would be an unbearable block to scientific inquiry.

D’Espagnat says when possible the search for clarity is admirable, but the true spirit of science is to follow where the facts lead it.

The quantum entanglement shown in “Aspect-like experiments” (by Alain Aspect and others) are just part of our evolving scientific knowledge.

Materialists vs Mystics
Sometimes one should approach “mystery” the way mystics, poets, or composers have done so (though more often in the past).

Realists (materialists) have no reason to believe they hold all the keys to knowledge, even in principle.

As for the antirealists (and instrumentalists), if they think reality is something we ourselves build up, then mystery can hardly be called an exceptional “illusion.”

Affect vs Effect
The “affective” element of human existence is an aspect that seems to circumvent our rationality.

Kant felt the “affective mind” was not “ordered on concepts” and therefore could shine no light on Being.

D’Espagnat is more sympathetic to Descartes. Thought leads to the self-evidence of existence (“I think, therefore I am”), but d’Espagnat says just as self-evident will be our “joys and pains.”

We base our conjectures on what we know most intimately, and what could be closer to us than our “affective consciousness”?

This too should be able to inform us of Being, perhaps in some circumstances even better than science can.

Realism vs “the Real”
We can take a very realist position and imagine that if mankind disappeared the stars would continue in their courses.

This is an argument for a mind-independent reality—just not the one d’Espagnat has in mind.

D’Espagnat says just because our present existence is usually most conveniently described in realist terms (such as conventional space and time) doesn’t mean the realist position is actually true.

Even particle physicists who use the realist language of minuscule points and well-defined trajectories know that’s not what’s “really” going on.

Radical Idealism vs “the Real”
On the other hand radical idealism believes there is no reality outside the mind.

In other words, there’s no mind-independent reality.

D’Espagnat says his earlier arguments, either based on no miracles or intersubjective agreement (see chapter five) undermine idealism but not his veiled reality position.

Mathematical Realism vs “the Real”
Whether it’s “Pythagorism” or “Mathematical Platonism” there’s a belief that mathematical developments are discovered not created.

Again, this would be a mind-independent reality, but mathematically based.

Physical reality is either grounded on a pre-existing mathematical reality or there’s some strong connection between the two.

D’Espagnat reminds us that quantum formalism refers to observational predictions.

It’s possible “the Real” is mathematically based, but quantum theory isn’t going to get you there.

Brains in a Vat vs “the Real”
D’Espagnat disagrees with Hilary Putnam’s thought experiment that places brains in vats.

Connect electrodes to the brains and some supersmart being could send (in theory) images and other sensations directly to the brain.

Putnam says a vat individual could not truthfully say, “We are brains in a vat.”

That’s because his concept of a vat is based on an illusion.

So there’s no connection between this particular version of a “ground of being” and our knowledge.

D’Espagnat disagrees with the assumption that knowledge springs only from the senses.

Also, Putnam’s imaginary statement refers to specific entities. D’Espagnat’s concept of “the Real” is “conceptually prior to any such description.”

Self-Modification vs “the Real”
Francisco Varela and collaborators proposed “enaction” theory.

The brain’s main function is to modify its internal states rather than reflect the external world.

External reality is neither a projection of our mind’s contents nor the source of those contents.

There’s no need to imagine a “pre-given” reality.

D’Espagnat faults Varela’s book for vague terminology.

Does Varela mean “empirical reality” or “mind-independent reality” when he talks of “reality”?

Is the “subjective” an individual’s subjectivity or intersubjectivity?

D’Espagnat disagrees with Varela’s use of “secondary qualities” such as colour to make his arguments.

Even Varela’s arguments about attention and perception fail to convince d’Espagnat.

The mind may display selective attention but that’s a far cry from proving that mind and world somehow arise together.

Structure vs “the Real”
Some people say there’s no reality-in-itself, some say it exists but is inaccessible, and others say empirical reality is “reality.”

D’Espagnat says arguments against veiled reality will fail if they’re based on discursive (descriptive and rational) knowledge.

In other words, arguments based on what structures we see or don’t see are irrelevant to “the Real” as “the Real” doesn’t have structures in the way we’re accustomed to think of them.

Buddhism vs d’Espagnat
D’Espagnat notes Varela’s frequent references to Buddhism.

Buddhism speaks of “sunyata” or “emptiness” in rejecting objects in the world as intrinsically existing in the way we perceive them.

Furthermore our living “selves” have no absolute existence as individuals.

D’Espagnat hopes his veiled reality viewpoint will interest Buddhists, especially as there’s a pretty thick veil between consciousness and “the Real.”

Heisenberg vs “the Real”
D’Espagnat rejects Werner Heisenberg’s (posthumously published) view that empirical reality is a product of our human-made knowledge.

Heisenberg felt there were various “regions of reality” such that our knowledge of biology, for instance, weren’t entirely dependent on our knowledge of physics.

Heisenberg did think there might be something that’s “truly real,” vaguely reflected upon human consciousness.

However, he felt this level of reality would still be situated within ordinary space and time.

It’s on that count that d’Espagnat rejects Heisenberg’s arguments as irrelevant as “the Real” is not located in space and time.

Pro vs Con
In the end Heisenberg finds arguments both for and against a “ground of things” dubious.

You can argue against a “ground of things” but only in the sense of a “pregiven,” describable “world-per-se.”

D’Espagnat finds the “pro” arguments based on “commonsense” or a pre-existing mathematical reality also unconvincing.

D’Espagnat believes a “more fact-based reasoning” is called for.

Universality vs Events
D’Espagnat says over the past half-century interest in chaos and complexity led some scientists to demote scientific laws and promote the role of the “event,” previously seen as more or less accidental.

He says he argued against rejecting the “universal” in a 1990 book.

He’s more ambivalent about the emphasis on “events,” which he says takes place within empirical reality.

That reflects the way we’re “apprehending the Real” but doesn’t meant that’s what “the Real” is all about.

For instance, we don’t see objects as nonseparable, but that’s what quantum theory tells us.

D’Espagnat says Edgar Morin and others in this school of thought have somewhat retreated from their emphasis on events, complexity, and disorder.

Morin acknowledges that “Aspect-type” experimental results have shown some limitations in his approach.

Nominalism vs “the Real”
D’Espagnat is unimpressed with the revival of nominalism among “cultivated, literary, avant-garde people.”

It’s a belief system promoted in the Middle Ages by William of Ockham and others.

Nominalists nowadays reject the universal while applauding individual initiative, which they feel is a product of individual knowledge.

The problem is that nominalism is an all-encompassing philosophy, referring to all things, not just living beings.

The discrete atoms of classical physics have given way to “collective modes of existence.”

And again such arguments apply to empirical reality not “the Real.”

D’Espagnat vs the “Enlightenment”
D’Espagnat believes many sophisticated members of society are still enthralled by outmoded ideas of the “Enlightenment” (d’Espagnat’s quotes).

D’Espagnat acknowledges that research on chaos and events may eventually back nominalism.

However, he things quantum theory and inseparability will win out.

Spinoza vs “the Real”
D’Espagnat cautions against thinking Spinoza was a committed materialist when he talked of “God, in other words, nature.”

Although Spinoza’s natura naturans sounds like “the Real,” his natura naturata sounds like phenomena.

