Wednesday 7 October 2020

Things Themselves are Numbers: Contemporary Pythagoreanism


 

In a simple sense, mathematics may be viewed as an extremely useful tool. The English cosmologist, theoretical physicist and mathematician John D. Barrow, however, holds a slightly different view. That is, he posits the view known as Pythagoreanism, summing up the relationship between mathematics and physics in the following way:

“By translating the actual into the numerical we have found the secret to the structure and workings of the Universe.”

So the Universe and its parts are assigned numbers… Or are described by numbers… Or are captured by numbers… Or are explained by numbers… Or are (to use Barrow’s own words) translated into numbers.

But what does all that actually mean?

Sure, if Pythagoreanism holds at least some water, then it’s no wonder that so many people have also believed that through maths (as Barrow puts it) “we have found the secret to the structure and workings of the Universe”. But even here there’s a non-Pythagorean (as it were) remainder. After all, maths finds the secret of things which already exist — i.e., the “structure and workings” of the world. It isn’t actually being argued that these structures and workings are literally maths. The world is not itself maths.

… Or is it?

To the Pythagorean, the world and its parts are actually mathematical. This means that it isn’t that maths is simply helpful for describing the world — the world itself is mathematical. Indeed one must take this literallyHere’s Barrow again on the Pythagorean position:

“[The Pythagoreans] maintained ‘that things themselves are numbers’ and these numbers were the most basic constituents of reality.”

And Barrow then becomes ever clearer when he continues in the following manner:

“What is peculiar about this view is that it regards numbers as being an immanent property of things; that is, number are ‘in’ things and cannot be separated or distinguished from them in any way.”

Moreover:

“It is not that objects merely posses certain properties which can be described by mathematical formulae. Everything, from the Universe as a whole, to each and every one of its parts, was number through and through.”

It’s hard to grasp what the phrase “things themselves are numbers” even means. Can we say that reality and its parts are mathematics (as in the “is of identity”)? That reality and its parts are literally made up of numbers or equations? That reality and its parts somehow instantiate maths, numbers or equations?

And what does it mean to say that “numbers are in things”? Indeed there’s a problem here. If things are literally numbers, then how can numbers also be “in” things? In other words, how can numbers be in themselves? That would be like saying that cats “are in” cats; or that a dog is in the very same dog.

The Unreasonable Effectiveness of Mathematics

The important distinction here is that this isn’t about the “unreasonable effectiveness of mathematics in the natural sciences”. (In which we note the miraculous fact that maths is often a perfect tool for describing the world and then wonder why that is the case.) This is about (to use Barrow’s words again) “the Universe as a whole, [and]each and every one of its parts [being] number through and through”.

Thus description and being are two very different things.

Another way to describe the maths-world relation is to say that (as Barrow again does) that

“mathematics has proved itself a reliable guide to the world in which we live and of which we are a part”.

Yet here again, saying that mathematics is “ reliable guide to the world” is no more of a Pythagorean statement than saying that maths describes the world.

To be clear. A map of Essex is not actually Essex. The set of rules for chess is not an actual game of chess. (Though each game of chess is always — as it were — a variation on the rules of chess.) So it may well be the case that if we didn’t have a map of Essex, then we’d get lost in that county. Similarly, if we didn’t have maths, then we wouldn’t have a reliable guide to the world.

But what of that “miracle” that is math and its relation to the world?

The Hungarian-American theoretical physicist Eugene Wigner (famously) put it this way:

“The miracle of the appropriateness of the language of mathematics for the formulation of the laws of physics is a wonderful gift which we neither understand nor deserve. It is difficult to avoid the impression that a miracle confronts us here, quite comparable… to the two miracles of laws of nature and of the human mind’s capacity to divine them. The enormous usefulness of mathematics in the natural sciences is something bordering on the mysterious and… there is no rational explanation for it.”

Albert Einstein was similarly perturbed when he wrote:

“How can it be that mathematics, being after all a product of human thought which is independent of experience, is so admirably appropriate to the objects of reality?”

