Varieties of Meaning: The 2002 Jean Nicod Lectures

"I chose it to represent another important strand of contemporary philosophy of mind, and that’s work on mental representation . Mental states – thoughts, perceptions, and so on – are ‘about’ things out in the world, and they can be true or false, accurate or inaccurate. For example, I was just thinking about my car, thinking that it is parked outside. Philosophers call this property of aboutness intentionality , and they say that what a mental state is about is its intentional content . Like consciousness, intentionality poses a problem for materialist theories. If mental states are brain states, how do they come to have intentional content? How can a brain state be about something, and how can it be true or false? Many materialists think the answer involves positing mental representations . We’re familiar with physical things that are representations of other things – words and pictures, for example. And the idea is that some brain states are representations, perhaps like sentences in a brain language (‘Mentalese’). Then the next question is how brain states can be representations. A lot of work in contemporary philosophy of mind has been devoted to this task of building a theory of mental representation. There are many books on this topic I could have chosen – by Fred Dretske, for example, or Jerry Fodor. But Ruth Millikan’s work on this is, in my view, some of the best and most profound, and this book, which is based on a series of lectures she gave in 2002, is a good introduction to her views. Yes, the problem is how mental representations come to mean, or signify, or stand for, things. If there’s a brain language, how do words and sentences of that language get their meaning? As the title indicates, Millikan thinks there are many varieties of meaning. To begin with, she argues that there is a natural form of meaning which is the foundation of it all. We say that dark clouds mean rain, that tracks on the ground mean that pheasants have been there, that geese flying south mean that winter is coming, and so on. There is a reliable connection, or mapping, between occurrences of the two things, which makes the first a sign of the second. You can get information about the second from the first. Millikan calls these natural signs . Other philosophers, including Paul Grice and Fred Dretske, have discussed natural meaning like this, but Millikan’s account of it improves on previous work in various ways, and I think it’s the best around. So this is one basic form of meaning, but it is limited. One thing is a sign of another – carries information about it – only if the other thing really is there. Clouds mean rain only if rain is actually coming. Tracks means pheasants only if they were made by pheasants, and so on. So natural signs, unlike our thoughts and perceptions, cannot be false, cannot misrepresent. Yes, they are what Millikan calls intentional signs . But normally they are natural signs too. Roughly speaking (Millikan’s account is very subtle and I’m cutting corners), an intentional sign is a sign that is used with the purpose of conveying some information to a recipient. Take a sentence of English, rather than a mental representation. (Sentences of human language are also intentional signs, as are animal calls.) Take ‘Rain is coming’. We say this with the purpose of alerting someone to the fact that rain is coming, and we can do this successfully only if rain is coming. (I can’t alert you to the fact that rain is coming if it’s not.) So if we succeed in our purpose, the sentence we produce will be a natural sign that rain is coming, just as dark clouds are. There’s a reliable connection between the two things. Now if we utter the sentence in error, when rain isn’t coming, then of course it won’t be a natural sign that rain is coming. However, it will still be an intentional sign that rain is coming in virtue of the fact that we used it with the purpose of signifying to someone that rain is coming. (Millikan argues that intentional signs are always designed for some recipient or consumer.) Roughly, then, an intentional sign of something is a sign whose purpose is to be a natural sign of it. No, but our brains do. Millikan has a thoroughly evolutionary approach to the mind. Evolution has built biological mechanisms to do certain things – to have certain purposes or functions. (This doesn’t mean that evolution had intentions and intelligence, just that the mechanisms were naturally selected for because they did these things, rather than because of other things they did.) And the idea is that the mind is composed of a vast array of systems designed to perform specific tasks – detecting features of the world, interpreting them, reacting to them, and selecting actions to perform. These systems pass information to each other using representations which are designed to serve as natural signs of certain things – and which are thus intentional signs of those things. In very general terms, then, the view is that mental representations derive their meaning from the purposes with which they are used. This sort of view is called a teleological theory of meaning. (‘Teleological’ comes from the Greek word ‘telos’, meaning purpose or end .) Oh yes. As I said, Millikan takes an evolutionary approach to the mind. She thinks that in order to understand how our minds represent things we need to look at the evolution of mental representation, and she devotes a whole section of the book to this, with lots of information about animal psychology and fascinating observations of animal behaviour. Millikan thinks that the basic kind of intentional signs are what she calls pushmi-pullyu signs, which simultaneously represent what is happening and how to react to it. An example is the rabbit-thump. When a rabbit thumps its hind foot, this signals to other rabbits both that danger is present and that they should take cover. The sign is both descriptive and directive, and if used successfully, it will be a natural sign both of what is happening now and of what will happen next. Millikan thinks that the bulk of mental representations are of this kind; they represent both what is happening and what response to make. This enables creatures to take advantage of opportunities for purposive action as they present themselves. But creatures whose minds have only pushmi-pullyu representations are limited in their abilities – they can’t think ahead, can’t check they have reached their goals, and can get trapped in behavioural loops. “This isn’t an easy book. You’ll have to work at it, and you may need to re-read the book several times. But it repays the effort” Millikan argues that more sophisticated behavioural control requires splitting off the descriptive and directive roles, so that the creature has separate representations of objects and of its goals, expressed in a common mental code, and she devotes two chapters of the book to exploring how this might have happened. Finally, she argues that even with these separate representations, non-human animals are still limited in what they can represent. They can only represent things that have practical significance for them – things relevant in some way to their needs. We, on the other hand, can represent things that have no practical value for us. We can think about distant times and places, and about things we’ll never need or encounter. Millikan describes us as collectors of ‘representational junk’ – though, of course, it’s this collecting of theoretical knowledge that enables us to do science and history and philosophy and so on. To represent this kind of theoretical information, Millikan argues, a new representational medium was needed with a certain kind of structure, and she thinks that this was provided by language. It is language that has enabled us to collect representational junk and do all the wonderful things we do with it. Yes. In fact, there’s another section of the book on what she calls ‘outer intentional signs’ (animal calls and linguistic signs). Millikan argues that linguistic signs emerge from natural signs and that they are normally read in exactly the same way as natural signs. We read the word ‘pheasant’ as we read pheasant tracks on the ground, as a natural sign of pheasants. We don’t need to think about what the speaker intended or had in mind. This view has some surprising consequences, which Millikan traces out. One of them is that we can directly perceive things through language. When we hear someone say ‘Johnny’s arrived’, we perceive Johnny just as if we were to hear his voice or see his face, Millikan argues. The idea is that the words are a natural sign of Johnny just as the sound of his voice or the pattern of light reflected from his face is. They are all just ways of picking up information about Johnny’s whereabouts. Of course, there is processing involved in getting from the sound of the words to a belief about Johnny, but Millikan argues that the processes involved are not fundamentally different from those involved in sense perception. It’s a controversial view, but it fits in with the wider views about perception and language that she develops. I should perhaps say that this isn’t an easy book. Millikan writes clearly, but the discussion is complex and subtle. You’ll have to work at it, especially if you’re new to the subject, and you may need to re-read the book several times. But it repays the effort. It’s packed full of insights, and you’ll come away with a much deeper understanding of how our minds latch onto the world."