D’Espagnat does not agree there’s a willful, personal God behind all this, however.

Veiled reality is not “intelligible,” unlike Spinoza’s view of Substance.

Phenomenology vs “the Real”
Classical physics introduced mechanical, then mathematical, idealizations of objects.

How things supposedly “really are” became separated from our “direct experience.”

Quantum theory reintroduced a role for the human mind to account for our experiences.

In some ways quantum theories reinforces phenomenology.

Phenomenology sees an act of creativity in the human mind.

It takes various pieces of sensation and constructs some entity that shares these qualities.

However, on some level the source of these sensations still independently exists.

Quantum theory states that some physical quantities can only be observed through human intervention, thus undermining phenomenology’s belief in independently existing sources of phenomenon.

Modern “Sages” vs “the Real”
In “developed” societies there are “sages” who take rather contradictory views.

They say there is a reality independent of us.

But they also say it’s “obvious” we rely on our perceptions to gain access to that world.

So they conclude it is illogical to speak of an “unreachable” reality.

We should make only statements relying on sense data or tautologies (statements that are always logically true).

However, d’Espagnat continues to oppose the view that our perceptions necessarily reflect reality as it really is.

Our modern “sages” try to combine realism and positivism, converting “reality-per-se” into “observation-per-se.”

But there is no “observation-per-se” as observations involve human intention and selection.

The Describable vs “the Real”
If we reject the materialists’ rejection of “the Real,” does that force us into the camp of the radical idealists?

D’Espagnat says we shouldn’t confuse “the Real” and “the describable.”

First, existence takes precedence over knowledge.

Secondly, there is something that says “no” to any arbitrary constructions of reality.

Third, it’s hard to imagine an “a priori” that evolves.

And fourthly, there are universal laws that make predictions, and it’s hard to envision how laws could do so unless you believe in miracles.

Even Michel Bitbol and Hervé Zwirn have not entirely rejected the concept of “the Real” even as they critique it.

D’Espagnat says thinkers should avoid pushing deductive reasoning into areas where it may not strictly apply.

As a sidenote, d’Espagnat says classical instrumentalism believes a concept’s meaning and “reference,” the collection of data about the concept, are the same.

Even if you replace “data” with “prediction” it’s not a universal position as predictions require a predictor.

And that predictor is some being who’s doing the predicting.

Laws vs “the Real”
Bitbol and Zwirn may move a bit toward Platonism when they acknowledge something may constrain us that is not entirely attributable to us.

However, they believe this “something” is totally inaccessible.

D’Espagnat disagrees, and thinks Plato would disagree too.

“The Real” must have some influence on empirical reality’s structure as Maxwell’s laws (for instance) are obeyed by phenomena.

D’Espagnat’s “extended causality” links not instances of phenomena but rather phenomena and “the Real.”

These structural “extended causes” move beyond Kantian causality and recall Plato’s Ideas.

Structures vs Hints of Structures
D’Espagnat says “the Real” is prior to mind-matter splitting, so the mind may detect hints of the mind’s source, which is “the Real.”

That veiled reality is not the same as the underlying reality described by structural realism.

D’Espagnat says mind-independent reality is not the source of our physical laws. At best these laws are distortions of the “great structures” of “the Real.” At worst they’re just very obscure “traces.”

In the end “the Real” isn’t describable, indescribable, or party describable.

The first two options imply a total presence or lack of description, and the third option implies “the Real” has parts, which isn’t the case, says d’Espagnat.

Conceptualization vs Meaning
If “the Real” can’t be conceptualized can it have any “meaning”?

D’Espagnat cites Zwirn’s argument imagining a creature as far ahead of humans as humans are ahead of dogs or monkeys.

We can conceptualize things that dogs or monkeys can’t, so surely a superhuman being could conceptualize things we can’t.

D’Espagnat believes that poets can allude to things that we somehow know exists even if these concepts can’t be made explicit.

Plato’s Cave vs “the Real”
At first glance Plato’s Cave approximates d’Espagnat’s view of veiled reality.

It suggests the emergence of (shadowy) empirical reality (seen in the cave) from “the Real” (the porters who place their Platonic Ideas in front of the light).

However, the fable doesn’t deal with how consciousness (the prisoners) would have emerged from “the Real.”

Furthermore, “the Real” cannot be separated into parts (while the porters hold separate objects).

We cannot conceptualize “the Real” yet Plato conceptualized his Ideas.

Finally, even without prisoners there’d still be the shadows, while in d’Espagnat’s system phenomena would exist only in relation to consciousness.

Traditional Thought vs “the Real”
D’Espagnat warns against a syncretism of old cultural elements and new philosophical points, but he wonders if “the Real” has any bearing on traditional systems.

Religions speak of an “immorality,” which suggests some absolute time that physics no longer can support.

However, perhaps the other term “eternity” suggests escaping this illusory time.

And perhaps there is a “continuous creation” of Being in a process independent of time.

Heisenberg vs d’Espagnat
Heisenberg, says d’Espagnat, doubted thought could illuminate deep matters as (according to Heisenberg) thought returns to its source.

But d’Espagnat notes that new science has allowed us to move past old science’s viewpoints, such as materialism.

So thought has been able to illuminate some deep matters.

Platonism vs d’Espagnat
D’Espagnat sees similarities between his view of causality and Aristotle’s.

Aristotle was a realist and was concerned with causality not just in the realm of phenomena but in “reality-in-itself.”

Furthermore, Aristotle was not beholden to the idea that causes precede effects.

Instead there could be “final causes” to which things might tend under the influence of Aristotle’s God.

As d’Espagnat’s veiled reality is beyond time, “the Real” could impart such a “final cause” on empirical reality.

Also, Aristotle’s interest in causation beyond mere phenomena reminds d’Espagnat of his own interest in causation between “the Real” and empirical reality.

Aristotle distinguished between “power” and “act” while Newton supposedly saw just “act.”

Aristotle saw matter as the seat of a vague potentiality.

Materia prima is pure potentiality.

“Informed matter” exists on more and more complex levels. Simple beings can be the “matter” for more complex beings.

These complex beings in this process are more “real” as their potentiality is expressed.

Therefore the deep meaning of reality lies not in the tiny components of complex beings, but rather the meaning is the complex beings themselves.

In a similar fashion, in empirical reality the wave functions have an “epistemological reality” at a lower level than, say, macroscopic objects in the wake of decoherence.

Although Heisenberg did not cite decoherence he did ponder the possible role of wave functions as a “materia prima.” Abner Shimony went on exploring this issue.

However, they’ve both admitted it’s hard to formulate these ideas precisely.

Plato vs d’Espagnat
As for Plato, d’Espagnat reminds us of his earlier concerns about the Plato’s Cave.

However, for Plato the deeper meaning was not in the things themselves.

They didn’t reside just in “us” either. He wasn’t a radical idealist.

Platonic Ideas (and his concept of the “Good”) bear resemblance to “the Real.”

However, Platonic Ideas are conceptualizable while “the Real” is not.

Many scientists believe, still, that analyzing more and more sense data will get us closer to the deeper meaning of reality.

However, advances in science have relied on a “rapprochement” between science and a philosophical position (Platonism) that questions such a program.

D’Espagnat notes that “Platonism” is a term nowadays often interpreted as “Pythagorism” with real mathematical objects.

