Platonist Roger Penrose "Sees" Mathematical Truths

i) Introduction

ii) Does Penrose Go Beyond Mathematics?

iii) Gödel, Turing, Penrose

iv) Beyond Mathematical Platonism?

v) Seeing Truths

vi) Do Platonic Truths Stand Alone?

vii) Penrose’s Rationalism

viii) Laurence BonJour: A Rationalist of the 21st Century

vix) Conclusion: Is Roger Penrose Really a Platonist?

The following piece is about what the theoretical physicist and mathematician Roger Penrose has said about “seeing” certain mathematical truths. Penrose’s overall Platonic position is also discussed. Indeed the question as to whether Penrose actually has an overall Platonic position is also asked.

But before all that, let’s place Penrose’s position in some kind of context.

ii) Does Penrose Goes Beyond Mathematics?

Penrose has been very open-minded about (as it were) Platonic seeing when it comes to such things as “beauty” and “goodness”. Despite that, he’s never done any detailed work on any of these strictly philosophical issues. Much of what Penrose has said has been the result of interviewers pressing him on subjects which aren’t his speciality . (In most cases these have been attempts — by such interviewers — to get Penrose to backup their own prior religious or spiritual views — see here for a perfect example of this.)

One aspect of the wider context of Penrose’s Platonism concerns his deflationary position on “algorithmic thinking”. And, as a consequence of that position, his critical position on the possibility of strong artificial intelligence; as well as his controversial views on human consciousness.

And this is where the Austrian mathematician and logician Kurt Gödel inevitably enters the picture.

Let Penrose himself tell you about his first encounter with Gödel’s work and what effect it had on him. He wrote:

“Why did I believe that consciousness involves noncomputable ingredients? The reason is Gödel’s theorem. I sat in on a course when I was a research student as Cambridge, given by a logician who made the point about Gödel’s theorem that the very way in which you show the formal unprovability of a certain proposition also exhibits the fact that it’s true.”

What follows is perhaps more relevant to this piece. Penrose continued:

“[A]s long as you believe in the rules [of “any system of rules”] you’re using in the first place, then you must also believe in the truth of this [Gödel] proposition whose truth lies beyond those rules.”

And now for the relevant (as it were) clincher:

“This makes it clear that mathematical understanding is something you can’t formulate in terms of rules.”

This is where Platonic seeing comes to the rescue. Penrose believes that no machine (or computer) can have Platonic vision. That is, “we have a proposition that we can see [Penrose’s italics], by the use of insight, must actually be true”. However, “the given algorithmic action is not capable of telling us this”.

Penrose then goes into greater detail when he asks us this question:

“Why, then, can one not simply get a computer also to follow this Gödel argument and itself ‘see’ the truth of any new Gödel proposition?”

What’s more:

“The catch lies in ‘seeing’ that the Gödel argument, in any specific realization, has actually been correctly applied. The trouble is that the computer does not have a way of judging truth; it is only following rules. It does not ‘see’ the validity of the Gödel argument. It does not ‘see’ anything unless it is conscious!”

It may of course be asked how literally Penrose wants his readers to take his words “seen”, “see”, “seeing” and “vision”. After all, Penrose himself used scare quotes in the passage above. However, scare quotes can sometimes be somewhat ambivalent. On the one had, they can be used ironically or questioningly. (As Heidegger and Derrida had it, words can be used sous rature — i.e., “under erasure”.) On the other hand, even though some writers use scare quotes, that doesn’t automatically mean that their words are meant to be taken ironically (or not to be taken seriously). In Penrose’s case, it can be argued that the scare quotes simply signify that he’s aware that words like “see” are controversial within this precise context. However, that doesn’t mean that Penrose believes that they’re unacceptable or that they’re in some sense, say, metaphorical. (In all the other places I’ve read Penrose use these words, he doesn’t use scare quotes.)

iii) Gödel, Turing, Penrose

Of course this philosophical angle of Penrose is not all his own invention. Far from it. Gödel himself made philosophical comments about his own theorems. (This is to disregard the Gödel Industry; which applies his theorems to everything under the sun.)

In his ‘What is Cantor’s Continuum Problem’ of 1947, for example, Gödel explicitly made something (or much) of the fact that there’s a way of contacting “reality” other than through “sense perception”. (That said, even empiricists have acknowledged this; if with many additional clauses.) More precisely, Gödel used the words “mathematical intuition” to account for our (as it were) Platonic receptor.

So Alan Turing is a good counterweight to bring in here.

Although Turing accepted Gödel’s theorems, he didn’t also accept some of the things which were said to be consequences of those theorems. (Many see Turing’s Halting problem as the “computational equivalent” of Gödel’s first incompleteness theorem.) More specifically, Turing accepted that what Gödel called “intuition” is used in order to see the truth of a formally unprovable Gödel sentence. What he didn’t accept was that the brain and mind go beyond the “mechanical”. That is, Turing might well have asked Gödel how it is possible that non-mechanical intuition is carried out by a physically-embodied brain. (See Turing’s ‘Computing Machinery and Intelligence’ — 1950 — for a very clear account of Gödel’s theorems and why Turing believed that they’d been somewhat overstretched.)

