:: Article

Category Mistakes

Richard Marshall interviews Ofra Magidor.

Ofra Magidor knows her days are not numbered but ochre underneath and that she’s the philosopher working out whether that is really true or not. She’s always thinking about category mistakes and about their two camps, about their relevance for linguistics and computer science, about what makes them odd, about why the idea that they’re syntactically ill-formed is wrong but more promising than some might think, about why they’re not meaningless, about why Wittgenstein is wrong on this, about the role of presuppositions, about pragmatism and semantics, about dynamic semantic theories, about truth-value gaps, about exciting projects in analytic philosophy and why women and non-whites are unrepresented in philosophy. Go sleep that pipe…

3:AM: What made you become a philosopher?

Ofra Magidor: In hindsight this was a very natural path for me to take, but it took me a fairly long time to realize this.

I have been intrigued by a variety of philosophical questions ever since I was a young child (I still remember discussing with other kids in kindergarten whether plants can feel, and at the age of nine worries about animal ethics led me to become a vegetarian – a commitment I still uphold). I also grew up in a relatively large family (I am one of four girls) and we spent hours over the dinner table debating any issue you can think of. My father (who is a professional mathematician) is an incredibly knowledgeable and broad-minded person. I love talking to him, and he introduced me to a lot of topics which are essentially philosophical.

Oddly, though, I hadn’t quite connected these interests with the academic discipline of philosophy. When I went to university, I knew I wanted to study mathematics and computer science, but I also thought I would receive a more well-rounded education if I took a humanities subject as well. I considered various options, but in the end I decided that philosophy would give me the most general tools for reading books and understanding new ideas – so I signed up for that.

For the first years of my undergraduate studies (at the Hebrew University of Jerusalem), I was completely gripped by my mathematics studies, with philosophy taking more of a back-seat role. (Worse – various bits of philosophy positively irritated me. I only realized later that I had to be quite invested in the topic to find it irritating…) But as my degree progressed I found that I was getting increasingly interested in philosophy. Discovering philosophy of language certainly played a role in that – two papers that did catch my attention in my first year of study were Frege’s ‘On Sense and Reference’ and Strawson’s ‘On Referring‘, and a series of advanced seminars led by Carl Posy exposed me to more recent work in the field. By the end of my degree, I decided I wanted to explore philosophy in a bit more depth. Since at that stage I was far from sure I wanted to continue with the subject long-term, I applied only to self-standing masters’ programmes and ended up signing up to the Oxford BPhil (which is a very intensive two-year master’s degree). The BPhil was a fantastic learning experience for me, and I especially benefited from working closely with Timothy Williamson (in particular, the way he combines clarity and precision with philosophical depth appealed to me very much). By the end of the BPhil I decided that I wanted to continue with philosophy and have never looked back since.

Two features I really like about the subject is first that you really get to think hard about which arguments are good or bad independently of whether you accept their conclusions and second that pretty much whatever topic you become interested in, you can connect it to philosophical work.

3:AM: So you’ve written about category mistakes. Can you first say what this phenomenon is? Is it widespread?

OM: Yes, one topic I have worked on is Category Mistakes. It’s hard to define what the phenomenon is abstractly, but it’s fairly easy to recognize once you’ve seen a few examples. It concerns sentences such as ‘The number two is blue’, ‘The theory of relativity is eating breakfast’, or ‘Green ideas sleep furiously’. These sentences, which are very odd (and odd in a distinctive sort of way), are what I call ‘category mistakes’.

The phenomenon is incredibly wide-spread. For a start, I haven’t been able to find a natural language that doesn’t contain category mistakes (it’s hard to imagine how there could be such a language – but I’m not just relying on this intuition. I asked speakers of a wide range of languages and all of them confirmed there are sentences that are odd in precisely this sort of way in their languages). Moreover, even within a language, category mistakes can arise in the context of very diverse grammatical constructions. For example, you can get them by applying an adjective to a noun (‘The number is blue’), but also via applying an adverb to a verb (‘sleep furiously’), or a prepositional phrase to an adjective (‘underneath the theory of relativity’).

3:AM: What have philosophers done with the issue before your treatment?