However, Einstein’s own conclusion appears to be radically at odds with Wigner’s when he continues with the following words:

“In my opinion the answer to this question is, briefly, this: As far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality.”

Despite those sceptical remarks from Einstein, let’s get back to the being I mentioned a while back.

The physicist and cosmologist Max Tegmark puts the contemporary case for (Pythagorean) being in the following very concrete example:

“[If] [t]his electricity-field strength here in physical space corresponds to this number in the mathematical structure for example, then our external physical reality meets the definition of being a mathematical structure — indeed, that same mathematical structure.”

To spell out the above.

Max Tegmark isn’t saying that maths is perfect for describing the “electricity-field strength” in a particular “physical space”. He’s saying that the electricity-field strength is a “mathematical structure”. That is, the maths we use to describe the electricity field is one and the same thing as the electricity field. Thus, if that’s the case, the “miracle of mathematics” is hardly a surprise! That’s because it’s essentially a situation in which that maths is describing maths. And if maths is describing maths, then the word “describing” is surely not apt word to use in the first place.

In any case, Tegmark gives us more detail on his position when he tells us that

“there’s a bunch of numbers at each point in spacetime is quite deep, and I think it’s telling us something not merely about our description of reality, but about reality itself”.

Yet Tegmark appears to contradict himself in the above. At one point he says that a field “is just [ ] something represented by numbers at each point in spacetime”. So here we have the two words “something represented”. Yet elsewhere Tegmark says that the field “is just” (or just is) a mathematical structure — the latter two words implying that all we have is number. To repeat: Tegmark says that the field is “represented” by “three numbers at each point in spacetime”. Yet he doesn’t (in this passage at least) say that the field is a set of numbers (or even a “structure” which includes numbers).

So perhaps there’s a difference between saying that “things themselves are numbers” (as the Pythagoreans did) and saying that the world is mathematical. (I may be drowning in a sea of grammar here.) The latter may simply state that the world exhibits features which are best expressed (or described) by mathematics. The former, on the other hand, says that the world literally is mathematics. But (as already stated) it’s hard to grasp what that even means.

Monday 5 October 2020

Do you realise just how tiny strings are?


A Short

It’s hard to grasp just how small the strings of string theory are.

Strings are to contemporary physicists just as atoms were to the physicists of the 19th century or particles were to the physicists of the 20th century. In fact strings are said to be fantastically smaller than protons and neutrons. (See the complicating note at the end of this piece.)

… Or are strings really in the same boat as particles and atoms once were?

The American theoretical physicist and string theorist Brian Greene puts the problem in this way:

“Strings are so small that a direct observation would be tantamount to reading the text on this page from a distance of 100 light-years: it would require resolving power nearly a billion billion times finer than our current technology allows.”

It’s not surprising, then, that

“[s]ome scientists argue vociferously that a theory so removed from direct empirical testing lies in the realm of philosophy or theology, but not physics”.

So how can we make both philosophical and everyday sense of string theory’s strings?

As stated, the situation physicists find ourselves today can be compared to the situation physicists found themselves in the 19th century with atoms and with particles in the 20th century… Except that although atoms and particles were never directly observed at those times, they were, nonetheless, indirectly “observed”. More importantly, both atoms and particles did have results when it came to (to use Brian Greene’s word) “direct empirical testing”. That is, there were testable and observable happenings which (as it were) hinted at the existence of both atoms and particles.

Yet we simply don’t have that with strings.

Perhaps strings are, therefore, a mathematical contrivance. I say that because many string theorists (more or less) state the same thing. Take the words of the American theoretical physicist Michio Kaku. He wrote:

“My own view is that verification of string theory might come entirely from pure mathematics, rather than from experiment.”

Saying that string theory is hyper-mathematical isn’t to say that strings don’t explain anything. They certainly do. They both explain and unify a hell of a lot of things. However, none of that explanation or unification has anything to do with direct empirical testing.

Thus it is highly unlikely that a string — even in the (near?) future — will ever be observed. But what about the empirical testing of strings in the future? It’s hard to work out what exactly that could mean. How can something so fantastically small ever have an effect in — or on — an experiment?