One other argument Turing offered was that because the brain is so complex, it simply appears to transcend its mechanical (or rule-following) nature. He also argued that (what he called) “initiative” doesn’t require uncomputable steps. (See Andrew Hodges’ ‘The Logical and the Physical’.) However, a machine’s (or computer’s) computations could still go beyond any programmer’s programme. (See also Turing’s “randomizer”.)

All this meant that Turing didn’t conclude (i.e., from Gödel’s theorems) what Penrose later came to conclude about the human mind or consciousness. And it also meant that Turing was happy with the idea of what later came to be called (firstly in 1956) “artificial intelligence”.

iv) Beyond Mathematical Platonism?

I was fairly suspicious about the quote above because it was doing the rounds in the quote zoo on the Internet and I couldn’t find the source. (That is, the editors of such quotes websites were quoting other quotes websites in which they’d seen this quote… Then I came across this interview. The exact quote above can’t be found within it. However, Roger Penrose does come very close to saying it.

Despite the restricted scope (i.e., mathematics) of what has been said above, Penrose also seems to go beyond purely mathematical Platonism when he stated the following:

“[I] find words almost useless for mathematical [Penrose’s italics] thinking. Other kinds of thinking, perhaps such as philosophizing, seem to be much better suited to verbal expression. Perhaps this is why so many philosophers seem to be of the opinion that language is essential for intelligent or conscious thought!”

Like Plato, Penrose appears to glory in this escape from contingency. In this case, it’s the contingency of “words” and (no doubt) their lack of precision that must be escaped from… Or at least this is the case when it comes to mathematics.

Yet language, surely, is essential for Platonists too. That is, in order to become the Platonists that they are, language itself must have led their way in most/all of their philosophical directions. Indeed that’s even the case when it comes to mathematics.

Here again we also need to get our heads around what Penrose means by the word “visually”. It can be argued that Penrose would never have adopted and used these non-linguistic “concepts” if they weren’t first described to him in “words”. Sure, as with the a priori, we need to learn what the a priori is — and also to learn the words used in a priori statements — in order to have a priori “thoughts”. So this must mean that Penrose must be talking about what happens after the basic words and concepts are acquired. And what happens after is (he argues) something that’s completely non-verbal (or non-linguistic). So, yes, one has to know a posteriori what the words and symbols in the equation 2 + 2 = 4 mean. However, after that, the non-linguistic status of this truth remains unchanged.

As has just been stated about the a priori: we firstly need to learn the terms involved in this debate. However, once Penrose and other Platonists have acquired these words and symbols from a natural language, then perhaps they can “float free of the moorings” (to quote Kant on Plato) and rise into the Platonic realm.

v) Seeing Truths

So Roger Penrose often uses the words “see”, “seen” and “visualised” when it comes to certain mathematical truths (as well as, perhaps, other things). That is, he believes that many mathematical truths are seen to be true without being proved to be true. (In that simple sense at least, he’s simply putting Gödel’s position.)

Along with “seen”, Penrose also uses the words “insight” and “intuition”. For example he writes:

“[A] specific Gödel proposition — neither provable not disprovable using the axioms and rules of the formal system under consideration — is clearly seen [Penrose’s italics], using our insights into the meanings of the operations in question, to be a true [ditto] proposition!”

A useful and indeed apt technical term which captures Penrose’s claims is Paul Boghossian’s “flash-grasping”. The American philosopher defines his own term in the following way:

“Flash-Grasping: We grasp the meaning of, say, ‘not’ in a flash — prior to, and independently of, deciding which of the sentences involving ‘not’ are true.”

It may well be unfair to apply claims about the epistemology of logical terms (such as “not”, “and”, “or”, etc.) to what Penrose claims about certain mathematical truths. We’ll see later whether it’s possible to glide smoothly over from this area (as well as with the epistemology of the a priori) to Penrose’s seeing of mathematical truths.

Of course Penrose isn’t the only one to use words like “see” in the context of mathematical truths. For example, in the specific case of number theory and the Gödel sentence, G, the philosopher of logic Alasdair Urquhart uses the word “perception” (although it too is in scare quotes) in the following:

“Since we do seem to have a ‘clear and distinct perception’ of the notion of truth in number theory, it has often been argued that this demonstrates a clear superiority of humans over machines.”

And in the following paragraph Urquhart continues:

“[We], standing outside the formal system, and using our mathematical insight, can see that the sentence G is true, and so we can surpass the capacity of any fixed machine.”

However, in the above it can be said that Urquhart is (at least in part) putting other people’s positions. And since I’ve just quoted Urquhart, it’s also interesting that he questions Penrose’s claim that he can see that a Gödel sentence is true. He writes:

“The problem with the Lucas/Penrose argument … is that the key premise asserting that we can see the Gödel sentence to be true, remains undemonstrated. In fact, there are good reasons for thinking it to be false.”

In addition to the above, it also needs to be said that people may disagree as to exactly what it is they see. That is, one person may (platonically) see that p is true and another person may see that (the same) p is false. So even if we accept that there is Platonic seeing in both cases, that seeing alone doesn’t — and can’t — guarantee truth (or “truth without proof”).

So what about Penrose himself?

What does Penrose mean by “seen” here? Does he simply mean understand? Is it that we see the “meanings of the operations” simply because we understand them? That said, Penrose also stresses the fact that he “visualises” these things. So do people visualise meanings?

