These squiggles have a meaning. So do spoken words, road signs, mathematical equations and signal flags. Meaning is something with which we’re intimately familiar – so familiar that, for the most part, we barely register or think about it at all. And yet, once we do begin to reflect on meaning, it can quickly begin to seem bizarre and even magical. How can a few marks on a sheet of paper reach out across time to refer to a person long dead? How can a mere sound in the air instantaneously pick out a galaxy light-years away? What gives words these extraordinary powers? The answer, of course, is that we do. But how?

A slogan often associated with the later philosophy of Ludwig Wittgenstein (1889-1951) is ‘meaning is use’. Here’s what Wittgenstein actually says:

For a large class of cases of the employment of the word ‘meaning’ – though not for all – this word can be explained in this way: the meaning of a word is its use in the language.

In order to appreciate the philosophical significance of this remark, let’s begin by looking at one of the key things that Wittgenstein is warning us against.

Suppose I say: ‘It’s hot today.’ So does a parrot. Saying the words is a process; for example, it can be done quickly or slowly.

However, unlike the parrot, I don’t just say something: I mean something. This might suggest that, when it comes to my use of language, two processes take place. But where does this second process – that of meaning something – occur? Unlike saying something, it doesn’t appear to be publicly observable. And so it’s tempting to conclude that, while it might say something, the parrot doesn’t mean something because it fails to engage in the relevant private process.

The thought that meaning is a kind of private accompaniment to the public use of language is something that Wittgenstein was particularly concerned to warn against. It’s a thought that can be found in the work of many philosophers. Take John Locke (1632-1704), for example. Locke thought that most words obtain their meaning by being correlated with certain private mental items that he calls Ideas.

On Locke’s view, the mind is like a container. At birth, the container is empty, but our senses soon begin to furnish it with Ideas. We acquire simple Ideas, such as of the colour red. Simple Ideas constitute the basic building blocks of thought. We can then form more complex ideas by combining our simple ideas together. For example, I can combine my idea of white, round, solid and so on to form the idea of a snowball.

On Locke’s view, words obtain their meaning by standing for these private mental items:

words in their primary or immediate signification stand for nothing but the ideas in the mind of him that uses them …

So, on Locke’s view, the explanation for why I, unlike the parrot, don’t just say something, I mean something is that I’ve learnt to correlate those public words with the relevant private items. So, again, we’re supposing that meaning is a private mental accompaniment to the public use of public language.

How, according to Locke, am I able to understand a word and apply it correctly? Suppose someone asks me to pick a red flower from a vase of coloured blooms. How am I to know to which flowers ‘red’ applies? On Locke’s view, on hearing ‘red’, I rummage through my memory – which Locke thinks of as a ‘storehouse of our Ideas’ – to find the Idea I previously learnt was correlated with ‘red’. This retrieved Idea then provides me with a sample of ‘red’ – a mental image – with which I can compare the flowers in front of me until I get a match.

In short: when we start to think about meaning and understanding, we’re easily drawn towards a picture of them as private accompaniments to our public use of language. It’s a picture that Wittgenstein rejects. On his view, meaning resides entirely in the public use we make of language, not in any such private accompaniments.

Let’s look at two of Wittgenstein’s arguments against the view that meaning is a private accompaniment.

First, he provides some linguistic therapy ­– pointing out that we made a mistake when we concluded that meaning must be a parallel process:

But what tempts us to think of the meaning of what we say as a process essentially of the kind which we have described is the analogy between the forms of expression:
    ‘to say something’
    ‘to mean something’,
which seem to refer to two parallel processes.

The superficial similarity between ‘to say something’ and ‘to mean something’ led us to conclude that, because saying something is a process, so meaning must be a process too. Only, because it’s not a public process, it must be a private mental process.

But, Wittgenstein reminds us, if we look at how ‘to mean something’ is used, we discover that it’s not a process at all. Saying something is a process. That’s confirmed by the fact that it makes sense to talk about doing it more quickly or slowly, or interrupting it. However, we would be baffled by talk of someone ‘meaning something faster than they say it’, or who ‘stopped meaning it halfway through’ – which we wouldn’t be if it were talking about a parallel process. Pointing this out is an exercise in revealing what Wittgenstein calls the ‘depth grammar’ of ‘to mean something’. ‘To mean something’ might look superficially like ‘to say something’, and so might also seem to refer to a process. But when we examine more closely how ‘to mean something’ is used, it turns out the appearance is deceptive:

What immediately impresses itself upon us about the use of a word is the way it is used in the construction of the sentence, the part of its use – one might say – that can be taken in by the ear. – And now compare the depth grammar, say of the word ‘to mean’, with what its surface grammar would lead us to suspect. No wonder we find it difficult to know our way about.