OM: In contemporary times, the peak interest in the phenomenon in philosophy occurred between the late 1930s and the early 1980s. Putting things very crudely, there were two camps. The first, took the phenomenon very seriously, and argued that category mistakes are meaningless or at the very least truth-valueless. Many people in this camp also followed the lead of Ryle in thinking that taking category mistakes to be meaningless had significant implications to metaphysics (one line of thought here is that if category mistakes are meaningless then if the statement of some philosophical issue is a category mistake, then there is no point in pursuing that issue). The other camp followed the lead of Prior and Quine in maintaining that category mistakes are perfectly ordinary, meaningful, and truth-valued sentences. Philosophers in this camp were generally very dismissive of the phenomenon.

What was largely missing from the literature was a treatment which on the one hand accepts that category mistakes are meaningful and truth-valued, but on the other hand recognizes that there is a substantial phenomenon here in need of an account – which is the sort of position I defend.

3:AM: You say it’s important for linguistics, computer science – how so?

OM: In the case of linguistics, it is fairly obvious why category mistakes are important: one of the central tasks of linguistics explaining why some sentences are fine and others are infelicitous. In fact, category mistakes are a particularly interesting case, because a plausible argument can be made for explaining their oddness in terms of each of syntax, semantics, and pragmatics – so this is a good phenomenon to explore for anyone who is interested in the distinction between these three realms of language. This is probably why in the late 1960s category mistakes played a key role in one of the central disputes in the foundations of linguistics – that between interpretative semanticists (who claimed that syntax is autonomous of semantics) and generative semanticists (who rejected the sharp divide between these two realms).

I should also note there was a period in the 1960s when there was quite a lot of discussion of category mistakes happening in a parallel in linguistics and in philosophy, but there was practically no interaction at all between the two fields on this topic (they even used different terms – in linguistics authors usually refer to category mistakes as ‘selectional violations’). One thing I tried to do in the book was to bring together these two parallel debates. I’d like to think that these days there is much more co-operation between linguists and philosophers of language so this kind of divide is less likely to happen.

Moving to computer science: one straightforward way in which category mistakes are relevant is because of the field of computational linguistics. Suppose for example that you have an automatic translator which is given the sentence ‘John hit the ball’. If the translator looks up the word ‘ball’ in a dictionary, it will encounter (at least) two meanings: a spherical object that is used in games, and a formal gathering for dancing. It is obvious that the most natural interpretation of the sentence used the former meaning, and one way to see that is to note that if ‘ball’ were interpreted in the ‘dance’ sense, the sentence would be a category mistake. So being able to recognize category mistakes can help the automatic translator reach the correct interpretation.

But there is also a more general way in which the topic is relevant to computer science: computer programs use variables of various types which are assigned values – and it is very common to encounter cases where the value is of the wrong type for the variable. So there is an issue about how the program is going to deal with this kind of type mismatch which is in some ways parallel to the question of how natural languages deal with category mistakes.

3:AM: Your question is what makes category mistake sentences odd rather than trying to work out what makes them distinctive. Why that focus? Are you backlashing against the traditional analytic approach?

OM: Yes, I focus a lot more on the question of explaining why category mistakes are odd than working out what makes them distinctive. This is partially because I don’t have a very good answer to the latter question (and I am fairly sceptical that a fully satisfactory answer can be found), and partially because I think that the first question is interesting enough in its own right. In this respect I’m following a general trend in contemporary philosophy which moves away from the traditional project of analysing concepts, and instead attempts to say some informative and interesting things about the concept without analysing it.

It’s worth saying, though, that as opposed to some other concepts in philosophy (e.g. the concept of knowledge or of possible worlds) in the particular case of category mistakes there was never really a tradition of analysis. Pretty much everything that was written about category mistakes fell under the project of trying to explain why they were odd or of connecting the concept to other issues (e.g. in metaphysics), rather than to give necessary and sufficient conditions for what makes something a category mistake. A nice feature of this debate is that there is a lot of disagreement about how to account for category mistakes, despite there being surprisingly little disagreement about which sentences count as examples of the phenomenon.

3:AM: What’s the syntactic approach to category mistakes and what does it offer – and what does it get wrong?

