The Private Language Argument

The private diarist

Imagine you have an inner sensation you want to track. Each time it occurs, you write "S" in your diary. You have no public word for it. No one else can feel it or observe it directly. The sensation itself is your only guide to whether tomorrow's entry of "S" is correct.

This seems like a perfectly sensible thing to do. But Wittgenstein asks: what makes tomorrow's use of "S" correct or incorrect? When you write "S" again, you are relying on your memory of the original sensation. But how do you know your memory is accurate? You cannot check the sensation against anything independent of your memory of it. The check and the thing being checked are the same.

Wittgenstein's point: "whatever is going to seem right to me is right, and that only means that here we can't talk about 'right.'" Without an independent standard, there is no distinction between using "S" correctly and merely thinking you are using it correctly.

Why private reference is incoherent

The argument does not say you cannot have private sensations. It says you cannot build a private language on them, where a private language is one whose terms refer to something only the speaker can in principle access.

Language requires a standard of correctness. A word means something only if there is a difference between applying it correctly and applying it incorrectly. For a public word like "red," other speakers can correct you. For "S," nothing can. A sensation you cannot re-identify reliably provides no standard at all. And a practice with no standard of correctness is not a language; it is just noise that resembles one.

What this means for inner experience

The argument's implications reach far. If phenomenal reports, statements like "I am in pain" or "I see red," draw their meaning from private sensation alone, they face the same problem. Wittgenstein's alternative is that even our talk about inner experience gets its grammar from public practice. "Pain" means what it means because of how the word is learned and used in a community, with behavioral criteria, social roles, and shared circumstances.

This does not deny that inner experience exists. It denies that inner experience alone can found meaning. Reports of inner states are meaningful because they are embedded in a form of life, not because they directly mirror a private show behind the eyes.