D’Espagnat does not agree with “Pythagorism,” but notes that there’s some relationship between it and Platonism.

Even veiled reality has a smidgeon of Pythagorism in it as empirical reality’s objects are somehow a dim reflection of “the Real.”

Einstein vs d’Espagnat
Albert Einstein appears to have believed “the Real” could in principle be apprehended in its details, even if in practice that was rarely possible.

However, the goal remained to explore this deeper world by discovering universal laws.

Einstein also believed in three levels of religious experience.

The first was based on fear, the second morals, and the third transcends ordinary human views of God.

At this third level, Einstein thought, a sublime order is reflected in nature and in thought.

Even scientific materialists no longer believe the common materialism that the mass media disseminates.

However, there have also been developments that make us question some of Einstein’s philosophical positions.

D’Espagnat sees some compatibility between his views and Einstein’s even if Pythagorism doesn’t have to be entirely correct.

“The Real” does not have to be totally intelligible.

The human mind may tend toward the structures and qualities of “the Real” in the sense that Max Planck had a strong affective experience in his theoretical work.

It’s not necessary that mathematics reveals everything about “the Real.”

Rather, as long as we have some concept of “the Real” that we can tend to, the structures and qualities of the mind may be drawn to it even as it never fully understands it due to the mind’s limitations.

The Spiritual vs the Scientific
Maybe this idea is closer to Einstein’s third-level religious experience rather than a completely knowable “Real.”

The human mind tends to quest and exploration, though never able to fully accomplish what it desires.

Einstein was still grounded in physical materialism.

Later developments in physics have shown us something more human-oriented. We can’t limit Being to just material components.

The mind may somehow “recall” aspects of Being as consciousness is not just a product of matter.

Archetypes of some of our feelings may lie with “the Real.” There’s no way to prove this, or disprove this.

But crucially we can no longer see science as an impediment to the “spiritual impetus that moves mankind,” an impetus, according to Einstein, that makes us desire to live “the whole of what is.”

And it is an impetus that possesses both unity and meaning.

Making an Appearance

8 December 2012


Mind the Details
Bernard d’Espagnat delves into finer and finer distinctions between his veiled reality position and similar (though not identical) views.

The eighteenth chapter of his On Physics and Philosophy is entitled “Objects and Philosophy,” and there’s only one chapter to go after this.

Philosophers vs Consciousness Researchers
D’Espagnat says he takes mostly a philosophical approach in this book.

Philosophers question the basis of our reality while consciousness researchers (such as neurologists) take physical realism as a given (whether they’re conscious of this or not).

Mind vs Reality
Radical idealists, who think mind is “primeval,” may wonder about the relationship between mind and “basic reality.”

Supporters of d’Espagnat’s “veiled reality” or “open realism” approach are even more motivated to investigate.

Truth vs Reality
A physical realist can say that a true statement is “adequate to what reality really is.”

This is the “similitude theory” of truth.

Reality vs Representations
But if we don’t have access to reality as it “really is” then we might say we have access only to “human representations” of “the Real.”

Instead of worrying about whether statements are true to reality you might worry more about the verifiability of statements.

Knowable vs Unknowable Reality
Another problem with the “similitude” approach is that quantum mechanics, the best model of the world we have, fundamentally deals with observational probabilities not plain and simple facts.

Even resorting to a Broglie-Bohm approach doesn’t help as “hidden variables” will be inaccessible to the observer even in principle.

Idealism vs Veiled Reality
A radical idealist or Kantian rejects the similitude approach anyway.

A supporter of the veiled reality approach has to take a somewhat nuanced tact.

Very broad statements about physical constants or “existences prior to knowledge” may hint at “the Real” without claiming to say anything directly about “the Real” as it “really is.”

Appearances vs Veiled Reality
If we’re not supposed to trust in “appearances” then what is reality really like?

We might think that “the Real” is just an updated version of “appearances.”

Or maybe mind-independent reality is so independent that it’s entirely inaccessible.

D’Espagnat says both approaches are too extreme.

Causal Links vs Predictive Laws
We like our ordinary, everyday version of “realism” because it lets us imagine particular cause-and-effect relationships.

It’s easier to explain things when we can point to particular causes rather than just patterns of observational predictions.

D’Espagnat says some causal links are genuine and independent of us, but our interpretation of these links is very much our own.

For instance, causality is closely related in our minds to the notion of “will,” which entails a very anthropomorphic (human-centred) view of reality.

Intersubjective Agreement vs Appearances
But what if a group of humans (and maybe even non-humans!) agree on certain observations?

D’Espagnat says that this agreement combined with rules of observational prediction mean this is our “reality.”

Saying they’re just “appearances” is misleading. It’s a kind of “reality.”

However, modern physics reminds us that humans tend to “reify” (think of the world as a set of objects).

So we still have to keep in mind that empirical reality is not the same as “the Real.”

Empirical Reality vs Mind-Independent Reality
Although d’Espagnat is comfortable with the term “reality” to describe our empirical reality, he says we have to remember these are two “orders” or “levels” of reality.

Empirical reality isn’t just a mere variant on “the Real.”

Identity Theory vs Efflorescence Theory
In some of the more nuanced sections of the chapter d’Espagnat makes a distinction between identity theory and efflorescence theory.

Identity theory states that a genuine sensation or awareness (perhaps even thought in general) is traceable to neurons or their components.

The material aspect of these neurons is the ultimate cause of our sensations.

Efflorescence theory attributes sensations and awareness to “neuronal activity” rather than the material aspects of neurons or their components.

Strong vs Weak Completeness
D’Espagnat’s main line of attack against identity theory is the completeness principle.

In its strong version, quantum mechanics is assumed to be able to describe anything at all.

In its weak version, if any theory can describe something then quantum mechanics can do so as well. This leaves open the concept of hidden variables.

Since quantum mechanics is antirealist it’s hard to imagine how the strong completeness principle is compatible with identity theory.

Even if you take the weak version of the completeness principle all you can conclude is that the identity theory may be true—but we can never show it to be so.

But what if you reject the completeness principle entirely?

If you used the Broglie-Bohm model you’d still have to deal with an entangled wave function, so sensations can’t be attributed just to some limited coordinates of a particular neuron.

Or you can take the Roger Penrose approach by adding nonlinear terms to the Schrödinger equation.

D’Espagnat says that approach may work, but he finds it too ad hoc. It’s also work still at an early stage, yet to face the scrutiny a full theory would need to endure.

Brain vs Neuron States
Now, efflorescence theory relies on neuronal activity not the material aspects of neurons to explain sensation, awareness, and (perhaps) thought itself.

But neurologists believe brain states not neuronal states are what drives awareness. You can’t pinpoint a particular neuron or group of neurons that are responsible.

It’s the collective action spread across the brain that is associated with awareness.

D’Espagnat notes the parallel to quantum entanglement.

Protomentality vs Mentality
Alfred North Whitehead and other thinkers in the past have wondered if simple organisms or even inorganic entities can have awareness?

Abner Shimony’s “potentiality” might satisfy some objections to this concept of protomentality.

Various entities have the potentiality of consciousness, but this potentiality isn’t actualized unless a nervous system is present.

Consciousness vs Components of Consciousness
As a final objection to the efflorescence theory, d’Espagnat says that any component we cite will be part of our empirical reality.

