The Private Language Argument

Hello! Welcome back to our course.

In our last session, we grappled with the profound skeptical challenge posed by "Kripkenstein's" rule-following paradox. We ended on a cliffhanger: if no private, individual fact can determine what we mean by a word, then meaning itself seems to vanish. Kripke hinted at a "skeptical solution" which denies the premise that meaning is an individualistic, private affair.

Today, we will explore Wittgenstein's own development of this idea, which is one of the most famous and influential arguments in 20th-century analytic philosophy. This lesson directly addresses your learning outcome: to reconstruct the private language argument and its conclusion that meaning must be public.

This argument is a masterclass in philosophical analysis and a cornerstone of the linguistic turn in philosophy. It dissolves traditional philosophical problems by showing that they rest on a mistaken picture of language. Given your interest in logic and the foundations of thought, you will appreciate the rigor with which Wittgenstein dismantles a long-held philosophical assumption.

1. Defining the Target: What is a "Private Language"?

First, we need to be very precise about what Wittgenstein means by a "private language." He is not talking about a secret code or a personal diary that someone else could, in principle, decipher. He is targeting a much more radical philosophical idea.

A private language, in Wittgenstein's sense, is a language whose words refer to what can only be known to the speaker—their immediate, private sensations—and which is therefore necessarily and in principle unintelligible to anyone else.

This idea has deep roots in philosophy. Thinkers like Descartes and Locke conceived of the mind as a private, inner realm. On this view, my words for my sensations (like 'pain') get their meaning by referring to these private mental objects, which are hidden from everyone else.

To get a clear introduction to this concept and its historical background, please watch the beginning of the following video.

As the video and the Stanford Encyclopedia of Philosophy entry on Private Language explain, the idea that meaning is ultimately private underlies many traditional philosophical problems, such as radical skepticism about the external world or the "problem of other minds." Wittgenstein's goal is to show that this entire picture is built on an incoherent foundation.

2. The Core of the Argument: The Diary and the Criterion of Correctness

Wittgenstein asks us to imagine trying to create such a private language. This thought experiment is laid out in §258 of his Philosophical Investigations and forms the heart of the argument.

Let's imagine a diarist who wants to keep track of a recurring sensation for which there is no public name. They decide to focus their attention on the sensation, and write the sign 'S' in their diary each time it occurs. This act of "private ostensive definition" is supposed to fix the meaning of 'S'.

The crucial question is: on a later day, when the diarist has a sensation and writes 'S' again, how do they know they are using the sign correctly?

This is where the argument becomes incredibly powerful. For the use of 'S' to be correct, there must be a criterion of correctness—a standard against which the use can be judged. But in the private diarist's case, what could that standard possibly be? The only thing they have to go on is their own memory of the original sensation.

Let's watch the next part of the Attic Philosophy video, which explains this core thought experiment.

The problem is not simply that memory is fallible. Many early critics missed this point. The problem is deeper. In the private case, there is no possible distinction between remembering the rule correctly and seeming to remember the rule correctly.

As Wittgenstein puts it, "whatever is going to seem right to me is right. And that only means that here we can’t talk about ‘right’."

If there's no distinction between being correct and merely seeming to be correct, then the concept of "correctness" loses all meaning. The so-called "rule" for using 'S' is no rule at all. The initial "ceremony" of naming the sensation achieved nothing.

This is precisely the conclusion we reached in our last lesson with the rule-following paradox. The private diarist is in the same position as the person trying to convince the skeptic that they mean plus and not quus. There is no independent fact to appeal to that establishes the rule.

For a more rigorous, textual breakdown of this central argument, let's turn to the Stanford Encyclopedia of Philosophy.

3. Reinforcing the Point: The Beetle in the Box

To clarify his conclusion, Wittgenstein offers another famous analogy in PI §293: the beetle in the box.

Imagine a community where everyone has a box. In each box is something they call a "beetle." No one can ever look inside anyone else's box. Everyone claims to know what a beetle is only by looking at their own.

Wittgenstein points out that the word "beetle" could have a use in these people's language. But if it does, its meaning could not be the object in the box. Everyone could have a completely different thing in their box, or even nothing at all. The private object "drops out of consideration as irrelevant."

The analogy is clear:

• The Box = The private, Cartesian mind.
• The Beetle = The private sensation or mental object (like 'pain').

If our sensation-words get their meaning publicly, it doesn't matter what the "private object" is like, or if it even exists. Its meaning comes from its use in our shared language game.

Conclusion: Meaning as a Public Phenomenon

By dismantling the possibility of a private language, Wittgenstein delivers the positive side of the rule-following paradox. If meaning cannot be grounded in a private, inner state or object, then it must be grounded in our public, shared world.

The private language argument doesn't deny that we have private sensations. It denies that these private sensations can be the bearers of meaning for our language. Meaning is not a private act of naming; it is a public, social skill. It is rooted in our shared practices, our agreements in judgment, and our common "form of life."

Key Takeaways:

• A private language, in the philosophical sense, is one whose words for private sensations are in principle unintelligible to others.
• The argument against it (the diary example) shows that such a language is impossible because it lacks a public criterion of correctness. There is no distinction between correctly following a rule and merely seeming to follow it.
• The beetle in the box analogy illustrates that even if private objects exist, they are irrelevant to the public meaning of our words.
• The ultimate conclusion is that meaning is necessarily a public phenomenon, grounded in shared, observable practices and criteria.

Preview of the Next Lesson:

The private language argument is a paradigm case of a new philosophical method that emerged in the mid-20th century, a method you'll find throughout your study of analytic philosophy. Instead of trying to answer traditional philosophical questions head-on (e.g., "How do we know other people have minds?"), this method seeks to dissolve them by showing they arise from a fundamental misunderstanding of our concepts and our language. In our next lesson, we will step back and examine this broader shift in philosophical method, known as Ordinary Language Philosophy, and see how it changed the very questions philosophers ask.