Of course all this may boil down to the simple fact that Penrose isn’t using the word “see” literally. (I mentioned scare quotes earlier.) Yet that still raises two questions:

1) Why does Penrose use the word “see”?

2) What does he mean by “see”?

Penrose also uses the word “sensing”. (Don’t we also sense when we see?) In this instance, Penrose goes beyond seeing the truth of a Gödel sentence and starts using much more modal and clearly Platonic ways of speaking. Indeed he partly explains what he means by “seeing” here:

“[]I believe consciousness to be closely associated with the sensing of necessary truths — and thereby achieving a direct contact with Plato’s world of mathematical concepts.”

There is a reason (at least within this specific context) why Penrose stresses Platonic sight. As stated in the introduction, it’s because he believes that “[sensing necessary truths] is not an algorithmic procedure”. 

vi) Do Platonic Truths Stand Alone?

In terms of looking at things epistemologically again, is it the case that Penrose sees Platonic truths because they “derive their evidence from themselves” (as Laurence BonJour puts it about a priori claims — see later)? In other words, is the proposition/equation/sentence itself all that’s required and nothing more? Yet surely this doesn’t work in terms of a mathematical theorems and especially not for a Gödel sentence. That’s because such things come at the end of a lot of reasoning, deductions, inferences, etc. which involve other propositions/equations/axioms/etc.

So it should be said (in strict accordance with the Penrose quote above) that what is seen is not, for example, the truth of Gödel sentence (G) itself. Instead, Penrose tells us that “the meanings of the operations in question” are seen. That is, firstly the meanings of the operations are seen, and only then does that lead to also seeing the truth of the Gödel sentence. 

However, it can also be said that the truth of sentence G is seen precisely because the meanings of the operations (which led to it) were also seen. (Basically, if you see x, then you must also see y.)

One way of looking at this is the distinction made by philosophers between “relative” and “absolute” truths (or, more often, relative and absolute modalities) as found in logical deduction. 

Absolute truths are true in and of themselves (as in an a priori or analytic manner, which will be discussed later). Relative truths, on the other hand, are a consequence of a previous set of axioms/statements/theorems/etc. Thus if the truths which Penrose can see are merely relative truths (in this strict logical sense), then how can we make sense of seeing within this relative context? That is, what is it to see truth T if T is actually a consequence of a further set of axioms/statements/theorems/etc. which may also be taken to be true (though not necessarily — they can simply be taken as given)?

This must mean that such theorems don’t have the same status as so-called analytic truths, such as:

All married men are bachelors.

Sure, you need to know the meaning of the terms and the fact that “married men” and “bachelors” are synonyms. But apart from that, there are no explicit (though they may be tacit) processes which lead towards one’s knowledge that the statement above is true.

So what about this? -

2 + 3 = 5

Laurence BonJour (more of whom later) says that the truth of the above is “guaranteed by its content”. That means that “understanding the proposition is a sufficient condition for recognising its truth”. Basically, as BonJour adds, this proposition is not “made true by experience”; but only “by content alone”. 

vii) Penrose’s Rationalism

In many respects it would be just as accurate to classify Penrose as a rationalist (if with qualifications) as it would be to class himself as a Platonist. (Of course Platonism is a kind of rationalism.) And Penrose’s positions have a very rationalist feel to them. Indeed we can see similarities between Penrose’s position and statements found in Rene Descartes’ work — who was himself a rationalist.

So here’s Descartes himself putting his classic rationalist position:

“[I]f it could ever happen that a thing which I conceived so clearly and distinctly could be false… I can establish as a general rule that all things which I perceive very clearly and very distinctly are true.”

And elsewhere Descartes also writes:

“Clear and distinct perceptions are so coercive in their effect upon the mind that the mind cannot help assenting to them as true at the time it has such perceptions.”

It needs hardly be said that Descartes uses the words “perceive” and “perceptions” in the above. That is, he perceived certain truths. But to be fair (if that’s the right word) to Penrose, Descartes wasn’t talking about mathematical truths in the above. He was primarily talking about “the thing which thinks”. And, elsewhere, Descartes claimed to have “clearly and distinctly” perceived truths about God, the possibility of the mind existing without the body and suchlike. Penrose, of course, has never really ventured into any of these areas. (He has classed himself as an “atheist”.)

In addition to all that, it’s very clear that Penrose can’t be a strict (or complete) rationalist for the simple reason that he places a lot of emphasis on observations, scientific experiments, predictions, etc. Penrose even comes close to accusing string theorists of being Platonists in his Road to Reality and his most recent book Fashion, Faith and Fantasy in the New Physics of the Universe. He does so because such string theorists appear to have a complete trust in their “consistent” and purely mathematical theories — theories which aren’t backed up by (unique) experiments or predictions. 

Yes; Penrose is also a mathematical physicist. Then again, Descartes (along with Leibniz and Spinoza) too had a great respect for science and experiment and indeed his rationalist work was seen (by himself) to be but a means of securing the science of his day. 

viii) Laurence BonJour: A Rationalist of the 21st Century

Let’s bring things more up to date and move beyond Plato, Descartes and other dead rationalists. Take the American philosopher Laurence BonJour.