Empirical reality depends on our consciousness.

Therefore how can something that depends on our consciousness be the cause of our consciousness?

D’Espagnat vs The “Received” View
The “received” view that thought is produced by matter is, according to d’Espagnat, “slightly useful” as a model but must be rejected as a plausible philosophical stance.

Relative Quantum States vs Relative Consciousness
Because the observer decides what to measure and how, quantum states are “relative” to these procedures.

However, some quantum rules may be considered “in isolation.” They’re not predictive observational rules and hence don’t involve probability.

They’re more like descriptions.

However, to understand the quantum world you have to consider all quantum rules not just pick and choose the non-probabilistic ones.

D’Espagnat says states of consciousness are somewhat similar.

Definite vs Indefinite States of Consciousness
Imagine a sealed-off laboratory. Paul makes a measurement. His state of consciousness is definite but Peter doesn’t know that until Paul, say, phones him with the measurement.

This is a version of Wigner’s friend, and can be extended over and over again, with an observer outside a sealed room, which contains an observer outside a sealed room, etc.

Peter thinks Paul’s state of consciousness is not just unknown (before the phone call) but also undefined. It’s a superposition of possible results (pointer values, for instance).

Yet once Paul makes the measurement, Paul’s state of consciousness is definite from Paul’s point of view.

Consciousness vs The Absolute
This apparent conflict doesn’t change the fact that physics is all about predicting observations, says d’Espagnat.

However, there’s a related issue.

We shouldn’t think that “predictive states of consciousness” are like some Absolute or can even be a substitute for the Absolute.

Quantum states are relative, and so are states of consciousness.

More precisely, states of consciousness that are predictive are relative.

Physical vs Mental
So we see some sort of “solidarity” between the physical and the mental, but that doesn’t mean the mental can be reduced to the physical.

Wigner’s Friends vs Ultimate Reality
The series of “Wigner’s friends” who occupy increasingly large rooms is suggestive of an ultimate reality that we cannot gain access to. Wigner’s friends don’t have access to the overall wave function.

Predictive vs Non-Predictive Consciousness
However, nothing prevents us from pondering non-predictive states of consciousness.

When Paul makes the observation, his state of consciousness becomes well-defined. It’s no longer predictive.

Veiled Reality vs Co-Emergence
Michel Bitbol, Hervé Zwirn, and other authors speak of thought and empirical reality “co-emerging” at the same time.

It’s a “self-qualifying” process by which structure emerges from an initial and total lack of structure.

D’Espagnat says his veiled reality viewpoint has an “ultimate ground” endowed with general structures even if they are “far from being knowable.”

This ultimate ground may form the basis for not just scientific laws but also creative and mystical endeavours.

Emergence vs Non-Emergence
So, according to d’Espagnat, structures emerge but don’t co-emerge. They pre-exist.

Co-emergence serves merely to connect consciousness and empirical (not ultimate) reality.

D’Espagnat acknowledges that in the past he has talked of consciousness and empirical reality existing “in virtue of one another.”

This does not mean that empirical reality emerged from consciousness.

Furthermore, these words are meant to be evocative rather than a precise philosophical statement.

He reiterates the impossibility of appearances, which depend on consciousness, somehow creating consciousness.

Indexed vs Non-Indexed States of Consciousness
Adopting Bitbol’s terminology, d’Espagnat says some beings may possess non-indexed states of consciousness.

That means these states of consciousness are not relative to any particular experimental setup.

However, these states of consciousness must therefore be non-predictive.

Microscopic vs Macroscopic
An idealized miniature version of a being would be too small to interact with the environment to become predictive.

In the intermediate state between microscopic and macroscopic, such beings could accurately predict one class of observations but would wrongly predict another class of observations.

For macroscopic beings that first class of observations would still be correctly predictable but the second class of observations would be essentially impossible.

These practical observations are conveniently describable in realist language, while the practically impossible observations are not.

So if we want to talk about co-emergence then we should imagine the co-emergence of “public and predictive” states of consciousness and empirical, physical reality.

This co-emergence is constrained by the class of observations that macroscopic beings can perform.

Co-emergence draws from a mind-independent reality that presumably, according to d’Espagnat, is beyond intersubjective description.

And returning to the idea of potentiality, d’Espagnat says that in moving from the microscopic to the macroscopic the “ontological potentiality” of consciousness becomes empirical actuality.

“The Real” is not in itself thought, but can give rise to thought.

One World vs Many Egos
There appears to be one universe but many minds.

Radical idealists have trouble reconciling this situation.

Schrödinger calls this the “arithmetical paradox” and proposed two solutions.

There’s “Leibniz’ fearful doctrine of monads,” and there’s the belief the multiplicity is only apparent.

Schrödinger preferred the second approach, akin to the Upanishads, which states there is unity behind the illusion.

Veiled Reality vs Radical Idealism
The multiple-room experimental setup showed that predictive states of consciousness are relative.

It’s hard to see how all those observers could be part of just one mind.

However, perhaps various observers are making mutually compatible observations, calculable using the general Born rule.

This is the same as one observer making simultaneous measurements.

This sounds compatible with Schrödinger’s viewpoint.

However, that doesn’t solve the problem of the observer in that sealed-off inner room.

It also doesn’t take decoherence into account.

On the other hand, this decoherence also hides any theoretical possibility of discovering contradictions between multiple minds and the quantum structure of physical laws.

D’Espagnat thinks more work needs to be done on this issue.

Traces of the Real

18 November 2012

Traces of Reality

The Process of Elimination
Bernard d’Espagnat gets ever deeper into familiar, and largely friendly, territory.

It’s a chapter about large agreements and small disagreements as these particular critics seem to agree as much as disagree with him.

His major challengers and comrades will be Michel Bitbol and (less prominently) Hervé Zwirn.

Form vs Content
D’Espagnat first examines Bitbol’s “verbal issues” and questions about d’Espagnat’s logical arguments.

Then he moves on to more substantive issues.

Veiled Reality vs Dualism
Bitbol suspects “Veiled Reality” is dualistic.

Classically dualism means there’s mind and there’s matter, though even in Descartes’ time philosophers puzzled how the two could interact.

Materialists later on would say mind is just a manifestation of matter, but d’Espagnot says Bitbol isn’t a materialist.

D’Espagnat says if Bitbol’s objection is about interactions then he’s got it wrong.

D’Espagnot says he doesn’t believe mind and matter are the building blocks of “reality as it really is.”

Instead mind and matter emerge from the ground reality, an “Independent Reality.”

Coming from the same source mind and matter aren’t fundamentally split from each other.

“Veiled Reality” vs Veiled Reality
Next is the issue of whether the term “Veiled Reality” is misleading.

Although d’Espagnat admits the term might suggest a world of objects behind some veil, he said it’s just simply hard to compress the concept into two words.

He admits he used to prefer a “non-watered-down structural realism,” but since then he’s undergone an “evolution” rather than a “revolution.”

Objectivist Language vs Objectivist Philosophy
D’Espagnat says it’s convenient to talk about an instrument dial pointing to a particular spot.

But objectivist language is a matter of convenience, it’s not to taken literally.

D’Espagnat uses that kind of language to talk about “impressions,” not events independent of “the existence of thought.”

