In the following I try and explain where I think the difficulties in the idea of a category mistake (which are more to do with the notion of a category than the notion of a mistake) arise. In The Concept of Mind, Ryle took himself to be pointing to a general way in which reasoning can go wrong, but the other examples he gives (like the confusion over Oxford University and its colleges, and over the units of an army and the army itself) are really good illustrations of what is at stake in his approach to the mind-body problem. They seem more trivial, and are more like problems about the relationship between parts and wholes than they are like the issue of the allegedly mistaken Cartesian view of mind-body relations.
Just about any misidentification or misdescription can of course be said, in a trivial sense, to be a category mistake ('not a dog, but a fox'), but this doesn't reflect the main usage to which either Ryle or the other examples put the phrase. The difference at stake can perhaps be said to be that between the categorial (sic, with no 'c') and the merely categorical. Ryle himself in fact distinguished 'theoretically interesting' and 'radical' category mistakes from other kinds, and perhaps this difference is implicit in his doing so.
Anyhow, the difference indicated is why I wouldn't really happy, for example, with the suggestion that 'the only reason one could complain about this is if one denied that the properties which things have (and thus the categories under which they fall) can be exhausted in our knowledge ofthem. But this seems like an extremely implausible skepticism.' In the case of common or garden miscategorisations, let's assume we can
indeed exhaustively tell what properties things have; we can reliably know blue from green, dogs from foxes, etc. Surely, however, the picture changes when we are required to tell historical thinking from moral reasoning, or scientific argument from religious belief, or from dramatic speech.
After all, it is by no means obvious that 'science' (for example), is a 'thing', and if it is, it is certainly not a 'thing' like an Oxford College or a military unit; it is not an object of sense-perception at all, and presumably therefore cannot have 'properties' in the same way either. Whether we choose to call science a mode of experience, a form of thought, or whatever, its properties or distinguishing features remain non-sensible.
So, if it is not a misnomer to describe a confusion between, say, science and religion or historical and moral thought as a confusion between categories, the notion of a 'category' does, when used in this sense, become problematic. We may have established that 'science' cannot be the same *kind* of category as a biological genus, or a colour pallet, but quite what kind of a category it is remains somewhat obscure. Ryle actually uses 'logical type' as a synonym for 'category', but the precise meaning of the adjective 'logical' is not obvious. That 'Science is a logical type' = 'science is a category' still leaves plenty of work to be done.
One possible answer to the problem is that 'science' is a particular kind of discourse, and it has certainly been suggested that the non-trivial sense of the term 'category mistake' being discussed here arose in association with the so-called linguistic turn in philosophy that Wittgenstein's Philosophical Investigations did so much to help bring about. Category mistakes, on this view, are semantic confusions des genres, muddlings up of different vocabularies, and so on. There's a lot to be said in favour of this view, but its not all there is to the matter.
This is because the problem exists 'avant la lettre'. Indeed, Ryle is effectively accusing Descartes himself of a category mistake, meaning that such errors were as possible in the
seventeenth century as they are now. Whether this is mere anachronism or a genuinely illuminating approach to the history of philosophy is perhaps not uncontroversial, but provisionally, let us say that Ryle is (historically) justified in taking this position. From notes elsewhere on this site it should appear that the problem in its modern form dates back at least to Kant, and his argument that there are a priori conditions for understanding, there is no obvious difficulty with extending it further back.
One might, indeed, even push the history of the problem all the way back to Aristotle, whose delineation of the various fields of thought really draws up the map of knowledge within which (very broadly) we are all still working (though the contours of individual features have, at least in some cases, changed out of all recognition since his time). In one of the examples quoted, Bernard Williams certainly seems to think it makes sense to talk in terms of category mistakes in Greek philosophy.
Although, then, it is true in one sense that the problem of telling a scientific theory from a religious belief is like telling that of telling a dog from a cat, in that it simply a problem of what set something belongs to, in another sense, it seems to be a qualitatively different issue, and describing both in terms of knowledge of things and their properties is unhelpful insofar as it obscures this difference.
Our own era is characterized by the increasing recognition that there is an irreducible but small and determinate plurality of forms or kinds of understanding, each of which has its unique conditions attached, and the challenge is to specify them while remaining alert to their historicity. Hence, ultimately, the interest of the idea of a category mistake, and the sense of its difficulties.
Hi, Luke - I think I have a better sense now of what you find problematic in the notion of a category mistake: category mistakes are logical confusions that are clearly committed in certain easy cases. But the differences between science and religion, the relationships between the mind and the body, etc. are extremely complex and so these are "qualitatively different issues."
I think you're right about this. But I wouldn't, as you seem to, put the difference in the kinds of things themselves. The difference seems to be rather with the type of discourse in which the category mistake charge is made. In the Oxford case, the person who asks to see Oxford after they have taken a tour of the campus has the wrong idea about what a university is. It isn't something which one can see, a material thing. Oxford is, as Ryle says, "the way in which all that he has already seen is organized." We know what a university is (or at least, this issue is not up for debate at the present time), and so we are in a position to say to this person that they are making a category mistake.
When the task at hand is to determine what a thing is, however, and when neither party can claim to have the decisive answer to this question, then to say that one has committed a category mistake can be nothing more than an accusation which some will buy and others won't. Perhaps Descartes did commit a category mistake in saying that the mind was immaterial. But perhaps not. For the committed Cartesian, Ryle is simply begging the question against Descartes.
Put another way, we can say that when the question explicitly concerns the nature of a thing, and thus the categories under which it falls, we put the cart before the horse if we say that one has committed a category mistake because it is a thing's nature which is precisely at issue.
If this is the right analysis, the notion of a category mistake has a limited theoretical value. But then this should not surprise us. It's by now a well-worn saying that "One man's modus ponens is another man's modus tollens." This is yet another example of how logic is merely formal.
Anyway, it's interesting stuff. I'll be looking forward to see where else you go with it!