Blimey. Nothing here since mid-September. What’s happened? I’ve been running around from Austria to South Africa to Turin to Armenia to Austria to Netherlands and finally to Scotland. One fine masterclass after another. When I’m travelling like this my creative writing juices dry up.

Plus I’ve been grappling with my philosophy class with the University of Buckingham. It’s all so hard.

Take (for example) this week’s subject: Logic. You might think that the propositions a = a and a = b are as simple as it gets. What might be said about them?

But no. Gottlob Frege:

a = a and a = b are obviously statements of differing cognitive value; a = a holds a priori and, according to Kant, is to be labeled analytic, while statements of the form a = b often contain very valuable extensions of our knowledge and cannot always be established a priori. The discovery that the rising sun is not new every morning, but always the same, was one of the most fertile astronomical discoveries. Even today the identification of a small planet or a comet is not always a matter of course.

Now if we were to regard equality as a relation between that which the names ‘a’ and ‘b’ designate, it would seem that a = b could not differ from a = a (i.e. provided a = b is true). A relation would thereby be expressed of a thing to itself, and indeed one in which each thing stands to itself but to no other thing.

What is intended to be said by a = b seems to be that the signs or names ‘a’ and ‘b’ designate the same thing, so that those signs themselves would be under discussion; a relation between them would be asserted. But this relation would hold between the names or signs only in so far as they named or designated something. It would be mediated by the connexion of each of the two signs with the same designated thing. But this is arbitrary.


He distinguishes between the sense of an expression and the reference:

It may perhaps be granted that every grammatically well-formed expression representing a proper name always has a sense. But this is not to say that to the sense there also corresponds a reference.

The words ‘the celestial body most distant from the Earth’ have a sense, but it is very doubtful if they also have a reference. The expression ‘the least rapidly convergent series’ has a sense; but it is known to have no reference, since for every given convergent series, another convergent, but less rapidly convergent, series can be found. In grasping a sense, one is not certainly assured of a reference.

And so on, deep into conceptual rabbit-holes.

Anyway, I have written a first short paper to chance my arm in such things. What is a category? Here it is for your edification.

* * * * *

Descartes, Ryle, Categories, Mistakes

Gilbert Ryle’s The Concept of Mind purports to demolish as a ‘category mistake’ the strong distinction identified by Descartes between Body and Mind. Does Ryle succeed?

In the second of his Meditations on First Philosophy[1] René Descartes pondered his existence. He concluded that whereas he might doubt that almost anything in the world including his own body existed, he could not doubt that his thinking existed: the very act of thinking could never be a deception:

What of thinking? I find here that thought is an attribute that belongs to me; it alone cannot be separated from me … I am, however, a real thing and really exist; but what thing? I have answered: a thing which thinks.

The Introduction emphasised the significance of this point:

And finally we should conclude from all this, that those things which we conceive clearly and distinctly as being diverse substances, as we regard mind and body to be, are really substances essentially distinct one from the other …

We cannot conceive of body excepting in so far as it is divisible, while the mind cannot be conceived of excepting as indivisible. For we are not able to conceive of the half of a mind as we can do of the smallest of all bodies; so that we see that not only are their natures different but even in some respects contrary to one another.

Hence Descartes’ far-reaching conclusion about what his mind is:

… body, regarded generally, is a substance, which is the reason why it also cannot perish, but that the human body, inasmuch as it differs from other bodies, is composed only of a certain configuration of members and of other similar accidents, while the human mind is not similarly composed of any accidents, but is a pure substance … From this it follows that the human body may indeed easily enough perish, but the mind [or soul of man (I make no distinction between them)] is owing to its nature immortal.

Thus Descartes presents what is now known as ‘substance dualism’. Mind and Body are both substances but they are necessarily distinct substances.