In any event, it seems Bitbol acknowledged the misinterpretation and moved on.

D’Espagnat’s approach is an “essentially negative approach” of showing what capital-R “Reality” can’t be: plural, atomistic, embedded in space-time, for instance.

He says Bitbol eventually realized this about d’Espagnat’s position.

Broglie-Bohm vs Dualism
D’Espagnat says the Broglie-Bohm models are logically consistent and follow a mostly “classically dualistic conception.”

But the subject still isn’t “face to face” with the world as there are hidden variables and a “Universal nonseparable wave function.”

Hence Broglie-Bohm isn’t a fully classical dualism.

“A Priori” Dualism vs Observed Dualism
Kant used “a priori” arguments to support his “thing-in-itself.”

But can we use the data of modern physics instead as d’Espagnat has done?

Bitbol said d’Espagnat based his arguments not on quantum mechanics in general.

Rather he based it on a particular interpretation, one that rejects hidden variables.

D’Espagnat says he’s made no secret of that.

Science chooses among various explanations and tends to be wary of “an all-powerful Zeus, for example.”

Bitbol calls these factors “ampliative” criteria.

And even Bitbol acknowledges that Bohm’s theories lead to a “crisis in atomism” with their “nonlocality and contextuality.”

D’Espagnat says nonlocality doesn’t force the “thing-in-itself” to be inaccessible.

But it undermines the hope that “the Real” can be progressively unveiled.

Knowledge Of vs Knowledge About
Bitbol complained that d’Espagnat’s book Veiled Reality talked about “Independent Reality” as “something.”

But wouldn’t that make this supposedly independent reality an empirical reality?

D’Espagnat says he was careful to say the data would have “something to do” with this reality.

It would be knowledge about this reality, but not knowledge of this reality.

To Sketch vs Not to Sketch
Bitbol says Kantian and neo-Kantian philosophers would object to the idea that an “Independent Reality” is “prestructed.”

D’Espagnat says Bitbol needs to do more than just cite possible objectors.

He needs to present an actual argument.

Bitbol says d’Espagnat is implying observed phenomena lets one “sketch” various features of “Independent Reality.”

D’Espagnat says that to talk about sketching is misleading.

By giving up on the “locality principle” he’s also giving up on “sketching” Independent Reality.

Nonetheless d’Espagnat acknowledges that it’s not just a process of elimination.

He does conjecture that observational data may “in a distorted and incomprehensible way” somehow reflect some structures of “the Real.”

Reflected Reality vs Reflected Thought
Bitbol wonders if maybe predictive laws should be considered “distorted reflections” of our own mental contributions rather than of some “Independent Reality.”

D’Espagnat says it’s important to distinguish between what’s sufficient and what’s necessary.

Of course “our perceptive” context is important, but probably not enough to produce those perceptions.

Furthermore, anyone can come up with an interesting principle and follow its consequences.

One can choose to believe all connections between perception and reality are illusory.

But that doesn’t mean you’ve proved your case.

In the end d’Espagnat remains confident of his “prestructure” hypothesis, though it’s “but a plausible and admittedly unverifiable conjecture.”

Evidence vs Other Factors
Bitbol and Zwirn also wondered if one theory could be replaced by another for reasons other than evidence.

D’Espagnat replies that you can’t tweak a “realist local theory” and make it work.

Nonlocality isn’t nudging one theory out of the way—it’s demanding a different theory.

If Zwirn and Bitbol believe perceptions come solely from us, then we could believe in an experimentally refuted theory.

This may be somehow “rational” but a scientist won’t follow such a path that undermines “science and empirical knowledge in general.”

Bitbol proposes some kind of transformation groups that would explain our sensory data’s “structural invariants.”

D’Espagnat thinks the analogy from group theory is inexact.

In any event, it’s not particularly interesting that nonlocality could appear in some “acceptable realist theory.”

What’s important is that it tells us we can never use a local realist theory to explain all of our observed data.

Nonseparability vs Unity
D’Espagnat admits he went too far in saying the nonseparability of Independent Reality implies some kind of unity in that Independent Reality.

He agrees with Bitbol that this statement demands a principle of the excluded middle such that rational categories cover all that is possible.

The transcendent may not be so intelligible.

Instead of Plotinus’s “One” we should think of a unity that is “the absolutely inexpressible” (pantè aporeton).

This view is still consistent with the (unprovable) view that “poetry, music, painting etc.” may provide us with glimpses of “the Real.”

Similarly, physical laws and their mathematical structure may be some sort of “traces” of an underlying structure.

Nonetheless the connection between those traces and that structure “may well be undecipherable.”

This is definitely less than what “structural realism” would expect.

Critic vs Critiqued
D’Espagnat turns from being critiqued to critiquing Bitbol and Zwirn.

He doesn’t see how replacing a static “a priori” with a functional one improves matters.

Either way, how do you explain how Newton’s law of gravity ended up with its precise form?

D’Espagnat says it “partakes very much of utopia” to expect formalism to overcome observation, which is what he thinks Bitbol believes.

An all-encompassing theory of symmetries and so on is unlikely to render it immune to experimental contradiction.

Furthermore, quantum theory’s axioms (a framework theory) may someday be justifiable just on their formal basis.

But those axioms form the basis of quantum theories, and these are theories “in the ordinary sense.”

And it’s those ordinary theories that provide the evidence against locality, for instance.

Because “all men, all civilizations” share the intuition of a reality outside of us, d’Espagnat is willing to give up on Independent Reality only if it’s proved false.

And it’s a conjecture that can’t be proved false.

Maybe some day a conjecture of greater plausibility will supplant the concept of an Independent Reality.

For now, Bitbol’s conjecture doesn’t do that.

Bitbol is reverting to a medieval approach of arguing from the general to the specific, says d’Espagnat.

As for Zwirn, d’Espagnat heartily approves of his analysis of modern science’s conceptual challenges.

D’Espagnat believes Zwirn commits some minor errors in summarizing d’Espagnat’s approach.

It’s not based on “structural realism,” which Zwirn seems to imply.

However, these aren’t a big deal, and the two thinkers agree on much, says d’Espagnat.

In fact, he says Zwirn may have come up with an even more detailed version of “Veiled Reality” than he has.

It’s Not All in Your Head

11 November 2012

Not Just in Your Head

Veiled Threads
Another chapter down, three more to go in Bernard d’Espagnat’s On Physics and Philosophy.

Chapter sixteen, “Mind and Things,” is (relatively) straightforward.

Having spent much of the book undermining physical realism and its kin, he focuses next on the excesses of empiricism and idealism.

Much less combative in this chapter, d’Espagnat seems sympathetic to many of the approaches he describes.

Sympathetic, yes. In total agreement, no.

Ultimately, he’s laying the groundwork for exploring his “Veiled Reality” in some detail as the book draws to a close in the chapters to follow.

Empiricism vs Metaphysics
Empiricism’s guiding principle: all of our knowledge comes from our senses.

It started by discarding metaphysical sources of knowledge.

It then emphasized the role of “elementary sensations.”

Experience vs Reality
Early empiricists seem to have believed primary qualities were real aspects of real objects.

Even if our knowledge can’t exceed our experiences, if properly used our experiences produce a good picture of reality.

A large number of modern-day scientists hold this view, which is a kind of “physical realism.”