Despite saying all that, Brian Greene himself has faith and hope.

Greene finds the views of sceptical scientists “shortsighted” or “at the very least, premature”. Yet Greene also acknowledges that “we may never have technology capable of seeing strings directly”. However, he nonetheless concludes that “the history of science is replete with theories that were tested experimentally through indirect means”. But which “indirect means” has Greene in mind for strings? He doesn’t say. (At least not directly after these statements.) It’s hard to imagine that something which would “require resolving power nearly a billion billion times finer than our current technology allows” could even provide indirect evidence. And that may be because (as already hinted at) a string is entirely the child of mathematical theorising. That is, a string is most certainly not the child of physical experiments — or even of any theorising based on physical phenomena.

Note:

One point that is never made entirely clear (at least not in popular science books!) is this: if what we take to be a particle is the instantiation of various levels — or types — of energy vibration of a string, then clearly strings can’t be either smaller or larger than a particle. (In the opening image, a quark is deemed to measure 10−16 cm; whereas a string comes in at 10–33 cm.) That’s because a particle actually is a vibrating string. Yet we have indirect physical evidence of particles, but no indirect physical evidence of strings at all.

 

Saturday 3 October 2020

Daniel Dennett vs. Roger Penrose: Strong AI


 A Short

A while back, the philosopher Daniel Dennett made it seem as if the mathematical physicist Roger Penrose took an immediate and emotional position against strong artificial intelligence (sAI). Indeed Dennett quotes Penrose as saying: “Somehow I’ve got to prove that this is wrong.” In other words, Penrose had non-scientific reasons for rejecting sAI… But is that actually a quote from — or even a paraphrase of — Penrose? I say that because Dennett uses the phrase “he thought” rather than “he said”. This may well be a simple slip of grammar on Dennett’s part. Though if not, then Dennett was simply guessing as to what Penrose thought. After all, Dennett can’t have known what Penrose thought unless he told him.

In any case, the main position that Dennett upholds is that strong AI is actually entirely in tune with both physics and biology; whereas Penrose’s position seems to be at odds with these disciplines. In Dennett’s own words:

“[W]hat [Penrose] has seen… is that the only way you’re going to show that the idea of strong artificial intelligence is wrong is by overthrowing all of physics and most of biology!”

This seems to make intuitive sense. That is, it seems that nothing in sAI clashes with either physics or biology. What Penrose argues, on the other hand, does clash with both. But there’s a problem here for Dennett. Physics (as physics) has nothing to say about intelligence, let alone about consciousness or even life. Thus when AI theorists talk about intelligenceconsciousness and life, they’re essentially going beyond physics. So in that sense, strong AI isn’t really in tune with physics at all. Of course it can now be said that nothing in sAI actually and clearly contradicts anything in physics. That may be true; though it is hard to decipher how any talk (by AI theorists) of intelligence, consciousness or life could contradict anything in physics.

What about sAI squaring with biology or natural selection?

Dennett is on safer ground here in the simple sense that some evolutionary theorists do indeed talk about intelligence and life. And some even talk about consciousness. (Other evolutionary theorists have “no need for the hypothesis of consciousness”.)

In any case, Dennett is correct to argue that a “revolution in physics” is required in order to sustain Penrose’s scepticism about sAI. He’s correct primarily because Penrose has himself often talked about the need for such a revolution. Primarily, that revolution is required to square relativity theory and quantum mechanics (see here). However, this revolution also ties in with the revolution that’s required to get to grips with the nature of consciousness — in which both quantum mechanics and gravity, according to Penrose, must play a role at the level of the brain's microtubules (see here).





Thursday 1 October 2020

Jaegwon Kim’s Epiphenomenalism?





 A Short

How do we solve the problem of epiphenomenalism? (This is a position summed up well in this way: “Subjective mental events are completely dependent for their existence on corresponding physical and biochemical events within the human body yet themselves have no causal efficacy on physical events”.)