308 years later, Gilbert Ryle in his introduction to The Concept of Mind[2] launched all-out attack on this way of looking at human life and thought:

Somewhat as the faces of coins are either heads or tails, or somewhat as living creatures are either male or female, so, it is supposed, some existing is physical existing, other existing is mental existing. It is a necessary feature of what has physical existence that it is in space and time; it is a necessary feature of what has mental existence that it is in time but not in space …

Direct access to the workings of a mind is the privilege of that mind itself; in default of such privileged access, the workings of one mind are inevitably occult to everyone else …

Such in outline is the official theory. I shall often speak of it, with deliberate abusiveness, as ‘the dogma of the Ghost in the Machine’. I hope to prove that it is entirely false, and false not in detail but in principle. It is not merely an assemblage of particular mistakes. It is one big mistake and a mistake of a special kind. It is, namely, a category-mistake. It represents the facts of mental life as if they belonged to one logical type or category (or range of types or categories), when they actually belong to another.

Ryle gives examples of different ‘category mistakes. A visitor who sees plenty of colleges, laboratories and libraries in Oxford but asks ‘But where is the University?’ A child watches a military parade and after seeing the marching squadrons and battalions asks ‘But where is the division?’ Someone asks who in a cricket team is responsible for team-spirit.

Ryle claims to identify the specific mistakes happening here:

These illustrations of category-mistakes have a common feature which must be noticed. The mistakes were made by people who did not know how to wield the concepts ‘University’, ‘division’ and ‘team-spirit. Their puzzles arose from inability to use certain items in the English vocabulary.

The theoretically interesting category-mistakes are those made by people who are perfectly competent to apply concepts, at least in the situations with which they are familiar, but are still liable in their abstract thinking to allocate those concepts to logical types to which they do not belong.

* * * * *

Ryle’s pummellings of Descartes are many and rambunctious. But are they clear?

Ofra Magidor argues in her book Category Mistakes that it is far from clear what Ryle took the central mistake in the dualistic position to be:

Sometimes he talks as it is speaking of the mind in the mechanistic-like terms (as in talk of mental causation). In other places, he seems to be worried by a kind of ‘double counting’ problem.[3]

Thus an intriguing question. How might we categorise ‘category mistakes’?

The idea of specifying (discovering? inventing?) ‘categories’ is at the heart of philosophy. It develops if not defines identity. If A is A, what exactly makes A not-B or different from B?

The English language gives us many different words to distinguish differences and similarities between objects and ideas: classes, sets, types, categories, forms, groups, kinds, sorts, orders, lists, classifications and so on.

The thematic idea is that all these words both include and exclude. It makes no practical sense to have a group or category or type embracing everything that exists or might exist. There must be criteria or rules that set up the terms for including and excluding.

There are many different ways for person X to make a mistake about or pertaining to a given category C. These include:

  1. X incorrectly thinks that item A is not a member of C, when in fact it is
  2. X does not know that A has some but not all of defining features that allow it to be accepted as a member of C
  3. X mistakenly thinks that categories C1 and C2 are really the same thing when they’re not, either by fact or by logic
  4. X thinks that A can be in C when that’s physically impossible
  5. X thinks that A can be in C when that’s logically impossible
  6. X thinks that different items have features in common to allow them to be put in the same category in practice, when in fact they don’t have such common features
  7. X thinks that merely by using the word A that A ‘exists’ and thereby can be categorised

Person X also might combine these mistakes in different ways for added confusion.

Magidor duly attempts to categorise what she sees as all these different ‘infelicities’:

  1. they are syntactically ill-formed
  2. they are meaningless
  3. they are meaningful but lacking in truth-value
  4. they are (despite being well formed, meaningful and having truth-value) pragmatically inappropriate.[4]

Nevertheless, our language (ie the words themselves), the delivery of the words (written or spoken; tone; emphasis) and context all variously combine to make it hard to pin down what, where and why exactly a mistake is or is not being made.

Take the following examples:

1001 + 1 = 1003

Monday is blue

Socrates is a man and a woman

The king of France is hairy

You can’t see Oxford University

This Jabberwocky is not as frumious as that Bandersnatch

He gazed at this girl like an ostrich goggling at a brass door-knob

Hairy French king Oxford University ostrich shock

Each of them make little if any sense if stripped of all context and presented starkly on a page. They make little if any sense for different reasons. They variously combine illogic, incongruity, impossibility, contradiction, lack of anything real to refer to, made-up words, mistaken identity, non-meaningfulness, and so on.