Empiricism vs Knowledge
Initially the Vienna Circle epistemologists more energetically attacked Kantian views than scientific realism.

Nowadays, though, logical positivism is understood in an antirealist sense.

But this creates a problem. If the empirical connection between experience and reality is questioned, then are we back to Kant or the neo-Kantians?

D’Espagnat thinks that this quandary sank the logical positivist agenda, but contemporary physics can still learn from some of their ideas.

Knowledge vs Phenomena
“Phenomenalism” has various definitions.

One version states that “knowledge is strictly limited to the (physical and mental) phenomena,” says d’Espagnat.

Phenomena are just the objects of our (unanalyzed) perceptions or introspection.

So phenomenalism is at best consistent with “open realism.”

This is the “weak” version of realism that d’Espagnat favours.

Phenomenalists vs Physical Objects
Unfortunately phenomenalists are often vague about the reality of physical objects.

The Vienna Circle positivists were suspicious of counterfactuals: “If you put this lump of sugar in water then it would dissolve.”

It’s hard to assign properties such as “soluble” to an object without using counterfactuals.

Phenomenalists vs Paths of Knowledge
Another problem was pointed out by Bertrand Russell.

Unless a solipsist, a phenomenalist accepts the existence of other observers and their assertions.

But then why not accept the existence of sound waves, since they convey messages?

But then you’re getting into back into physical realism.

Private Sensations vs Public Science
It’s hard to get around this problem since we have no direct access to other people’s sensations.

They’re private.

But science relies on communicating knowledge.

That’s public.

Object vs Method
A third problem:

We describe objects by describing how to get sense data about them.

But then as objects get smaller and smaller the description gets longer and longer.

How do you describe an electron as a “construct”?

You could describe a cloud chamber, how it has to be prepared, and then the probability that the set-up will produce the hoped-for observation.

Stability vs Instability
But that gets at a problem when you move from phenomenalism to contemporary physics.

To a phenomenalist, an object of knowledge is a stable pattern of perception.

In quantum physics there are probabilities of state vectors not some “inherent stability” of perception.

Classical Instruments vs Quantum Systems
To address Russell’s problem we can assume a measuring instrument is classical.

That way various observers can agree on a measurement.

Furthermore, our observations agree with the rules of quantum physics, so our sensations aren’t entirely private.

It’s a kind of “mutual agreement” between our perceptions and quantum rules.

However, d’Espagnat notes this solution is a “hybrid” one.

And, he notes, in chapter eight he looked at the problems with saying an experimental apparatus is classical.

Operationalism vs Phenomenalism
D’Espagant likes operationalism, a modified version of phenomenalism.

It deals with how to make observations, and quantum rules for predicting observations are unquestionably accurate.

Conventional vs Radical Operationalism
There’s a conventional version of operationalism that’s “moderate.”

It talks as if there are real properties that are measured.

But as seen in chapter seven this leads to ambiguity.

“Radical” operationalism is more content to just describe measurements.

However, that’s hard to do without specifying the objects being measured.

Intrinsic vs Convenient Elements
“Radical” operationalism may consider some perceived forms to be “elements” of empirical reality connected by empirical laws.

But unlike traditional operationalism, it doesn’t consider these forms to have intrinsic significance.

Perceived forms aren’t the “constitutive” bricks of anything.

The radical operationalist is prepared to discard one set of predictive rules for another if they work better.

And if two sets of rules produce the same predictions then we should accept both.

Deductive vs Inductive Logic
However, radical operationalism relies heavily on induction.

If a rule worked in the past then it must work in the future.

That’s not strictly logical.

Rules vs Explanations
Another problem is that people have trouble seeing these rules as a “genuine explanation.”

So do we need the notion of “cause” beyond the realm of just phenomena?

Phenomenal vs Transcendental Causation
Kantians say that causality is inherent in our a priori understanding, not in the objects themselves.

Abner Shimony notes there are many kinds of causality.

He feels this diversity undermines the universal application of this Kantian claim.

Also, cognitive science has blurred the distinction between the phenomenal and transcendental selves.

Therefore categories of understanding can hardly be limited to just the phenomenal self.

Phenomena vs the Mind
Furthermore, in the past century or two, mathematics and physics have undermined the believe that our understanding of phenomena reflected the ordering principles of the mind.

Therefore Shimony doesn’t believe that only phenomena can be the “causes” of other phenomena.

Shimony’s Causation vs d’Espagnat’s Laws
D’Espagnat focuses on predictive laws in constructing his concept of a “Veiled Reality.”

Shimony puts causality at the root of his ontology.

True, the reliability of predictive laws must have some kind of “cause.”

But d’Espagnat still says he and Shimony have very different views.

Transcendental Uniqueness vs Structure
A basically Kantian approach says a “transcendental object” is the “purely intelligible cause” of various phenomena.

Kant believes that objects exist “per se”—but only in experience.

However, he felt there must be a “cause” of these representations.

The cause will be totally unknown to us, but he still gave it a name: the “transcendental object.”

This unknowable cause is singular.

The phenomena it produces are plural.

Therefore the “transcendental object” is unique.

D’Espagnat already acknowledged (in chapter ten) similarities between Kant’s transcendental object and his own views of extended causality and “ground Reality.”

However, d’Espagnat is willing to accept “some sorts of structures” that end up “implying” our scientific laws.

That structure and that connection to our laws will still be “undecipherable.”

Individual Mind vs Mind in General
Operationalism avoids making ontological statements.

However, someone has to set up and run the experiment, and someone has to be observe the results.

So presumably either an individual “mind” or a “mind in general” exists.

Objective Laws vs Mentalist Consciousness
Jean Petitot says we can be “objective” about the laws of phenomena even if we can’t see what’s behind the phenomena.

Galilean space and time are “mental” concepts.

But these mental forms let us construct the legal rules of phenomena, which become “desubjectivized.”

So “mentalist” or “cognitive” is what’s unique to each person’s consciousness.

Things lying in space are therefore neither ontological nor mentalist.

Objectivity vs Ontology
Petitot says that space and time are the crucial notions in classical physics.

In quantum physics the crucial notion would be probability amplitudes.

But space and time seem independent of us, while probability amplitudes are very much connected to an observer.

D’Espagnat says it’s not a crucial distinction as Petitot separates objectivity from ontology.

Petitot’s approach is what d’Espagnat calls a “weak objectivity” or “intersubjectivity.”

Different observers will get the same measurements under the same conditions.

Assumptions vs Justifications
But d’Espagnat tackles Petitot’s approach on two fronts.

The first objection is that stating a rule and justifying a rule are two different things.

Stating that “reality-per-se” is unobservable creates some interesting consequences.

But the statement is basically an axiom.

Galilean physics can still be explained by the “reality of the accidents.”

The big challenge to realism was quantum physics, not Petitot’s or anyone else’s transcendental claims.

Transcendental vs Individual Subject
The second objection is that transcendentalists create a contradiction when they limit “mentalist” and “cognitive” to individual minds.

Petitot and Kant both believe a transcendental subject is impersonal.

It supposedly conveys a priori sensibility and categories of understanding not limited to an individual.

Kant said his transcendentalism differed from Berkeley’s idealism.

However, Kant’s “empirical realism” is still only empirical.

Objects of experience exist in experience.