Here’s one possible way offered by the Korean-American philosopher Jaegwon Kim.

Kim argues that “we should not think of the relation of neural events to their supervening mental events as causal”. Moreover,

“supervening mental events have no causal status apart from their supervenience on neurophysiological events that have ‘a more direct causal role’”.

This means that this isn’t a case of a mental event at time t causing a neurophysiological event at time t 1. No: if a mental event (M) supervenes on a neurophysiological event (N), then both the mental event and the neurophysiological event occur at one and the same time. So we can’t say that mental event M causes neural event N if they occur at one and the same time.

This is like the H₂0-water case.

That is, we don’t first have a set of H₂0 molecules which cause water. When we have a set of H₂0 molecules, we also have water. H₂0 molecules, then, don’t bring about (or cause) water. H₂0 molecules constitute (or are identical to) water.

On Jaegwon Kim’s account, we both can and cannot say that mental events are epiphenomenal. We can say that they’re epiphenomenal in that if mental event M occurs at one and the same time as N, then it can’t be epiphenomenal. More accurately, if M “inherits the causal power” of N (or if it “rides piggy back” on N), then it both has causal power and is not epiphenomenal. On the other hand, if M is indeed riding pigging back on N, then we can see it as being epiphenomenal. But, again, if M and N occur at one and the same time and are intimately connected, and if M also inherits the causal power of N, then in what sense is M truly epiphenomenal? (Perhaps this is simply a matter of taste or grammar.)

But if we tie M and N so closely together, aren’t we also saying (or implying) that M literally is N (as already hinted at with the H₂0-water example)? That is, that M and N are identical? Again, as with the epiphenomenal nature of M, both yes and no. From the outside, all we have is N and human behaviour. However, ontologically (or from the inside), M is clearly not identical to N. Again, from the first-person (or subjective) point of view, M is not a physical event. From the third-person point of view, on the other hand, M doesn’t factor at all except in terms of behaviour and “verbal reports”. M alone is also (according to the American philosopher Donald Davidson) incapable of falling under any natural laws.

References

Kim, Jaegwon, ‘Multiple realization and the metaphysics of reduction’ (1992).
 — ‘Mental Causation’ (chapter 6) in his Philosophy of Mind (1996).

Friday 18 September 2020

Merely Verbal Ado About Nothing: David Chalmers, Facts, Consciousness


 

Contents: i) Introduction ii) The Facts and What We Say About Them iii) Stipulation Examples: iv) A Random Cup v) Is a Virus Alive? vi) First-Person Data vii) Eliminative Materialists vs. Reductive Functionalists viii) Causation ix) Bridge Laws x) Conclusion: Facts Matter and Consciousness

The title of this piece is partly based on David Chalmers’ paper ‘Verbal Disputes’. However, I relied far more on Chalmers’ book The Consciousness Mind: In Search of a Fundamental Theory than I did on his ‘Verbal Disputes’. (This paper is very long — 48 pages — and it covers many subjects.) Chalmers also gave a seminar on this subject; which can be found on YouTube here (see image above).

Many philosophers have tackled the “problem” of whether certain philosophical issues are “merely verbal disputes” or not. This debate goes back through the centuries. (Perhaps it was best highlighted by the logical positivists in the 1920s and 1930s.) In terms of contemporary philosophy, the notion that some philosophical issues are merely verbal has often been leveled at what is now called “analytic metaphysics”. Chalmers himself tackles some of these issues. (For example, he discusses whether a random booklike x is a book. Or, to use the contemporary jargon, is it only a collection of “particles arranged” bookwise?) However, Chalmers himself never names names and he certainly doesn’t use the term “analytic metaphysics”.

The Facts and What We Say About Them

Philosophy-scientist Smith has access to all the facts, laws, information, etc. about spatiotemporal slice (or state of affairs) A and says that it is x, y and z. Philosopher-scientist Jones has access to all the same facts about the same spatiotemporal slice (or state of affairs) A and says that it is a, b and c. Yet both Smith and Jones agree on the facts. This must mean that what Smith and Jones say about A is over and above the facts. In addition to facts, Smith and Jones needed to bring in theory, conceptual decisions, prior semantics, etc. into the discussion.