OM: The syntactic approach maintains that category mistakes are syntactically ill-formed, or ungrammatical. I suspect most philosophers these days think this view is obviously wrong, but I actually think it’s a bit more promising than it appears at first. Interestingly, while many people remember that Chomsky offered the category mistakes ‘Colourless green ideas sleep furiously’ as an example of a sentence that is grammatical but meaningless, fewer people realise that he later defended the view that it is ungrammatical. One interesting argument in support of this syntactic approach (this is part of what motivated Chomsky) is that paradigmatic category mistakes seem very close to other sentences which are more plausible candidates for being ungrammatical: for example, who/which confusions (‘The boy which is on the table is tall’), or inappropriate uses of ‘that’-clauses (‘John ate that the world is round’). Nevertheless, I ultimately think the syntactic approach fails. To see the full argument you’ll obviously need to look at the book, but here’s one central consideration: syntax is by and large context invariant, but whether or not a sentence is a category mistake often depends on the context of utterance. If I say to you ‘The think we were just talking about is blue’ it makes a big difference if we were just talking about my new sofa or about the theory of relativity.

3:AM: ‘Green dreams sleep furiously’ may strike people as being meaningless. Would they be wrong? Does metaphor help to establish your point that category mistakes aren’t meaningless?

OM: I see why it’s tempting to say that category mistakes are meaningless, but I think this claim is wrong. One argument for why category mistakes aren’t meaningless concerns metaphors. Many metaphors are sentences which, if taken literally, would be category mistakes (think for example of ‘This poem is pregnant’ or ‘She cut the silence with a knife’). These metaphors have some sort of metaphorical meaning or at least a communicative purpose. This doesn’t yet show that they have a literal meaning, but I argue that any plausible theory of metaphors ultimately has to accept that they are literally meaningful (either because, as Davidson argued, metaphors have only a literal meaning or because, as I argue, their metaphorical meaning depends on the literal meaning in a way that requires the metaphor as a whole to be literally meaningful).

Note that one consequence of my argument is that it is not always fully transparent to speakers whether sentences are meaningful or not (reasonable and competent speakers can be mistaken about this question).

3:AM: Does this approach of yours show that Wittgenstein wrong in condemning so many discourses to meaninglessness?

OM: Yes, I think it does. To be a bit more precise, my view doesn’t completely rule out the view that some discourses are meaningless: I do think that sentences which contain meaningless words are themselves meaningless, and it’s not out of the question that some words we use (especially in highly theoretical contexts) are meaningless. But there are also many philosophical questions which some have thought to be meaningless, but which can be phrased using clearly meaningful words. Consider for example the question whether the number one is identical to the singleton set of the empty set, whether colours exist, or whether I was once a foetus. Given my view of category mistakes, one cannot say that these questions are meaningless. Actually, if one accepts my view that category mistakes are not only meaningful but truth-valued, it follows that these questions have a correct answer (true or false), so even though these questions might seem very abstract and intractable, one cannot simply dismiss them.

3:AM: Why are presuppositions – background information – important?

OM: Presuppositions, as I’m using the term, are not quite background information but rather information that is expected to be taken for granted by participants in the conversation when certain sentences are uttered. For example, when you say ‘It was Jill who murdered Jack’, you normally assume that it’s already accepted in the conversation that Jack was murdered. If it isn’t already accepted, your utterance would seem very odd and the standard theory says it suffers from a presupposition failure.

I argue that the oddness of category mistakes is an instance of the same phenomenon: when you utter a sentence of the form ‘X is blue’, you assume that it’s taken for granted in the conversation that X is coloured. But except in very special cases, it certainly is not taken for granted in the conversation that the number two is coloured, so an utterance of this sentence would suffer from a presupposition failure and would thus be odd.

3:AM: Why label this as a pragmatist approach rather than another semantic approach to category mistakes?