BonJour’s rationalism is encapsulated in his position on the a priori. The following is what he says on that subject:

“[I]f we never have a priori reasons for thinking that if one claim or set of claims is true, some further claim must be true as well, then there is simply nothing that genuinely cogent reasoning could consist in. In this was, I suggest, the rejection of a priori reasons is tantamount to intellectual suicide.”

As it is, BonJour describes himself as a “rationalist”. And, clearly, he’s also well aware of the criticisms of rationalism. For example, in reply to the Australian philosopher Michael Devitt, Bonjour talks of Devitt’s

“allegations that rationalism is ‘objectionably mysterious, perhaps even somehow occult’…”

He concludes by saying that he find these allegations “very hard to take seriously”.

So what else does Devitt have to say on BonJour? The following:

“BonJour is an unabashed old-fashioned rationalist (apart from embracing the fallibility of a priori claims). He rests a priori justification on ‘rational insight’: ‘a priori justification occurs when the mind directly or intuitively sees or grasps or apprehends… a necessary fact about the nature or structure of reality’…”

Sure, it may not be such a good thing to quote Philosopher X on Philosopher Y — especially if they take diametrically opposed positions on the same issue. In any case, there are certain elements in the passages above that don’t entirely square with Penrose’s own positions.

For example, how strong and clear is Penrose himself on the “fallibility” of his seeings of mathematical truth? (Note: If BonJour accepts the possibility of a priori fallibility, then what about the possibility that all a priori claims are fallible and/or indeed false?)

In addition, are Penrose’s claims necessarily applicable to “the nature or structure of reality”? Or are they simply about mathematics/mathematical systems? Yes, it’s true that mathematics must be part of reality; though many of BonJour’s a priori claims are literally about the physical world itself.

So what does BonJour’s rationalism amount to? Take the following passage:

“[A]n intuition is a semi-cognitive or quasi-cognitive state, which resembles a belief in its capacity to confer justification, while differing from a belief in not requiring justification itself.”

And elsewhere:

“[I]n the most basic cases such reasons result from direct or immediate insight into the truth, indeed the necessary truth, of the relevant claim.”

So, like Penrose, BonJour uses the phrase “necessary truth”. That is, BonJour ties necessity to truth. Again, in BonJour’s own words:

“Devitt seems to me to be simply rejecting the idea that merely finding something to be intuitively necessary can ever constitute in itself a reason for thinking it is true…”

Indeed BonJour goes further by stating the following:

“[A priori] insights at least purport to reveal not just that the claim is or must be true but also, at some level, why this is and indeed must be so. They are thus putative insights into the essential nature of things or situations of the relevant kind, into the way that reality in the respect in question must be.”

There’s just been a lot of focus on the epistemology of seeing truth. So here’s another problem from epistemology on a priori (if not Platonic) seeing from the American philosopher James Van Cleve. He writes:

“If the foundationalist claims that his principles are immediately justified, then what it to prevent, let us say, a [religious] revelationist from claiming the same status for a principle to the effect that if S has an ostensible revelation that P, then S is justified in believing that P?”

(Of course it doesn’t help us much when Van Cleve concludes by saying that “[s]ome claims to immediate justification are spurious”. After all, as stated earlier in regards to a priori “fallibility”, if some cases of “immediate justification” are “spurious”, then perhaps all of them are.)

The question now is: 

How applicable is all the above to Penrose’s own seeings of mathematical truths?

ix) Conclusion: Is Roger Penrose Really a Platonist?

It can be argued (or seen) that Roger Penrose doesn’t really extend his Platonic vision much (or at all) beyond mathematics. Having said that, his strong and controversial positions on consciousness and artificial intelligence can indeed be seen to be going beyond the mathematics. Nonetheless, Penrose would no doubt argue that these positions are largely (or even wholly) derived from the maths. 

It’s often said that the general “Platonic position” on mathematics is the “consensus position” among mathematicians — and indeed among many other people outside mathematics. However, it must also be said here that most mathematicians don’t philosophise in this way about their own subject. (Though some mathematicians most certainly do.) In addition, the acceptance of Gödel’s theorems is almost universal. So too is the notion of mathematical intuition. (Here again it must be said that not many mathematicians will use these terms.) So it’s when Penrose extrapolates from these Platonic and Gödelian positions that he loses the consensus. For example, not many scientists or philosophers accept his very particular take on consciousness. And as for his stance against (strong) artificial intelligence, that too has received a large amount of criticism from many different quarters.

And from a strictly philosophical (or epistemological) point of view, Platonic seeing comes up against many hurdles; many of which (as discussed above) have been applied to the positive (rationalist) positions on the a priori in epistemology. In addition, cognitive scientists (of various kinds) will also have many things to say about Platonic seeing. 

Yet, despite all that, it’s still the case that many people’s intuitive (as it were) position on mathematical intuition will be to claim that we do indeed immediately and (platonically) see the truth of, say, the equation 2 + 2 = 4. But where does that possibility (or reality) take us?

Finally, it can be said that Roger Penrose can indeed be seen as a rationalist — but only in very limited respects (i.e., when it comes to his position on mathematics). Yet if Penrose is a rationalist only in such limited respects, then how can he be a rationalist at all? In other words, were Plato, Descartes, Leibniz and Spinoza rationalists only in limited respects? And, as a further consequence of this, can it also be said that Penrose is a Platonist only in limited respects? After all, Plato himself wasn’t a Platonist only in limited respects.