The given facts may well be determinate; though it doesn’t follow from this that what we say about them is also determinate. Or, in another manner of speaking, the facts alone don’t entail what we say about them…

But hang on a minute.

One may now wonder how this clean and neat distinction between facts and what we say about them can be upheld. After all, aren’t the facts (or what we take to be the facts) themselves somewhat dependent on what we say? David Chalmers himself doesn’t only argue that what we say is indeterminate. He also argues that “the facts [themselves] are indeterminate”.

Much of what’s just been said is fairly standard in science and in the philosophy of science. That is, the very same facts (or data) may engender different theories. Indeed some philosophers have argued that the very same facts (or data) could engender a (possible) infinite amount of theories. This situation is called the underdetermination of theory by the data and has been widely discussed in analytic philosophy.

And here again we can question the clean and neat separation of empirical data from the theories which, it seems to be supposed, come later.

Stipulation

Now Chalmers often mentions what he calls “stipulation”. The basic point is that if we stipulate what we mean by a particular word, then the answers to the questions about facts, data, what x is, etc. must — at least partly — follow from such stipulations. Of course some people will be horrified by the argument that acts of stipulation are decisive when it comes to what we take to be matters of fact. But it’s not that simple.

There is a problem with over-stressing the importance of stipulation; or even with simply emphasising the importance of stipulation at all. Chalmers sums up this problem with a joke. He writes:

“One might as well define ‘world peace’ as ‘a ham sandwich.’ Achieving world peace becomes much easier, but it is a hollow achievement.”

As it is, Chalmers only applies his joke to a single case: consciousness. So perhaps it can also be applied to other cases (such as the later cases of a random cup/book, virus, etc.). Clearly, even someone who argues that stipulation is important won’t also accept that we can define the words “world peace” as “a ham sandwich”. In turn, some philosophers and laypersons will feel just as strongly about claiming that, say, a “computer virus is alive” or that “bacteria learn”. The philosopher P.M.S. Hacker, for example, holds a very strong position on the philosophers and scientists who use such terms (or words) in ways that are radically at odds with everyday usage (see Hacker’s ‘Languages, Minds and Brain’ in Mindwaves). Many physicists, on the other hand, are very keen on using old words (or terms) in very different ways. (Think here of “information”, “space”, “time”, “intelligence”, “law”, “string”, “hole”, etc.)

Some Examples

A Random Cup and a Random Book

Let’s look at some more examples from David Chalmers. He asks:

“Is a cup-shaped object made of tissues a cup?”

The problem here is that it’s not clear if Chalmers meant toilet tissues or biological tissues in this example. In the former case, then, toilet tissues wouldn’t hold liquid. Thus, surely by definition, any x made out of toilet tissues couldn’t be a cup… Or could it?

What about biological tissues which could hold liquid?

In any case, let’s take it that whatever Chalmers meant by “tissues”, these tissues can indeed hold liquid.

Now take this question:

Is it the case that if any x functions as a cup, then surely it is a cup?

Here’s another question:

What if this cup-shaped (or particles arranged cupwise) object wasn’t designed to be cup?

Does that matter? If it holds liquid, and it even looks like a cup, then surely it is a cup. Why does it matter that it wasn’t designed to be a cup? Is whether it does or doesn’t matter a purely stipulative matter? In other words, is the following the case? -

x can only be classed as a “cup” if it were designed to be a cup.

This would mean that any natural object which were used as a cup could never be classed as a “cup” or even be a cup. Yet all sorts of natural things are used as functional devices which we then name according to their functions (e.g., a stick classed as a “weapon”, extracted venom classed as “poisons”, etc.). Does their natural status stop them from being named as functional devices (such as weapons)?

In any case, whether people call x a “cup” or not, they’re all still talking about the same x. Not only that: in the tissue-cup case, all people agree that it looks like a cup and can be used as a cup. The only difference, then, is what Chalmers calls “terminology”.