OM: There is a disagreement between scholars on how to draw the distinction between semantics and pragmatics. (Some of dispute here is substantive, and some it more terminological.) I’m following one prominent tradition which classifies as semantic those linguistic features which contribute to the truth-conditional content of an utterance. One consequence of classifying things this way is that a feature can count as pragmatic even if it is part of the conventional meaning of a sentence. Consider for example Grice’s concept of Conventional Implicature – Grice argued that when you say ‘She is poor but happy’, the content of your sentence is just that she is poor and happy, and this is all we need to consider in order to determine whether the sentence is true or false. Still, it’s part of the conventional meaning of the word ‘but’ that using this sentence implies that there is some sort of tension between being poor and happy.

The reason that I label my approach to category mistakes pragmatic is that, according to my theory, category mistakes involve presupposition failures but these do not affect the truth-conditions of the sentence (the sentence is true or false, independently of whether it suffers from a presupposition failure). Now there is a further question whether the presuppositions that each sentence generates is somehow written into the conventional meaning of the sentence or can be determined by more general conversational principles. My money is on (a version of) the former option, but actually for my purposes it doesn’t matter which of these is correct. Even if presuppositions are part of the conventional meaning, they would still count as pragmatic on the above classification.

3:AM: You don’t think much of dynamic semantic theories that allow for true and false sentences with presupposition failures, and you also reject the idea that category mistakes are meaningful but without truth a value? Are the reasons for rejecting these connected?

OM: Dynamic semantics theories are just one instance of the kind of theory that maintains that sentences which suffer from presupposition failure are neither true nor false. If we combine this view of presupposition failures with a presuppositional account of category mistakes, we get one version of the view that category mistakes are meaningful but truth-valueless. I do reject all theories that fall under the latter category. Very roughly, my reason is that I think the only way sentences can be neither true nor false is by failing to express a proposition, and I argue that category mistakes are not good candidates for being such sentences.

3:AM: Do you allow for any truth value gaps?

OM: I definitely accept one kind of truth-value gap: utterances which fail to express a proposition are neither true nor false. For example, if I utter ‘That is green’ but fail to refer to anything with ‘that’, I haven’t expressed a proposition and my utterance is consequently neither true nor false. I think it is much harder to accept that propositions can be neither true nor false (or even neither true nor false relative to another possible world).

I don’t want to be completely definitive here: perhaps really hard problems such as the liar paradox will ultimately force us to accept propositions with truth-value gaps (at least in the minimal sense of neither accepting nor rejecting that all propositions are true or false). But in linguistics, theorists tend to be very casual about appealing to ‘gappy propositions’, without noting that these have very serious implications for our theories of truth. I certainly don’t think the category mistakes warrant this kind of radical consequence.

3:AM: Why do you prefer the pragmatist approach to the rivals? Is it your settled view that category mistake sentences are straightforward descriptions of the world that it is up to the world to settle?

OM: Ha – you’ll really need to read the whole book to see why I prefer the pragmatic approach to its rivals!

Regarding the second question: I do think that the content expressed by a category mistake is just a straightforward statement which is up to the world to settle. (In another sense, though, category mistakes are not straightforward – they are pragmatically inappropriate because they suffer from presupposition failures.)

Some of my opponents have objected that it is hard to imagine how the world could possibly settle whether two is green, or that if we insist on assigning a truth-value to ‘Two is green’ it’s hard to see this value as being anything but arbitrary. But even if we put aside my arguments and focus on our pre-theoretic intuitions, I find these worries quite surprising. After all, if God came to you and told you that ‘Two is green’ does have a truth-value and you have to bet which truth-value that is, I’m sure you would opt for ‘false’. (This is a much easier question than what you would bet on if God asked you the parallel question about the continuum hypothesis!). Once you think of things this way, it doesn’t seem so hard to accept that the sentence is simply false.

3:AM: Philosophy has taken a lot of stick recently – physicists say there’s nothing it can add to what they’re doing, philosophers say it is just empty ideas or unenlightening, and its undoubtedly the case that there’s something wrong in the academy representation and treatment of women philosophers, as well as non-white ones. So how would you push back against the critics – and what could be done to sort out the problems?