David Chalmers' Unanswerable Hard Question

i) Introduction

ii) Brute Facts?

iii) David Chalmers and Christof Koch

iv) More Hard Questions?

v) Conclusion

The Australian philosopher David Chalmers is well-known for asking his “hard question”. It (sometimes) goes like this:

“Why should physical processing give rise to a rich inner life at all?”

Perhaps this question is similar to the following:

Why are the laws of physics (or the constants of nature) the way they are?

But what if these questions don’t have answers (or solutions)? What if the questions themselves are suspect? Despite stating that, even if a question may not have an answer; reasons or explanations still need to be given as to why that’s the case.

Compare the questions above to another possibly unanswerable (if ironic) question raised by the well-known theoretical physicist Richard Feynman. He recalled:

“You know, the most amazing thing happened to me tonight. I saw a car with the license plate ARW 357. Can you imagine? Of all the millions of license plates in the state, what was the chance that I would see that particular one tonight? Amazing!”

This passage from Feynman can be reformulated as this simple question:

Of all the millions of license plates in the state, why did I see that particular one tonight?

Of course this question isn’t in the same ballpark as the question “Why do physical states give rise to experience?” (or “Why are the laws of physics and constants of nature the way they are?”); though it may be on the borders of that question.

It’s not weird that Feynman should have seen that particular number plate. So it may not be such a deep mystery that a physical state (or states) should give rise to an experience or that the laws of physics (or the constants of nature) have some kind of nature (or the values that they do have).

Moreover, perhaps there’s no deep answer — other than mundane facts about probabilities — to the question as to why Feynman should have seen that number plate. Similarly with experience arising from the physical. That is, beyond the fact that these things are the way they are, there may be nothing more to say.

Yet David Chalmers himself does seem to be committed to the “principle of sufficient reason” in that he believes that his hard question about the physical/brain-consciousness relation can (or must) be answered — even if only “in principle” (or in the future). However, Chalmers doesn’t believe that this is the case with all questions. 

For example, Chalmers seems to reject this question:

Why is there matter, space-time, gravity, etc. in the first place?

Or, in Chalmers’ own words, he tells us that

“(n)othing in physics tells us why there is matter in the first place, but we do not count this against theories of matter”.

That means that Chalmers himself may accept an end to questions (hard or soft) when it comes to what he calls “the fundamentals of physical theory”. That is, he argues that the question of “why there is matter in the first place” may well be illegitimate — at least from a position within physics (i.e., it may be — or is — a fit subject for philosophy or theology).

In the same vein, can’t we reject the need to see the laws of physics or the constants of nature (which underpin spacetime, matter, gravity, etc.) as having either a necessary or accidental (or contingent) nature? More importantly, can’t we question the assumption that these questions can be answered? In other words, the following question may be bogus:

Why are the laws of physics (or constants of nature) the way they are rather than another way?

Thus, just as physics “does not tell us why there is [matter] in the first place”, so it may not be able to tell us why the laws of physics are the way they are. (Or, alternatively, physics can’t — or doesn’t — tell us why the constants have the values which they do have.)

So David Chalmers’ position (which is the same as most physicists) is that we must begin with the fundamental laws and constants of nature. Such things are deemed primitive. That is, they can’t be “deduced from more basic principles”. This means that Chalmers has a position on physics that seems to go against his own hard question on the nature of consciousness (or experience).

Having said all that, Chalmers does indeed concede the possibly that an “epistemically primitive connection between physical states and consciousness” may be a “fundamental law”. So doesn’t that basically mean that we can’t (or simply may not) be able to explain that connection between the physical and consciousness? Perhaps there’s literally nothing to explain because of its very primitiveness.

Alternatively, is this ostensible lack of an explanation of the physical-consciousness relation a result of the fact that (according to the philosopher John Heil) “our mental and physical concepts are too far apart to be unified under a single theory”? Perhaps the mind-body (or body-mind) relation is just too simple, fundamental or basic to be explained by any theory — mental or physical. Perhaps there’s literally nothing to explain. Indeed isn’t this one of the definitions of the words ‘brute fact’?

Brute Facts?

John Heil goes on to say:

“Once you reach a basic level, however, explanation runs out: things behave as they do because they are as they are, and things with this nature just do behave in this way. Explanation works, not because all explanation is traceable to self-explaining explainers. Explanation works by reducing the complex to the less complex. At the basic level the behaviour of objects cannot be further explained.”

Indeed when physical explanations do come to an end, then we reach a point when

“things behave as they do because they are as they are, and things with this nature just do behave in this way”.

That is, we can’t explain or ask questions anymore. However, it’s of course the case that nothing can stop us from asking these questions — even if they are unanswerable.

In terms of brute facts again.

The acceptance of brute facts in physics may not help us when it comes to the nature of the brain-consciousness relation. The Australian philosopher J.J.C. Smart, for example, argued against the acceptability of this analogy. In his ‘Sensations and Brain Processes’ (1959), he wrote:

“It is sometimes asked, ‘Why can’t there be psycho-physical laws which are of a novel sort, just as the laws of electricity and magnetism were novelties from the standpoint of Newtonian mechanics?’ Certainly we are pretty sure in the future to come across ultimate laws of a novel type, but I expect them to relate simple constituents… I cannot believe that the ultimate laws of nature could relate simple constituents to configurations consisting of billions of neurons (and goodness knows how many billions of billions of ultimate particles) all put together for all the word as though their main purpose was to be a negative feedback mechanism of a complicated sort.”