Here’s another question from Chalmers:

“Is a booklike entity that coagulated randomly into existence a book?”

This is like the infinite monkey theorem in which, after an infinite amount time in which an infinite amount of monkeys play with a typewriter, at least one of them will produce the complete works of Shakespeare. (In an infinite amount of time, surely an infinite amount of monkeys will produce the entire works of Shakespeare an infinite amount of times.) Such is the nature of the logical possibility which Chalmers is so keen on.

In any case, I presume that Chalmers doesn’t only mean book-shaped or arranged bookwise. Surely something that’s simply shaped like a book can’t be a book. That’s because, after all, it may not have any words in it. Then again, if stipulation rules, then why can’t shape alone be a necessary and sufficient condition for bookhood?

But let’s say that this random book does contain words. Not only that: it contains words which make sense. Here again we can ask the following question:

Is it relevant that this “booklike entity” is natural and wasn’t produced to be a book?

After all, if it looks like a book and contains grammatical sentences, a coherent story, etc., then surely it must be a book.

Is a Virus Alive?

David Chalmers tackles the case of whether or not a virus is alive. He writes:

“On theory might hold that a virus is alive, for instance, whereas another might hold that it is not, so the facts about life are not determined by the physical facts… the facts about life are indeterminate.”

One can’t read off from the facts alone whether or not something is alive. In other words, there’s more to being alive than the facts. To use Chalmers’ term, the facts may well be determinate; though what we say about them isn’t.

Let’s say that everyone agrees that a virus moves. Everyone may agree on its genetic structure. Etc. But it doesn’t follow from all these facts that everyone also agrees that the virus is alive. Some philosophers or scientists may see the virus as being a (biological) machine and therefore neither alive nor dead. (Though why would a virus’s machine-like nature automatically mean that it’s not alive?) To take another extreme interpretation. Some philosophers may even see the virus as being a simulation or simply a projection of our minds.

But what of a computer virus? Chalmers asks:

“Is a computer virus alive?”

This taps into the ancient debate of vitalism. Perhaps those same arguments should also be used to show that computer viruses are either alive or dead. It may be more complicated this time around; though functional, structural and physical criteria will be just as important as they were when vitalism was finally given up.

Indeed there’s a radical aspect to this. If the criteria of aliveness which worked for biological beings can also be applied to computer viruses, and also be acceptably or justifiably applied, then computer viruses must also be alive. After all, the term “computer virus” was coined precisely because such a thing fulfilled most — or even all — the functional, structural and physical criteria for aliveness.

First-Person Data

Chalmers gives an interesting example of the facts not determining what we say about them. It’s interesting because the status of these particular facts can itself be disputed. In addition, the subject area is one that’s rarely given as an example within this particular philosophical context.

Chalmers’ subject is what he calls “first-person data”. That is, what people say (or report) about their own conscious experiences or mental states. The basic point is that “all sorts of theories remain compatible” with such data,

“from solipsistic theories (in which only I am conscious) to panpsychist theories (in which everything is conscious); from biochemicalist theories (in which consciousness arises only from certain biochemical organizations) to computationalist theories (in which consciousness arises from anything with the right sort of computational organization); including along the way such bizarre theories as the theory that people are only conscious in odd-numbered years (right now, it is 1995)”.

The point here is:

“How can we rules out any of these theories, given that we cannot poke inside others’ minds to measure their conscious experience?”

What’s more, “[a]ll such theories are logically compatible with the data, but this is not enough to make them plausible”.

Now this particular example is problematic because it’s hard to see first-person data as being factual in the first place. That is, even if first-persona data consist in “verbal reports” which are indeed scientifically kosher, it’s still the case that the subject matter of those verbal reports may not itself be scientifically kosher. In any case, the facts alone (in this case) don’t necessitate what we say about them (i.e., our theories, concepts, words, statements, etc.).

But, here again, the facts/what we say about facts opposition can of course be questioned.