OM: You raise two very different issues here. The first one concerns the criticisms about the content of philosophy. Obviously, to respond to these properly one would need to look at the details of each complaint, but I’m generally sceptical about these concerns. The last two decades have actually seen some extremely exciting work in philosophy (particularly so in areas which have been the focus of some attacks, such as analytic metaphysics). When one discusses such abstract topics, it’s easy to lose nerve and wonder whether the questions asked are even intelligible, or whether we have any hope of answering them. I am not ruling out at the outset that some questions we are asking will turn out to be not very good ones – but I don’t think we can decide that in advance of our enquiry. We have to try to work through them patiently and carefully and see where they lead us.

The second issue you raise is about the underrepresentation and mistreatment of women and other minorities in the profession. This is an issue which I think we should take very seriously and address with some urgency. The underrepresentation of non-white philosophers is probably a worse problem than the underrepresentation of women, because there we don’t yet have anything approaching a critical mass.

I’m afraid I don’t have a simple solution to these problems – they will probably take a very wide range of measures to sort out. But we shouldn’t lose heart either. There are a lot of small things that each of us can do to improve the situation. One thing I think we can all can work on (myself included, of course!) is to try being more supportive and less aggressive towards other philosophers. I want to stress that the reason I take this point to be connected to the issue about minorities is not that women (or for that matter other minorities) are by their nature less resilient to aggressive behaviour. It’s rather that when you’re a member of a minority you are already likely to feel more vulnerable in a group situation, and if members of the majority are also aggressive that deepens the effects of this vulnerability. I all for having rigorous and critical philosophical discussions, but I see no reason to think that treating others with decency and respect should come at the expense of having such discussions (a good place to start is to try to think of good role models: which philosophers do you know who are on the one hand sharp critics, but on the other hand voice their views in a friendly and constructive manner?). I also think particular initiatives such as the Gendered Conference Campaign or even the recently proposed Bechdel Test for Philosophy can do quite a lot to improve the situation. (The point of these, of course, isn’t to include female authors in your conference or paper just for the sake of it. Rather, it’s often the case that when you think hard about whether there are any female philosophers you could have included you’ll find that you have overlooked some excellent potential contributors.)

3:AM: And finally for the philosophically curious here at 3:AM, can you recommend five books that will take us further into your philosophical world?

OM: Since the interview focused on my work on category mistakes, I thought I would suggest some books which relate to some of the other topics I’ve worked on. So here goes:

1. Aristotle’s Physics: Of all the figures in the history of philosophy, Aristotle really stands out. I spent a fair amount of time as a graduate student reading (and writing about) Aristotle, and was especially drawn to The Physics. Unfortunately, I found that keeping up this interest required more resources than I currently have, but I do hope to return to “The Philosopher” one day!

2. Timothy Williamson, Vagueness: the problem of vagueness is, to me, one of the deepest problems in the philosophy of language and there is no better place to read about it than Williamson’s book.

3. Kit Fine, Reasoning with Arbitrary Objects: This is the only book-length discussion of an issue which (as opposed to the problem of vagueness) received far too little attention in philosophy: how we should understand statements such as ‘Let n be an arbitrary number’, and their use in proofs. I think this problem also runs very deep (in fact, I think it’s related to many other problems in the philosophy of language, including possibly to the problem of vagueness). It’s a terrific book, but be warned that it’s by no means an easy read…

4. Theodore Sider, Four-Dimensionalism: Sider’s book is a great example of how one can make huge progress in philosophy by taking a fairly vague debate, and getting much clearer about what the different positions and the arguments for and against them are. I think that there are still some fundamental confusions that need to be cleared in this area, but Sider’s book is a cornerstone of the discussion.

5. Barbara Partee and Paul Portner, Formal Semantics: the essential readings: This one is a bit of a cheat because it’s a collection of papers, but what a collection! Two papers in this collection which have been particularly central to my own work are Stalnaker’sAssertion’, and Heim’s ‘On the projection problem for presupposition’. But it’s hard to imagine practically any discussion in contemporary semantics or philosophical linguistics which does not owe a huge amount to the works in this collection. Two additional things to note: this collection is a good reminder of the tremendously important role that women (in this case Heim, Kratzer, and Partee) have played in these fields, and it also contains some great examples of the fruitfulness of interaction between philosophers of language and linguists.


ABOUT THE INTERVIEWER
Richard Marshall is still biding his time.

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First published in 3:AM Magazine: Friday, October 17th, 2014.