抄録
Many of the philosophers who study the private language argument have thought that there must be common rules and criteria of correctness governing the use of words in a language. Wittgenstein, the founder of this problematic, begins his argument with a setting in which a person assigns a private sign (or “signs”) to her/his private sensation (s), and says this sign is meaningless because there can be no “is right/seems right” distinction within what is disclosed by introspection alone. In other words, a private language would lack the rules and criteria that a language (a word) must have.
It is doubtful, however, that from such a point of view, we can effectively deny the existence of a private language. First, those comments provide a sample of a private language and explain what it is like before they allegedly prove its impossibility. This is a contradiction because the very fact that we can understand the argument already demonstrates that the sample is not “private.” Second, in this notion of a private language, a sample word is considered to designate a sensation that is “private” to a speaker. The argument is that such a language is not a language at all because it lacks criteria according to which we might judge whether a word is used correctly or not; however, the same is true of any ordinary words that stand for ordinary feelings in our existing, public languages. If a speaker is rational, we believe what the speaker believes about her/his feeling.
Thus we conclude that the existence of a private language cannot be refuted by the argumentation based on the necessity of public criteria in a language. What we should notice is that the fact that any sample of private language can be understood by any body is the very evidence that private language cannot exist; the private language argument suggests the fundamental difficulty of empiricism. This is the most important point of the private language argument.