In other words, the arrival (or emergence?) of consciousness would be required to be a relation not between the very simple and the (slightly) less simple; but between the hugely complex (i.e., the brain or its individual parts) and the simple (i.e., a conscious state).

Heil offers a similar argument about the possibility of brute fact(s) when it comes to the physical-consciousness relation. Though, whereas J.J.C. Smart states a relation between the brain’s complexity and a simple mental state/experience; Heil makes a connection between a complex brain state and a “complex qualitative experience”. Heil writes:

“This alleged brute fact differs from brute facts concerning electrons because it connects something complex — a qualitative experience — with something very complex — a brain process, for instance, involving millions (billions?) of particles.”

To conclude. Heil again questions the status of what we may call the Brute Fact Theory of Consciousness:

“Perhaps there are such brute facts, but if there are, they are very different from the kinds of brute fact we expect to find in mapping the nature of the material world.”

If they are different (let alone very different), then what right have we to make comparisons between the ostensible physical-consciousness brute fact and those found by particle (or quantum) physicists?

David Chalmers and Christof Koch

Francis Crick and Christof Koch.

Chalmers, on the other hand, does reject any physical-to-consciousness brute fact. In other words, he believes that there are questions about this relation which need to be answered. More technically, Chalmers says that

“Crick and Koch’s theory gains its purchase by assuming a connection between binding and experience, and so can do nothing to explain that link”.

So let’s reformulate Chalmers’ words as a simple question:

What is the connection (or link) between binding and experience?

What does Chalmers mean by the word “explain” (as used in the quote above)? What kind of explanation would make him happy? Is there even a possible (or hypothetical) explanation which could be conjured up (care-of speculative philosophy or metaphysics) which would make him happy or satisfied? Let’s think about it. Think about any possible arguments (or data) which could explain the link between the physical and experience. What would they look like? What could they look like?

Chalmers — elsewhere — makes much of “conceivability” leading to “metaphysical possibility”. This means that if we can conceive of such a link between the physical and experience, then that link would be metaphysically possible. So, go ahead, conceive of such a link. What, precisely, have you conceived?

Does Chalmers (kind of) admit that such a link can’t be found because it can’t even be conceived of in the first place? It’s hard to say. However, he does quote Christof Koch when he said the following:

“‘Well, let’s first forget about the really difficult aspects, like subjective feelings, for they may not have a scientific solution.’”

It’s true here that Koch refers to a “scientific solution” — not a philosophical or metaphysical one. However, would a philosophical or metaphysical solution be any more forthcoming than a scientific one? What would it look like?

So is the question

Why do the oscillations give rise to experience?

even a good question? Is there an answer to this — even in principle? What kind of answer is Chalmers looking for? He isn’t asking the following question:

How do oscillations in the brain give rise to experience?

That question could be answered in physical or causal terms. Though this too is problematic in that, for a start, we’d need to be clear about the word ‘how’. In addition, don’t (at least some) how-answers presuppose (at least some) why-questions? Similarly, don’t (at least some) why-questions also presuppose (at least some) how-answers?

As for Chalmers’ own why-question (rather than his how-question), perhaps there isn’t an answer.

More Hard Questions?

To help matters here, let’s tackle some questions which can’t be answered. For example, take this question:

Why is water H₂0?

That is really the same as this question:

Why is H₂0 actually H₂O? (Or: Why is water actually water?)

However, that’s not true of this Chalmers-like question:

In terms of causality, we can’t ask

Why does a collection of H₂0 molecules cause (or bring about) water?

because they’re one and the same thing. However, a question can be asked about the physical bringing about — or causing — the mental. Then again, take this different kind of question about water:

Why is water H₂0 and not something else?

This question may be bogus. That is, we can now reply:

If water were something else (say, the fictional O₃Z), then it wouldn’t be water at all.

Then again, the phenomenal properties of O₃Z could be the same as water; though it wouldn’t be water as it’s scientifically known to us. (Though what if water’s phenomenal properties matter — or matter more — than molecular structure? Why is molecular structure always paramount?)

In addition, what if one is an identity theorist? Or what if one is a conceptual pluralist and ontological monist who believes that the mental and the physical are two aspects of the same substance? Then the question

Why does the physical bring about (or cause) the mental?

would be as nonsensical as asking

Why does H₂O bring about (or cause) water?

Conclusion

So, to summarize. When Chalmers asks,

“Why do the oscillations give rise to experience?”

we can reply:

Why does anything give rise to experience?

Indeed it can be said that whatever someone posits as an explanation or an answer, Chalmers could ask the very same question. Could a neuroscientist, physicist or philosopher cite any fact about the physical (or the brain) which would make Chalmers happy? In other words, Chalmers can ask his question no matter what anyone says about the brain or the physical and its relation to consciousness/experience. 

Therefore the question

Why does physical x give rise to experience?

can always be asked. Indeed Chalmers may keep on asking his Hard Question.

Scientists vs. Philosophers: A Debate (on YouTube) Between Physicists and Philosophers

i) Introduction

ii) Stephen Hawking

iii) Lawrence Krauss and Neil DeGrasse Tyson

iv) Philosophical Physicists

v) Philosophy and/or Prediction?

