Private language

A private language, in Wittgenstein's sense, would be a language whose words refer to what only the speaker can know: his own immediate sensations, so that nobody else could possibly understand it (Philosophical Investigations §243). Wittgenstein's private language argument, mainly in §243-315, tries to show that such a language is not really possible, and that the picture behind it, of each of us naming our sensations by looking inward, is confused.

This is not about secret codes or a diary in shorthand. Those could in principle be cracked. The target is a language that is private by its very nature.

What the animation shows

In the animation above four people each hold a box. Each looks only into his own box and says "beetle". Then the lids lift, for you alone: one box contains a beetle, another something quite different, a third is empty, and in the fourth the thing keeps changing. Yet the word "beetle" goes on working perfectly well between them. They can talk about their beetles, compare notes, agree and disagree. Whatever is in the box plays no part in that.

This is Wittgenstein's beetle in a box (§293). Suppose, he says, everyone had a box with something in it called a "beetle", and nobody could look into anyone else's box. If the word still had a use, it would not be the name of a thing:

Das Ding in der Schachtel gehört überhaupt nicht zum Sprachspiel; auch nicht einmal als ein Etwas: denn die Schachtel könnte auch leer sein.

The thing in the box has no place in the language game at all, not even as a something: for the box might even be empty.

Philosophical Investigations §293

The lesson is aimed at a familiar thought: "I only know what pain is from my own case." If words for sensations got their meaning from a private object that only I can inspect, that object would "drop out" of the shared language as irrelevant. Since our word "pain" plainly does work, its meaning cannot come from a private inner sample.

The diary and the sign "S"

The animation ends with a diary. In §258 Wittgenstein imagines keeping a record of a recurring sensation. I associate it with a sign and write that sign in a calendar every day I have the sensation. (In the German original the sign is "E", for Empfindung, sensation; English translations use "S".) I cannot define the sign for anyone else, so I give myself a kind of inner pointing definition: I concentrate on the sensation and write the sign.

But what will make my future use correct? Only my impression that this is the same sensation again. And that, Wittgenstein says, is no check at all:

Man möchte hier sagen: richtig ist, was immer mir als richtig erscheinen wird. Und das heißt nur, daß hier von ‚richtig‘ nicht geredet werden kann.

One would like to say here: whatever is going to seem right to me is right. And that only means that here we cannot talk about "right".

Philosophical Investigations §258

It is like checking the time in your memory of a timetable: it only helps if the memory can itself be checked against something. This is where the private language argument meets rule-following. A few pages earlier Wittgenstein wrote that thinking one is following a rule is not following a rule, and that one therefore cannot follow a rule "privately" (§202).

How do sensation words work, then?

Wittgenstein offers a suggestion, not a theory (§244). A child hurts himself and cries; adults talk to him and teach him exclamations and later sentences. The words replace the natural expression of pain. Saying "it hurts" is a new, learned kind of pain behaviour, not a report about a private object. That fits the broader idea that meaning lies in use: the word "pain" belongs to a shared practice of crying, comforting, asking and treating.

Is Wittgenstein denying that we feel anything?

No, and he says so explicitly. His imagined critic asks whether he is a behaviourist in disguise, and whether he thinks everything except human behaviour is a fiction (§307). Wittgenstein answers that the sensation is not a nothing:

Sie ist kein Etwas, aber auch nicht ein Nichts!

It is not a something, but not a nothing either!

Philosophical Investigations §304

What he rejects is a particular grammar: the model of "object and name" applied to the inner life. Pain is real. What is confused is the idea that the word "pain" means what it means by labelling a private item.

How the argument has been read

Few passages have produced more disagreement. In a 1954 symposium A.J. Ayer argued that even a lifelong Robinson Crusoe could name his sensations and remember them; Rush Rhees replied that naming only makes sense within a shared language. The same year Norman Malcolm wrote an influential review of the Investigations that set the agenda for decades.

In 1982 Saul Kripke argued that the real argument comes before §243, in the remarks on rules, and that the diary passage merely applies a general conclusion about meaning. Many commentators reject this, since it makes §256-271 look superfluous. Others read Wittgenstein "therapeutically": he is not proving a thesis that private languages are impossible, but showing that the very idea, once you try to spell it out, falls apart into nonsense. The Stanford Encyclopedia entry on private language sets out these positions carefully, and the main entry on Wittgenstein places the argument in his later philosophy.

Why it still matters

The argument is a challenge to a picture of the mind going back to Descartes, in which each of us is directly acquainted with an inner theatre that others can only guess at. If Wittgenstein is right, our words for feelings are public from the start, learned in shared situations, tied to expression and response.

That also changes an everyday sentence like "you can't know how I feel". In one sense it is true: you have the toothache, not me. But the words in which you tell me about it are ours, not yours alone, and that is exactly why I can understand you. You can read §243-315 in German at the Ludwig Wittgenstein Project.