Is a Word Only I Can Understand Still Language?

Imagine that whenever I experience a peculiar sensation available only to me, I write “S” in a diary. I never explain it to anyone, and there is no bodily response, measurement or public situation against which to compare it. The next time I write “S”, I rely only on memory to confirm that this is the same sensation. Has the sign acquired a stable meaning?

In Philosophical Investigations, Wittgenstein uses a related example to challenge the idea of a “private language”: one whose words could, in principle, be understood by only a single person because they refer to sensations that only that person could know. The problem is not that nobody else can decode a private shorthand. A code can still follow rules that are, in principle, decipherable. The deeper difficulty is that when a rule has no independent standard of application, the speaker cannot distinguish “I used it correctly” from “it seems correct to me”. If that distinction disappears, the notion of correct use no longer does any work.

The argument’s details and conclusion remain disputed. It does not deny that pain and emotion can be private experiences, and it does not imply that majority agreement creates meaning. Its target is a stronger proposal: that one inward act of naming can fix a word’s meaning completely, with no continuing norm for how the word is to be used.

My view is that language can be highly personal, but it cannot rest only on an uncheckable moment of self-confirmation. Words preserve meaning by entering practices that can be learned, corrected and continued. Even if the practice consists only of one person’s stable records, there must still be conditions under which a later use could be wrong.

https://plato.stanford.edu/entries/private-language/