This discussion is hosted by the producer and writer Steve Paulson. It includes the American philosophers David Z. Albert (on the far right) and Jim Holt (in the middle); as well as the physicist Neil Turok (to the immediate right of the host).

Introduction

The video opens up with the host (Steve Paulson) asking this question:

“Why is it that so many physicists are bashing philosophers nowadays?”

Is that true? Stephen Hawking certainly had a go at philosophers and philosophy on more than one occasion. The host himself mentions Hawking saying that “philosophy is dead”. So why “dead”? It’s because (Hawking believed) “philosophers haven’t kept up with physics” (the host’s words). The following is what Hawking himself said (which isn’t quoted in full in the video):

“Traditionally these are questions for philosophy, but philosophy is dead. Philosophy has not kept up with modern developments in science, particularly physics. Scientists have become the bearers of the torch of discovery in our quest for knowledge.”

But let’s not single out Hawking. Here’s the biologist and naturalist Edward O. Wilson saying almost exactly the same thing:

“It appears to me that professional philosophers have not kept up with the foundational disciplines of neuroscience, behavioural genetics, and evolutionary biology, and as a result they have surrendered their franchise to the scientists. The scientists, not the philosophers, now address most effectively the great questions of existence, the mind, and the meaning of the human condition. This surrender seems to be permanent, and professional philosophers have begun a diaspora into other vital and challenging disciplines that include theoretical neuroscience, evolutionary theory, intellectual history and bioethics.”

In response to all that, and as David Albert puts it in the video, one gripe of physicists is that philosophers aren’t doing physics. Albert counters that by saying, “What the hell have physicists done for music lately?” (His point being that physicists are criticising apples for not being oranges.)

Anyway, having quoted the anti-philosophy stuff above from Stephen Hawking and E.O. Wilson, many philosophers themselves have claimed that philosophy is dead (if not in those precise words). Why “dead”? Again, it’s because philosophers haven’t kept up with physics/science. Ontic structural realists are a clear example of this. (Though even they don’t have every philosopher under the sun in mind.) And a few other philosophers (such as Daniel Dennett — see here) are also critical of philosophers for the same reasons cited by scientists.

One can understand how certain physicists are irked by philosophers if David Albert is correct when he states (in the video) the following:

“There have been instances of philosophers telling physicists that they’re not doing their jobs properly.”

That may explain things — at least to some extent. So take on board the following passage (which is in tune with what Albert has just said) from the philosopher of science, Wesley Salmon. He wrote:

“While the philosopher of science may be basically concerned with abstract logical relations, he can hardly afford to ignore the actual methods that scientists have found acceptable. If a philosopher expounds a theory of the logical structure of science according to which almost all of modern physical science is methodologically unsound, it would be far more reasonable to conclude that the philosophical reasoning had gone astray than to suppose that modern science is logically misconceived.”

The host also says that physicists claim that “philosophers don’t add any knowledge to the world”. That’s very ironic because it was philosophers themselves (e.g., the logical positivists and Ludwig Wittgenstein — see here) who first made precisely that point in the 1920s and 1930s.

Yet this also means that in order for physicists to claim that “philosophy doesn’t add any knowledge to the world”, they must do some philosophising themselves. That is:

i) Such physicists need to explain what they mean by “knowledge”.
ii) Such physicists need to tell us why philosophical claims aren’t examples of knowledge.
iii) Such physicists need to tell us why scientific knowledge is the only kind of knowledge.
iv) And such physicists need to tell us why they give scientific knowledge (or science itself) such a preeminent status.

None of the positive or negative answers to those questions will be scientific in nature. One would hope, then, that physicists will never argue that such questions shouldn’t even be asked. However, if any physicists did argue (or simply believe) that such questions shouldn’t be so much as asked, then that extreme position would itself need to be philosophically defended and backed up. And if such scientists didn’t defend it (or if they believe that they aren’t required to defend it), then that somewhat abolutist, elitist and arrogant stance will itself — again — need a philosophical defence. And despite all that, scientists like Lawrence Krauss (see later) and the British developmental biologist Lewis Wolpert (not mentioned in the video, though extremely anti-philosophy — see here) may deny that too.

In the video Jim Holt also makes the point that much of this philosophy “bashing” is itself philosophical. Indeed he says that about what Neil Toruc (the physicist to his left) himself had just said about philosophy. So, if physicists want to stay well clear of philosophy, then they better simply “shut up and calculate” (i.e., rely entirely on the mathematics/science, rather than, say, publish “popular science” books). Yet even in that case that too would require a philosophical defence and would include closet (or implicit) philosophical positions.

Stephen Hawking

Stephen Hawking is actually a bad example of an anti-philosopher. That’s for the simple reason that what he said about philosophy is very naive. More importantly, Hawking himself offered the world his own philosophical position on physics; which he called model-dependent realism. Now how perverse is that?

So here’s a taster of Hawking’s own philosophy:

“There is no picture- or theory-independent concept of reality. Instead we will adopt a view that we will call model-dependent realism: the idea that a physical theory or world picture is a model (generally of a mathematical nature) and a set of rules that connect the elements of the model to observations. This provides a framework with which to interpret modern science.”