Still, what about the case when two people agree on the facts and yet say different things about them? That is, they don’t say different things about what the facts are and what their natures are. What they disagree on is what follows from the facts or how the facts are interpreted.

So, in Chalmers’ example, those in disagreement accept that subject S is having a mental state that, say, involves an experience of a red rose. They agree on this because they agree on S’s verbal reports about his own experiences or mental states. Now to get back to what Chalmers has already stated: that this very experience of a red rose can be explained in terms of a solipsistic theory, a panpsychist theory, a “biochemicalist” theory, a computationalist theory and an odd-numbered years theory. In other words, S’s experience of a red rose (not the red rose itself — if the two can be completely distinguished at all) isn’t doubted and even its nature may be agreed upon. The problem comes when that experience is theorised about — or interpreted — in different ways. In other words, there is an experience of a red rose (or, more correctly, the experience of a red rose is verbally reported); and it may even have a specific nature (despite it being first-person). However, how do we explain the experience itself? How do we account for it?

Eliminativist Materialists vs. Reductive Functionalists

Chalmers gives another example when he compares the positions of reductive functionalism and eliminative materialism. Here again the reductive functionalist and eliminative materialist both (more or less) agree on the facts. However, they still disagree on what Chalmers calls “terminology”. In this case, the eliminativist materialist and reductive functionalist (more or less) agree on the fact that “there is discrimination, categorization, accessibility, reportability, and the the like”. They even (more or less) agree on the philosophical and scientific accounts of such things. Therefore the only thing they disagree on (at least according to Chalmers) is that the reductive functionalist believes that “some of these explananda deserve the name ‘experience’”. The eliminativist materialist, on the other hand, believes that “none of them do”.

If discrimination, categorization, accessibility, reportability, etc. literally are — or literally constitute — experience, then surely experience (or simply the word “experience”) can be eliminated (at least in theory). In other words, experience (or the word “experience”) adds nothing to the pot. So this would mean that disagreement in this case truly is merely verbal.

Of course there may still be what’s called “semantic indeterminacy” when it comes to words like “discrimination”, “accessibility”, “reportability” and “categorization”. (Some philosophers have argued that this kind of semantic indeterminacy exists across the board. Others philosophers have also argued that it can’t exist across the board because such a state of affairs would somehow render communication — and even communal action — impossible.)

Causation

Chalmers even uses causation — or at least necessary causal relations — to highlight the point that theories, concepts, etc. are over and above the facts. This is (it can be supposed) Chalmers’ take on what’s called Humean supervenience (which has been much discussed in analytic philosophy).

Firstly, we have the facts about physical “regularities”. But what if “causation is construed as something over and above the presence of a regularity”? Indeed Chalmers goes so far as to say that “it is not clear that we can know that [causation] exists”.

To be clear, this isn’t really about the strong distinctions which can be made between the many things which supervene and their “supervenience bases”. It’s about the actual “failure of logical supervenience”. More explicitly:

“[F]acts about causation fail to supervene logically on matters of particular physical fact.”

Thus anything we say about the causation doesn’t “logical supervene” on the facts alone. So even causation (like our stipulations about what a cup/book is, what is alive, etc.) are over and above the facts. Does this mean that causation-talk too is merely verbal?

All this depends on what Chalmers means by “causation”.

The 18th century philosopher David Hume would have accepted that B always follows A. However, there’s no necessary link between the two that’s somehow over and above what we observe. Thus if there’s no necessary link, then B simply follows A. After all, Chalmers himself distinguishes causation from “mere succession”. But does this Humean picture automatically mean that we don’t actually have causation at all? Is non-observable (or non-empirical) metaphysical necessity necessarily built into all talk of causation?

In any case, this isn’t really the place to discuss Humean supervenience or even causation. The point is, though, that whatever philosophical position we take on “mere succession” (or causal relations) it will be over and above what it is that’s “behind”, “beneath” or “between” the successions (or relations) we talk about. Basically, what we say about physical (or causal) relations is (or can be) over and above the facts.