Yet in each case it’s not difficult to work out a language game or language/logic rule in which any of them would be acceptable or even in some sense meaningful, and certainly amusing or thought-provoking and so part of human life.

What, for example, of Ryle’s first category mistake version that in his view demolishes Cartesian mind-body dualism?

It does not seem altogether reasonable to argue that the baffled visitor to Oxford who cannot find the university ‘does not know how to wield the concept university’. That visitor visiting Hull University or Tufts University or Warsaw University or maybe most universities in the world would walk past a sign announcing the entrance to the university and know how to describe where s/he was.

Many (most?) universities were designed and built as such. They are primarily places. There are some (typically much older universities such as Oxford University) that emerged. They have very different statutes and organisational features. They might be said to be less of a place and more of an idea.

In short, the word university like so many words in English has a range of meanings of varying degrees of abstractness. It’s possible to go through life not knowing all of those meanings. It stretches the idea of a category mistake rather too far to say that anyone who does not know every meaning of a word is making such a mistake when using it.

Ryle specifically accuses Descartes of the category mistake that “represents the facts of mental life as if they belonged to one logical type or category (or range of types or categories), when they actually belong to another”. This suggests that mind-body substance dualism is at root a logic mistake. But what sort of logic mistake? And in what category do the ‘facts of mental life’ belong, logically or otherwise?

Is Ryle saying that Descartes errs first in language and then in logic/fact? Descartes (says Ryle) gets it all wrong by concluding that because he uses the word ‘mind’ therefore minds exist, and so by existing need to be explained in a way that makes sense when we look at other things that ‘exist’? That existence requires substance, and so (sic) minds and bodies both must be substances, albeit of radically different sorts?

Is Ryle asserting that Descartes’ confusion arises from the basic logical error of creating a pseudo-category (ie substance) that combines mind and body when they do not have (and cannot possibly have) in common what the category requires them to have in common?

Or is Ryle arguing that the mistake lies in ascribing physical properties such as cause-and-effect to mind and body in a way that on any meaning or use of those terms, including Descartes’ own meaning or use, is either necessarily contradictory or factually impossible, or both? The more the mind is different from the body, the more impossible it is for the mind in fact to act on the body and make it do things?

* * * * *

Descartes’ methods and conclusions reflected his basic goal expressed right at the start of the Meditations: to demonstrate by philosophical rather than theological argument “the fact (sic) that the human soul does not perish with the body, and that God exists”.

Once he started by taking it as given that there is both a human soul and a human body, itself arguably a banal category mistake or at best a dubious category assertion, all sorts of hard-to-fathom if elegantly argued practical and ontological conclusions had to follow.

Ryle briskly exchanges blows with Descartes’ core thinking, but without taking us much nearer to answering another Descartes question in the Meditations, a question expressed by him as science was starting to accelerate and that today seems ever-more prescient: how to tell the difference between machines and things that think or are conscious?

… I remember that, when looking from a window and saying I see men who pass in the street, I really do not see them, but infer that what I see is men, just as I say that I see wax. And yet what do I see from the window but hats and coats which may cover automatic machines?

These questions reveal the underlying problem in talking at all about what we call ‘the mind’. All we have to go on are what we call our ‘thoughts’ and what our senses take in about the world. Any attempt to put such non-tangible perceived phenomena into mere words comes loaded with metaphor, assumptions and the risk of self-deception.

Thus the expressions artificial intelligence or thinking machines. They appear in myriad different language games around the world every day.

But before we say a word about either of them, aren’t we already yielding to category mistakes? As a matter of fact or logic or definition or meaning or some combination thereof, surely intelligence can’t be artificial, and machines can’t think.

Does not either expression in question sneakily assume what it is trying to describe or define?

[1] The Philosophical Works of Descartes, trans. by Elizabeth S. Haldane (Cambridge University Press, 1911)

[2] Gilbert Ryle, The Concept of Mind (Hutchinson, 1949)

[3] Ofra Magidor, Category Mistakes (Oxford: Oxford University Press, 2013)

[4] Magidor, p.23 and passim