Sure, it might have been the case that Hawking didn’t see his model-dependent realism as a philosophical position. He might have seen it as a simple description of the facts and methodologies of physics. But that too would have been monumentally naïve. In addition, if Hawking really classed himself as “a positivist” (as David Albert claims in the video), then his rejection of philosophy was even more ridiculous and/or naïve.

Ironically, it can be just as easily be said that physics is dead because physicists like Hawking haven’t kept up with philosophy. After all, historically it was the case that nearly all scientific advances had their roots in philosophical ideas and theories. Albert Einstein himself owed a strong debt to both Ernst Mach (mentioned by David Albert) and Immanuel Kant (as well as others). Even Isaac Newton was well-schooled in philosophy and his own physics was called “natural philosophy”.

Lawrence Krauss and Neil deGrasse Tyson

It’s interesting that the anti-philosophy physicists the host mentions (apart from Hawking) haven’t done any important work in physics. For example, he mentions the “cutting remarks” of Neil deGrasse Tyson and Lawrence Krauss. Now, no doubt Krauss and Tyson originally did do some work in physics. However, they aren’t known for that work. They’re known almost exclusively for being “popularisers of science”. And as a consequence of that, it can now be said that the revolutionaries of physics have always been both philosophically inclined and aware of much philosophy. I would suggest that Kraus and Tyson, on the other hand, are aware of almost zero contemporary philosophy and they probably know very little about dead philosophers too.

Having said that, if Krauss and Tyson (along with Hawking) already believe that “philosophy hasn’t kept up with science” (and therefore that philosophy has nothing to offer science/physics), then no wonder they have such a naïve view of philosophy. Krauss and Tyson are taking part in some kind of self-fulfilling prophecy here. That is:

i) Because Kraus and Tyson already believe that philosophy has nothing to offer science,
they never read philosophy.
ii) And because they never read philosophy,
they consequently believe that philosophy has nothing to offer science.

Thus all Krauss and Tyson are showing us here is their own ignorance of philosophy: they aren’t showing us that philosophers are ignorant of science. So, as already stated, one simply gets the impression (which can be backed up with fact) that people like Krauss and Tyson simply haven’t read much contemporary philosophy. Indeed I suspect that they don’t even know about much contemporary philosophy. (Jim Holt mentions the fact that when the philosophy of science is brought to the attention of scientists, they always say: “Oh, you mean Karl Popper?”) So, in that case, why do these anti-philosophy physicists believe what they believe about philosophy?

Philosophical Physicists

There have been a few other critical remarks about philosophers from physicists; though not as many as you may think. The opposite is in fact often the case. There have been many philosophical physicists. Having said that, being a philosophical physicist doesn’t necessarily mean that such a physicist must also be a big fan of philosophy (i.e., that he keeps bang up to date). Many physicists only ever mention dead philosophers and not contemporary ones. (Einstein, for example, was strongly inspired by Spinoza; though perhaps not so strongly in his purely scientific work.) On some occasions, the only “philosophers” some physicists rate are philosophical physicists, not philosophical philosophers.

In terms of contemporary and rather less recent philosophical physicists, we have Lee Smolin, Roger Penrose, Carlo Rovelli, Murray Gell-Mann, Julian Barbour, Paul Davies, Freeman Dyson, John Wheeler, Leonard Susskind, Martin Rees, Steven Weinberg, etc. But if we go back in history, there have been many other philosophical philosophers (from Isaac Newton to Niels Bohr); many of whom were very knowledgeable about philosophy.

Philosophy and/or Prediction?

If (as David Albert says, ironically, in the video) some/most physicists believe that “physics is all about predicting the position of pointers” (not “how the world is” or “what the world is like”), then the layperson is probably on the philosophers’ side. (If all philosophers can be lumped together.) Having said that, physicists may have philosophical reasons as to why physics is all about prediction. Alternatively and as stated, that position may be philosophical in itself. That is: 

If the “world as it is” is — by definition — out of reach, then emphasising the importance of prediction can be a very philosophical position to take. (Of course this may not be the reasoning of many physicists — though it could be.)

But is all this really about quantum mechanics? After all, since Niels Bohr and Werner Heisenberg in the mid-1920s, physicists themselves have being saying that they can’t tell us “what the world is like” (to use Albert’s words). All they can tell us about are observations, experimental tests, measurements and, yes, predictions. But that lack of access to the quantum realm itself requires both a philosophical defence and a philosophical explanation. Indeed it has received such things — from both physicists and philosophers.

And since quantum mechanics has just been brought up, it also needs to be said that all the “interpretations” of quantum mechanics are — almost by definition — philosophical. That is, they’re philosophical precisely because they’re interpretational. (David Albert cites “Everettian interpretations” and the “measurement problem”.)

So is physics really “all about prediction”? Many dispute this — including some physicists. Yet, ironically, one philosopher believed that physics is (more or less) all about prediction. That philosopher was W.V.O. Quine; who (in his ‘Two Dogmas of Empiricism’) wrote:

“As an empiricist I continue to think of the conceptual scheme of science as a tool, ultimately, for predicting future experience is the light of past experience. Physical objects are conceptually imported into the situation as convenient intermediaries — not by definition in terms of experience, but simply as irreducible posits comparable, epistemologically, to the Gods of Homer.”

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