Bridge Laws

Philosophers (specifically in the philosophy of mind) often use the technical term bridge laws. Bridge laws are said to tie lower-level phenomena to higher-level phenomena. In the case of the philosophy of mind, facts (since that word has been used a lot in this piece) about the brain are tied to things (not facts) about the mind, experience or consciousness.

Chalmers argues that bridge laws are over and above the facts. This is Chalmers’ own take on bridge laws:

“Some might argue that explanation of any high-level phenomena will postulate ‘bridge laws’ in addition to a low-level account, and that it is only with the aid of these bridge laws that the details of the high-level phenomena are derived.”

Chalmers suggests (or states) that “in such cases the bridge laws are not further facts about the world”. That is, “the connecting principles themselves are logically supervenient on the low-level facts”. In other words, these connecting principles are not facts. (Alternatively, the statements about connecting principles aren’t factual.) Chalmers then gives an obvious and clear example of this: “the link between molecular motion and heat”. Heat simply is what’s called “mean molecular motion”. (Or: heat = mean molecular motion.) Having said that, there are things which can be said about heat which can’t be said about moving molecules. All talk of heat, nonetheless, can still “be derived from the physical facts”. Still, things said about heat are over and above the things said about (mean) molecular motion. What’s more, what’s said about heat doesn’t include “further facts about the world”.

This raises the question:

If not further facts about the world, then further… what?

Chalmers trumps all this fairly uncontroversial stuff with — as one might have guessed — an exception to his general rule: consciousness. In the case of consciousness (so Chalmers believes), consciousness is a “further fact[] about the world”. What’s more, consciousness is not (again) “logically supervenient on the low-level facts”. Consciousness may be empirically and contingently supervenient on low-level facts; though consciousness isn’t logically supervenient on them. That is, no physical facts about the brain (or otherwise) logically entail consciousness; and consciousness doesn’t logically entail any facts about the brain (or otherwise).

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Facts Matter: A Mouse’s Beliefs and its Conscious Experiences

Here’s another question from Chalmers:

“Does a mouse have beliefs?”

As stated in the introduction, Chalmers often mentions “stipulation”. That is, if we stipulate what we mean by the word “belief”, then the answer to that question must — at least in part — follow from the stipulation.

To simplify, if x, y and z constitute what it is for something to be a belief, then if a mouse displays x, y and z, then it has a belief. This is of course a simplified story. That’s because agreement will have to be made on x, y and z, and then on whether not x, y and z are necessary and sufficient for belief. But however complicated this story turns out, stipulation will still remain part of it. That is, do we believe that (as it were) beliefness (like aliveness) is something over and above the functional, structural and/or physical facts?

Chalmers is keen to accept the importance of stipulation when it comes to such decisions. He also believes — at least as I see it — that much that passes for metaphysics is merely verbal dispute. However, it’s still the case that in some cases (or in one case!) at least there’s a fact of the matter which makes some statements, concepts or theories plain wrong.

Take Chalmers’ own final question:

“Does a mouse have conscious experience?”

In this case, it isn’t all about stipulation or verbal dispute. That is:

“Either there is something that it is like to be a mouse or there is not, and it is not up to us to define the mouse’s experience into or out of existence.”

So it’s not always a case of all the debaters agreeing on the facts; though still disagreeing on what they say about the facts. This time — at least according to Chalmers — the debaters are also disagreeing about the facts. In this example, it’s about whether or not “a mouse [actually has] conscious experience”.

In the previous examples the debaters said different things about the facts; but agreed on the facts. Now the debaters disagree on the actual facts. What’s more, Chalmers believes that “we cannot stipulate [] away” whether or not the mouse has conscious experience or not.

The question is, then, whether or not Chalmers’ position on consciousness really is in a different ballpark to the previous disputes about computer viruses, mice having beliefs, books made out of tissues, bacteria which learn, etc. That is, is a “functional analysis” also acceptable in the case of a mouse’s experiences? Chalmers says “no”.

So my own final question is:

Why is the case of a mouse having — or not having — “conscious experience” so different to the cases already discussed?