But if meaning isn’t a process, we don’t then have to suppose that, as we don’t observe it taking place alongside the saying, it must be a private mental process.

Wittgenstein also points out that positing an internal ‘looking up’ process to explain how we’re able to understand and apply words correctly involves a circularity. If I’m able to pick a red flower only by pulling out my internal mental sample of red and comparing the flowers with it, then how am I able to identify the correct mental sample? At this point, we’re presupposing the very ability we’re trying to explain – the ability to pick out ‘red’ things.

Of course, you might insist that I can just immediately identify which mental sample is red without comparing it to anything at all. But then why not say the same thing about the flower? In fact, isn’t that exactly what happens – you pick out the red flower without comparing it to anything at all? Introducing a private inner object to explain how you’re able to identify the outer object as ‘red’ is superfluous.

Perhaps you’re unconvinced. After all, we do use colour samples to tell us what words mean. I might use a decorator’s colour chart to remind me what ‘puce’ means, for example. But in that case, the colour sample and the word are objectively correlated – perhaps physically taped together. So they provide me with something independent I can file away for future reference. The problem with the suggestion that I can ‘look up’ the meaning of ‘red’ by rummaging through my storehouse of Ideas to find the relevant private mental sample is that such samples aren’t objective. Just like a pain, a mental image of red can’t exist unexperienced. So, when later I want to know what ‘red’ means, I need already to know what ‘red’ means in order to conjure up the correct mental image. Compare trying to identify which colour sample is ‘puce’ when the words and the colour samples have not been physically attached to each other but just thrown willy-nilly into a drawer. I need already to know what ‘puce’ means to identify the correct sample. Similarly, the inner ‘looking up’ process that supposedly explains how I’m able to pick a ‘red’ flower just presupposes the ability to pick or conjure up the ‘red’ mental sample.

The truth, Wittgenstein reminds us, is that usually, when we’re asked to pick a red flower, we don’t engage in any such inner comparison:

We go, look about us, walk up to a flower and pick it, without comparing it to anything. To see that the process of obeying the order can be of this kind, consider the order ‘imagine a red patch’. You are not tempted in this case to think that before obeying you must have imagined a red patch to serve as a pattern for the red patch which you were ordered to imagine.

In short, Wittgenstein supposes that, as a result of confusion and inattention to differences in use, we end up supposing that language consists in two parallel activities – one public, the other private:

We are tempted to think that the action of language consists of two parts; an inorganic part, the handling of signs, and an organic part, which we may call understanding these signs, meaning them, interpreting them, thinking. These latter activities seem to take place in a queer kind of medium, the mind; and the mechanism of the mind, the nature of which, it seems, we don’t quite understand, can bring about effects which no material mechanism could.

It’s this picture of meaning and understanding as private accompaniments to the public use of language that Wittgenstein is particularly concerned to reject.

It’s worth stressing, incidentally, that Wittgenstein doesn’t deny that there’s stuff happening in our brains that causally underpins our public use of language. Of course there is. A scientific investigation might even make those physical goings-on public. What Wittgenstein rejects is the view that the essence of meaning and understanding resides in some necessarily private domain.

You might be feeling dissatisfied. If Wittgenstein rejects Locke’s theory of meaning, what does he offer in its place?

On Wittgenstein’s view, we don’t need a philosophical ‘theory’ of meaning and understanding – or indeed of anything. ‘Meaning is use’ is intended, not to encapsulate a philosophical theory, but rather to remind us of what was always right before our noses. To return to our original question: what’s the difference between me and the parrot that explains why I mean something when I say ‘It’s hot today’ while the parrot does not? On Wittgenstein’s view, the relevant differences reside, not in any private accompaniments to my public saying, but in what we’re able publicly to do. I possess a wide range of abilities that manifest my grasp of what I mean. For example, I can explain what must be the case for the sentence to be true. I can explain what the word ‘hot’ means by pointing to examples or by using other words. And I can successfully combine the words ‘hot’ and ‘today’ in other sentences. A parrot can do none of these things.

The revolution in thinking about meaning to be found in Wittgenstein’s later work lies in this shift in focus from private inner accompaniments to what’s publicly observable. Meaning and understanding reside, not in some mysterious private realm, but entirely in the public domain. On Wittgenstein’s view, to grasp the meaning of a word is not to have associated it with some private inner object but, roughly, to know how it’s used.

When it comes to mind and meaning, Wittgenstein offers us, not philosophical theories, but therapy, so that we don’t end up tempted down the rabbit hole of introducing bizarre and mysterious private realms.