But experience requires one or more subjects to have that experience.

D’Espagnat says a “transcendental subject” can’t eliminate the role of knowledge in our experiences.

And knowledge depends on cognition.

That knowledge is then communicated intersubjectively, taking it out of the “private realm.”

Plato vs Galileo
Galileo stressed the mathematical structure of natural laws.

Some people take this as evidence he was a “Platonist.”

Alexandre Koyré said Galilean science started from this belief:

Reason and geometry are enough to acquire “intelligence of the real.”

But Galileo took considerable pains to investigate phenomena.

For him to be a Platonist you’d have to equate what’s “empirically real” with a kind of Platonic idealism.

However, Plato’s cave suggests our pursuit of phenomena will get us only as close as some shadow of the “Real.”

Senses vs Innate Knowledge
Also ambiguous is the notion of what is “innate.”

Both Descartes and Saint Augustine believed we could gain knowledge without use of the senses.

But empiricists believe “reality-per-se” is inaccessible.

So how could we ever experience an independent reality?

Empiricism vs Innatism
If we consider Kantian space, time, and causality then these notions must be innate.

Furthermore, Kant’s categories of understanding are a priori, so they too are “innate.”

But in our “semi-intuitive” world-view we follow sensory evidence as closely as possible, yet interpretation still guides us.

Quantum Mechanics vs Innatism
Quantum mechanics is “weakly objective” hence “antirealist.”

Its view of knowledge is somewhat Kantian, but with a strong dose of operationalism added.

This operationalism prevents quantum mechanics from getting too close to Descartes’ innatism.

Furthermore, the simplicity of quantum rules leads us to infer (unprovably yet irrefutably) a simplicity in the “Real.”

D’Espagnat says this approaches Nicolas Malebranche’s “vision in God.”

Empiricism vs Conventionalism
D’Espagnat says reading between the lines one can see evidence of Henri Poincaré’s “ontological” stance.

Kant believed the axioms of geometry were a priori.

The discovery of non-Euclidean geometries refuted such an idea.

Poincaré saw the axioms as neither a priori nor as experimental data.

They are conventions, he decided.

“One geometry cannot be truer than another one, it can only be more convenient,” he wrote.

The Convenient vs the Real
Poincaré felt the same way about physics.

Experimental data and theories about them are not descriptions of an independent reality.

They are convenient and concise “pictures” to describe observations and connect them.

So, for instance, the ether hypothesis is “convenient.”

Whether or not ether exists is the concern of the metaphysician, not him.

Supporters of “objectivist realism” complain conventionalism favours convenience over truth.

However, both Poincaré and d’Espagnat reply that if rules make the right predictions then we might as well call them “true.”

Knowable vs Underlying Reality
Poincaré says relationships between things are “objective” when they’re “the same for everybody.”

Poincaré says that the relationships between things is “the sole objective reality.”

These relationships cannot be conceived independent of a mind that conceives them.

However, “they are objective nevertheless since they are shared by all thinking beings.”

Poincaré is definitely referring to real, though hidden, objects.

And Poincaré says we can discover true relationships between these real objects.

D’Espagnat says that the only way to make sense of these statements is to believe Poincaré believed some reality that underlies phenomena.

Otherwise it’s hard to imagine how there could be real relationships between real, if hidden, objects.

Separability vs Non-separability
Although d’Espagnat’s viewpoint and Poincaré’s implicit ontology are similar, they differ over “separability.”

Poincaré’s “structural realism” involves “objects-per-se”—unknowable but plural.

D’Espagnat says modern physics does not support separability, and hence there must be “some underlying coherence, or deep unity” to this hidden reality.

Rules vs Ontology
Poincaré believed the equations of classical physics served two purposes.

First, they describe the structure of various laws.

Secondly, they describe the value of certain properties at different points.

Poincaré was happy with the first role.

He had doubts about the second role as he felt equations indicated only what would be observed at those points, not what was pre-existing there.

D’Espagnat wonders if we can give up the second role of an equation’s symbols while retaining the first.

Maybe we could then call this a “structural” realism.

Old vs New Theories
D’Espagnat does note that Poincaré explored ontological issues only with reluctance.

Therefore it would be wrong to attribute this interpretation to Poincaré.

Also, this interpretation has some problems.

As theories evolve, old equations may be seen as merely approximate.

Also, a new theory may have little in common with the old theory.

This would imply the structure of “Reality” is very different under this new theory.

However, normally one could derive the old theory’s equations from the new theory’s equations.

In that case there still might be a meaningful, permanent substratum to reality, despite the objection of radical idealists.

Structural Realism vs Veiled Reality
In the end, d’Espagnat says, structural realism can be justified only after it’s watered down so much it looks like his own “Veiled Reality.”

In the final chapters d’Espagnat says he’ll have to steer between the conceptual difficulties of classical phenomenalism and how physical realism is contradicted by its own science’s results.

Background image: NASA, ESA, J. Richard (CRAL) and J.-P. Kneib (LAM) via


The Portable Rainbow

7 July 2012


Under the Veil
Chapter 15 (“Explanation and Phenomena”) of Bernard d’Espagnat’s On Physics and Philosophy continues the previous chapter’s exploration of causation and explanation.

With quantum mechanics relying on observation and denying a naive realism, is an empirical explanation good enough?

For d’Espagnat there’s a need to postulate a “Veiled Reality” of which we may only be able to sneak some peeks, if at all.

Nonetheless he believes it’s there.

Prediction vs Explanation
If you measure the state of quantum particles and find a correlation-at-a-distance how do you explain it?

Quantum mechanics is a “recipe” to predict observations from initial conditions. It’s an “explanation” on the level of empirical reality.

If you need some “deeper” explanation about what’s “really” going on you might add “hidden variables” to extend the standard theory.

But then you run into problems with Bell’s Theorem and the experimental results of Aspect and others.

If you don’t have knowledge of a deeper reality, how can an empiricist justify using induction to create laws?

Just because a law summarizes certain observations on certain days, why should we think it’s universal?

Induction vs Unknowable Explanation
For d’Espagnat, a belief in the existence of a deeper reality is enough to ground our use of induction.

We may be incapable of comprehending this deeper reality, but our belief that there is one suggests a connection between empirical reality and an underlying reality.

That belief is enough for d’Espagnat to accept induction without having to justify it every time it’s used.

Even if we don’t know anything much about this deeper reality, there’s still no “logical inconsistency,” d’Espagnat says, in using its presumed existence to justify induction.

Furthermore, this deeper reality—whether “veiled” or even entirely unknowable—will not be an arbitrary reality, d’Espagnat says.

Rainbows vs Quantum Concepts
Although rainbows can’t be directly grasped and manipulated, they’re explained in classical physics.

A description of rainbows might illuminate how we speak about quantum systems.

A rainbow (including its two “bases”) will look different from different locations.

Hence, the particular rainbow someone sees is observer-dependent.

The same reliance on location is true if you set up automatic cameras.

Hence you can’t say that just because we’ve taken a picture of a rainbow that this rainbow “really” existed before that observation.

Similarly, out tendency to “reify” (seeing something as concrete and real) means we jump from an observation to assuming what was observed somehow pre-existed.

If we can argue that a rainbow doesn’t pre-exist, we should be able to argue that a quantum object doesn’t pre-exist either.

Dinosaurs vs Humans
However, surely dinosaurs existed before humans ever walked the earth. No observation was required to bring them into existence.

D’Espagnat says that dinosaur bones are like the pointers of an experimental set-up. We see something and conclude it’s real.

Though d’Espagnat says it’s real, he specifies it’s real in the realm of “empirical reality.”

However, this empirical reality is hardly an arbitrary production. Its qualities are severely constrained, and in the end observers tend to see mostly the same thing.

Explanations vs The Final Key
Classical physics can still provide us with “explanations” as long as we don’t presume they derive from a deeper reality.

D’Espagnat adds that we should not conclude that these explanations are the “final, ultimate key” to understanding the world.

D’Espagnat vs Other Views
I’ve concentrated above on d’Espagnat’s ultimate positions, but here are some examples of how he explains his disagreement with other people’s positions (real or conjectured).

D’Espagnat vs Cassirer
If you see correlations in a quantum experiment then d’Espagnat has trouble imagining Cassirer’s “logical necessity” could explain each particular observation in a sequence.

True, Cassirer could choose (or could have chosen, as he’s now dead) hidden variables, but d’Espagnat says that’s too “metaphysical” for Cassirer, and the Aspect-type experiments have refuted them anyway.

Maybe Cassirer equates “logical necessity” with a pre-existing logos, a primary notion of absolute existence.

D’Espagnat says that whole idea is something the neo-Kantians were trying to get away from, so again it doesn’t sound like Cassirer.

Nonetheless, d’Espagnat says his own position is consistent with considering the “Real” (with a capital R) to consist of such a logos.

D’Espagnat vs Carnap
Carnap says scientists should be more modest. They shouldn’t try to explain the “why” but just the “how” of phenomena.

Carnap’s position is that simply producing entities, such as Driesch’s “entelechy” as an explanation for tissue regeneration, is irrelevant as there are no “laws” connecting conditions and observations.

So what about d’Espagnat’s “Real”? Is it just a meaningless entity?

It doesn’t help us predict anything, so maybe it’s not an explanation at all.

D’Espagnat responds by saying scientists long ago were implicitly believing in the realism of a world ruled by classical physics even if explicitly they concerned themselves with just the laws of observation.

Even some realists nowadays, says d’Espagnat, acknowledge that there could be an underlying reality, not attainable through “discursive knowledge,” that nonetheless grounds our empirical reality.

Furthermore, if laws relate just to our known observations, then what happened before we made those observations?

Carnap, according to d’Espagnat, said laws could exist before such observations but the truth of the laws could not be judged.

D’Espagnat says this amounts to Carnap’s acknowledging a “human-independent reality” that has a structure we might never know.

Since quantum mechanics only predicts observations and does not “explain” underlying reasons, this implies to d’Espagnat that a “Veiled Reality” has a meaning even if we can’t explore it empirically.

But what if we imagine Carnap meant some kind of “linguistic framework” involving “nature” and “existence” that replaced the usual meaning of those terms?

In a world ruled by classical physics it makes sense to speak of “things” and their qualities makes sense.

In a world ruled by quantum physics it makes sense to speak of “sense-data” rather than “things.”

D’Espagnat says this approach works fine for making sure scientific statements are clear.

But it’s not satisfactory from the philosophical point of view.

Carnap, d’Espagnat says, is just “masking” not “eliminating” the connection we make between an explanation of observations and an explanation of what’s going on in some underlying reality.

Since a linguistic framework is “chosen by us” according to Carnap it sounds a bit arbitrary and not like a genuine explanation.

An Influential Relationship

1 July 2012

Influential Arrows

Just Causes and Side Effects
Chapter 14 (“Causality and Observational Predictability”) of Bernard d’Espagnat’s On Physics and Philosophy examines how, and if, we can use the concepts of causation and influence to explain the world.

Reality vs Observations
Taking a break from examining the “notion of reality” d’Espagnat uses this chapter to argue it’s better to predict observations than predict “things as they are.”

Animism vs Empiricism
Aristotle saw causation as related to human will, and even inanimate objects seemed to have some animistic will—as seen when a falling stone somehow desires to return to its natural resting place.

Empiricists went to the other extreme. Physical laws should just be descriptions of events and their regularities. However, what initial conditions are the “cause”? You end up with too many empirical laws.

Mathematical vs Physical Determinism
If two very close points rapidly diverge then they’re not likely to be “physically deterministic.” It’s too hard to calculate their exact paths.

“Strong objectivists” argue that science accumulates knowledge about an underlying reality, not just our experimental observations.

Some strong objectivists argue that “chaotic” behaviour is an example of indeterminism, and others argue initial conditions have to be repeated exactly for us to say deterministic laws apply.

The first approach implies imperfect observations or calculations show reality is indeterministic, but that’s strange since strong objectivists believe in an underlying reality separate from our fuzzy data.

The second approach is a problem since a strong objectivist can’t be absolutely sure the initial conditions won’t be repeated.

Laws vs Predictions
D’Espagnat also criticizes the claim we’ve seen the “end of certainties” just because some calculations make predictions impossible.

He says that’s too harsh as we can still believe in our laws even if sometimes in practice we can make reliable predictions only for the near future.

Classical vs Quantum Indeterminacy
D’Espagnat cautions against regarding chaos theory as some overriding conceptual triumph as it’s grounded on classical concepts of space and time.

Classical physics falters where quantum physics and its apparent indeterminacy excel, particularly on the microscopic level.

Yet d’Espagnat says the defining feature of quantum mechanics is not its indeterminacy but its “weak objectivity.” The theory confines itself to observations of reality, not claims about reality itself.

Individual vs Statistical Determinacy
D’Espagnat agrees with Kant that “regularity in time”—in which one kind of event is followed consistently by another—is a good way to distinguish the empirically real from, say, the events of a dream.

Kant’s “sin of omission” (understandable because of his time and place) was not to consider statistical regularities in which ensemble probabilities are deterministic.

D’Espagnat emphasizes that quantum mechanics makes reliable predictions for observing ensembles of quantum systems, but these are not probabilities of ignorance about individual systems.

At first glance quantum mechanics may seem indeterministic, but if you keep in mind quantum predictions are about observations of multiple systems then it too is deterministic—if only “statistically.”

Laws vs Facts
D’Espagnat warns against “a variant of nihilism” if you don’t pay enough attention to the difference between laws and facts.

He says even Dirac’s musings that universal constants (such as the speed of light) might change over time don’t threaten that distinction.

The nihilistic danger, d’Espagnat says, comes from sociologists, epistemologists, or “pure philosophers” who see in the history of a changing universe a fundamental lack of stability.

They fail to distinguish between laws and facts, or they fail to appreciate the significance of the distinction.

Causes vs Influences
D’Espagnat imagines a Laplace daemon that can possess total knowledge of events in part of the universe.

The fixed speed of light means, in an Einsteinian world, the daemon need only check events in a point’s past light-cone to predict that point’s future.

However, Bell’s Theorem combined with the experiments of Alain Aspect (and others) proved that the locality hypothesis is false.

Add to that the order (in time) of events can vary by reference frame, and we see that (earlier) cause and (later) effect can be ambiguous.

D’Espagnat thus suggests that faster-than-light influences—or “influential relationships”—do exist.